Intel 9800758-02 User Manual

BASIC-SO

REFERENCE MANUAL

Manual

Order

No.

9800758-02

I

Intel Corporation,

3065

Bowers

1979

Intel Corporation

Avenue, Santa Clara, California

95051

r

Additional copies of this manual

Literature Department Intel Corporation 3065

Bowers Avenue

Santa Clara, CA

95051

or

other Intel literature may be obtained from:

The information in this document Intel Corporation makes no warranty

is

subject to change without notice.

of

any kind with regard to this material, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose.. Intel Corporation assumes no responsibility for any errors that may appear in this document. Intel Corporation makes no commitment to update nor to keep current the information contained in this document.

Intel Corporation assumes no responsibility for the use an Intel product.

No

other circuit patent licenses are implied.

Intel software products are copyrighted by and shall remain the property

duplication

or

disclosure

is

subject to restrictions stated in Intel's software license,

of

any circuitry other than circuitry embodied in

of

Intel Corporation. Use,

or

as defined in ASPR

7-104.9(a)(9).

or

No part of this document may be copied written consent

The following are trademarks

and the combination

of

Intel Corporation.

i

ICE iCS Insite Intel Intelevision Intellec

of

Intel Corporation and may be used only to describe Intel products:

of

ICE, iCS, iSBC, MCS,

ii

reproduced in any form or by any means without the prior

iSBC Library Manager MCS Megachassis Micromap Multibus

or

RMX and a numerical suffix.

Multirnodule PROMPT Prornware RMX UPI

~Scope

A108/0979/7500

FL

PREFACE

This manual describes and explains the features and conventions tended systems using the Intel Single Board Computer Systems using the Intel Real-Time Multitasking Executive (RMX-80).

This manual

Intel

and five appendices;

"Introduction" describes the general capabilities of BASIC-80, and its operating en-

vironment.

"Language Elements" describes the ways BASIC-80 represents its instructions, con-

stants, variables, arrays,

"Entering and Editing Programs" shows how you enter text and edit it, at time

entry or after storage.

"Error

error-resolving routines.

"Disk File files

"Commands and Statements" describes each command and order.

BASIC-80, as implemented on Intel Intellec

Systems Implementation Supervisor (ISIS-II), and on Intel

is

written for users who require concise, complete information about

BASIC-80 characteristics, and organizes this information into seven chapters

operators, and expressions.

Handling" shows how errors are identified, trapped, and used to initiate

Input/Output"

are created and used.

describes and sh0ws how random and sequential data

microcomp~ter

of

Intel Disk Ex-

development

statem~nt

in alphabetic

of

"Functions" describes each function in alphabetic order. "Appendix

tions, and codes in tabular format. "Appendix

variable names. "Appendix C: BASIC-80 Command Characters" lists BASIC-80 one-character

editing and control characters and their meanings. "Appendix D:

"Appendix E: Calling Non-BASIC-80 Subroutines" shows how to prepare and call

PL/M-80, FORTRAN-80, and 8080/S085 assembly language subroutines.

"Appendix F: Configuring RMX-80 BASIC-80" shows how to configure BASIC-80

with various hardware systems using

Other Relevant Intel Publications: The following manuals are required to use

• ISIS-II User's Guide, 9800306, which describes how to operate

Systems Implementation Supervisor" operating system (ISIS-II).

A:

BASIC-80 Error Codes" lists all BASIC-80 error messages, descrip-

B:

BASIC-80 Reserved Words" lists words that cannot be used in

ASCII Codes" lists ASCII codes and their meanings.

RMX-SO.

BASIC-80 with ISIS-Il

or

RMX-80:

the

Intel

iii

•

RMX-80

Real-Time Mulitasking Executive

•

RMX-80

operation

The following manuals may be required if you intend to call subroutines written in other Intel-supported languages:

• 8080/8085

describes the instructions and directives

User's Guide, 9S00522, which describes how to operate the Intel

(RMX-SO).

Installation Guide, 9803087-01, which describes installation and

of

the Intel Real-Time Multitasking Executive.

Assembly

Language Programming Manual, 9800301, which

of

the 8080/8085 assembler.

• 8080/8085 Macro Assembler Operator's Manual, 9800292, which describes how

to assemble (using

•

PL/M-80

conventions,

• ISIS-II

to use the

•

FORTRAN-80

instructions, conventions, and usage FORTRAN-SO programs.

Programming Manual, 9S00268, which describes the instructions,

PL/M-80

ISIS-II based

• ISIS-II FOR

how to use the machine code.

The following manuals are required of

BASIC-80 described in Appendix F:

•

iSBC

80/30 Single Board Computer Hardware Reference Manual, 9S00611,

which describes how

•

iSBC Manual,

RMX-80 configuration.

•

iSBC

which describes how configuration.

•

iSBC

016

9800279, which describes how to map memory to fit the sample

204 Flexible Diskette Controller Hardware Reference Manual, 9S00568,

80/10 Hardware Reference Manual, 9S00230.

ISIS-II) a program written in S080/S085 assembly language.

and

usage

of

PL/M-SO,

and

how

to

create

PL/M-80

programs.

Compiler Operator's Manual, 9800300, which describes how

PL/M

compiler to generate executable machine code.

Programming Manual, 9800481, which describes the

of

FORTRAN-80, and how

TRAN-80

Random

Compiler Operator's Manual, 9800480, which describes

ISIS-II based FORTRAN-SO compiler to generate executable

to

implement the RMX-80 sample configuration

to

configure the iSBC 80/30 under RMX-80.

Access

to

configure the iSBC 204 for the sample RMX-80

Memory

Board Hardware Reference

to

create

• iSBCBO/10A Hardware Reference Manual, 9S00230.

•

iSBC

80/20 Hardware Reference Manual, 9S00317.

•

iSBC

80/20-4 Hardware Reference Manual, 9S00317.

iv

CONTENTS

CHAPTER! INTRODUCTION

Operating System Interface . . . . . . . . . . . . . . . . . . . . .

Invoking BASIC-80 Manipulating Files from BASIC-80

Listing the Directory

Renaming a File. . . . . . . . . . . . . . . . . . . . . . . . . . .

Changing File Attributes

Deleting a File . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Loading a

Saving a Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER

Program.

2

TO

BASIC-SO

...........................

of

a Disk. . . . . . . . . . . . . . .

..

. . . . . . . . . . . . . . . . . . . . . . . . . . .

..

. . . . . . . . . .

. . . . . . . . . . . . . . . . .

LANGUAGE ELEMENTS

Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Statements.

Functions Representing Syntax

.........................................

Numeric

Constants.

Integer Constants

Decimal Integer Constants. . . . . . . . . . . . . . . . . .

Hexadecimal Integer Constants. . . . . . . . . . . . . .

Octal Integer Constants . . . . . . . . . . . . . . . . . . . .

Single-Precision Floating-Point Constants

Double-Precision Floating-Point Constants Variables String

String Constants . . . . . . . . . . . . . . . . . . . . . . . . . .

String Variables Converting Array Variables

String Arrays Operators and Precedence

Arithmetic Operators . . . . . . . . . . . . . . . . . . . . .

Relational Operators. . . . . . . . . . . . . . . . . . . . . .

Logical Operators . . . . . . . . . . . . . . . . . . . . . . . .

String Expressions

Numeric Expressions

String Expressions. . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

....................................

Data

...............................

Data

................

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

....................................

Data

...................................

Data

Operator

....

.....

.............................

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

...............................

..............................

............................

. . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . .

of

Evaluation.

.......................

......

.....

. . . . . .

PAGE

..

1-1 1-1

..

1-2

..

1-3

..

1-3

..

1-3

..

1-3

..

1-4

..

1-4

..

2-1

..

2-1

..

2-1 2-5 2-5 2-5

..

2-5

..

2-6

..

2-6

..

2-6

..

2-6

..

2-7 2-7 2-7 2-7 2-8

..

2-8 2-8

..

2-9 2-9

2-10

..

2-11

..

2-11

..

2-11

..

2-12 2-12

..

2-12 2-12

..

2-12

A Subcommand. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

E

Subcommand.

Carriage Return. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CHAPTER

ERROR

BASIC-80

Syntax Error Messages. . . . . . . . . . . . . . . . . . . . . . .

Overflow, Underflow, and Divide-by-Zero

Integer

Error

Trace Facility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Error Restarting

HANDLING

Error

Overflow Underflow

Divide-by-Zero . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operations

Trapping

Simulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Program

CHAPTER

DISK FILE

Sequential File

Opening a Sequential File. . . . . . . . . . . . . . . . . . . . .

Writing to a Sequential

Reading from a Sequential

Closing a Sequential File Random File

I/O

Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Defining a Random Opening and Closing a Random Disk Reading from a Random Writing to a Random

CHAPTER

COMMANDS

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

4

Messages. . . . . . . . . . . . . . . . . . . . . .

..................................

.................................

............................

..

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Execution

....................

5

INPUT

I/O

................................

IOUTPUT

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

File.

. . . . . . . . . . . . . . . . . .

File.

. . . . . . . . . . . . . . .

...

. . . . . . . . . . . . . . . . . .

I/O

Field-FIELD

I/O

File

...................

...........

File.

................

6

AND

STATEMENTS

........

. . . . . .

CHAPTER 7

FUNCTIONS

APPENDIX

A

BASIC-SO ERROR CODES

PAGE

..

3-6

..

3-6

..

3-6

..

4-1

..

4-1 4-1 4-1 4-2

..

4-2 4-2

..

4-2

..

4-3

..

4-4 4-4

..

5-1

..

5-1

..

5-2

..

5-2

..

5-3 5-4

..

5-4 5-4

..

5-6 5-6 5-7

CHAPTER

ENTERING

Entering Instruction Correcting Entry Editing

Program D Subcommand L Subcommand I Subcommand

H Subcommand. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

X Subcommand. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

S Subcommand

K Subcommand. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

C Subcommand. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Q Subcommand

3

AND

EDITING PROGRAMS

Lines.

Errors.

Text.

...............................

. . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . .

.. .. ..

.. ..

3-1 3-1 3-2 3-3 3-4 3-4 3-4 3-4 3-5 3-5 3-6 3-6

APPENDIXB BASIC-SO RESERVED WORDS

APPENDIXC BASIC-SO COMMAND CHARACTERS

APPENDIXD

ASCII CODES

APPENDIXE

CALLING NON-BASIC-SO SUBROUTINES APPENDIXF

RMX/80

BASIC-80

v

ILLUSTRATIONS

FIGURE

5-1

Random E-l Intel Numeric Representation E-2 8080/8085 Assembly Language Program E-3

PL/M-80

FORT~AN-80

E-4 F-l Sample Configuration F-2 Sample Configuration F-3

Sample Configuration GBASIC.CSD Module

1/0

Characteristics

Program.

TITLE

.................

. . . . . . . . . . . . . . . . . . . . . . .

Program

.....................

BQOPS.ASM Module

GBOOT.CSD Module

.......

....

PAGE

'

5-5 E-3 E-5

..

E-6

F-6 F-7

...

F-8

FIGURE

F-4 Sample BQOPS.ASM Module for PROM-Based

BASIC-80

F-5

Sample GBASIC.CSD Module for PROM-Based

RMX/80

F-6 Sample BQOPS.ASM Module for PROM-Based

iSBC

F-7 GBASIC.CSD Module for PROM-Based

iSBC

F-8 Sample User-Written 110 Driver Routine

.................................

BASIC-80

80/10

BASIC-80

80/10

BASIC-80

TITLE

........................

......................

....... ' ...............

......

TABLES

PAGE

F-9

F-IO

F-ll F-15

TABLE

2-1

BASIC-80 Commands

2-2

BASIC-80 Statements. . . . . . . . . . . . . . . . . . . . . .

2-3

BASIC-80 Functions

2-4

BASIC-80 Metalanguage Elements. . . . . . . . . . .

Numeric Data Types

2-5 2-6

BASIC-80 Operators in Order

TITLE

........................

.........................

of

Precedence

PAGE

..

...

2-1 2-2 2-3 2-5 2-6

2-10

TABLE

3-1

BASIC-80 Editing Subcommands A-I BASIC-80 Error Codes

D-l ASCII Code List. . . . . . . . . . . . . . . . . . . . . . . . . .

D-2 ASCII Code Definition. . . . . . . . . . . . . . . . . . . .

F-l Sample Configuration Jumper Wiring F-2 Sample Configuration Memory Requirements

TITLE

..............

......................

..........

PAGE

A-I

..

D-l

..

D-2

F-3

..

F-16

3-2

vi

CHAPTER 1

INTRODUCTION

BASIC-SO Series II Microcomputer Development Systems, which use the Intel Systems Implementation Supervisor (ISIS-II), and for Intel Single Board Computers, which use Intel's Real-Time Multitasking Executive applying the computational and input! output capabilities development system to a wide range of business, information handling, numeric analysis, and data processing applications.

BASIC-SO quirements for ISIS-II BASIC-80 include an Intellec Microcomputer Development System with at least requirements, both hardware and software, are described in Appendix F manual.

BASIC-SO capability, and full disk written functions can be defined, and up to Intel-supported languages language) and called from

is

Intel's implementation

can be used with either the ISIS-II or RMX/SO operating systems. Re-

4SK

of memory space, and one disk drive. RMX/SO

includes

21

commands,

I/O

(both sequential and random access). In addition, user-

(FORTRAN-SO, PL/M-SO, and

BASIC-SO.

of

disk extended BASIC for Intellec and Intellec

(RMX/SO).

39

statements,

25

It

offers a quick method

of

4S

functions, a line-editing

subroutines can

TO BASIC-80

of

the microcomputer

BASIC-SO

of

this

be

written in other

SOSO/SOS5

assembly

Intel integer, single-precision floating-point, and double-precision floating-point arithmetic standards are all supported, offering flexible combinations of processing

16

speed and accuracy (up to can have virtually as many dimensions as needed; the only limit on the number dimensions that can be specified

Hexadecimal and octal integer representation, combined with bitwise Boolean logical operators, make sophisticated mask operations easy. A full range

is

functions

The disk files, but also the ability to create, rename, change the attributes of, delete, and list the directory

BASIC-SO system with at least

available to provide flexibility in manipulating character data.

I/O

features include not only the ability to read from and write to disk

of

disk files without returning to the operating system.

requires

an

4SK

digits in the range ± 2.2 x

is

the 255-character program statement length.

Intellec or Intellec Series II microcomputer development RAM and ISIS-II operating system (version 3.4 or later).

-308

to ±

1.S x 10

308

).

Arrays

of

string

Operating System Interface

You can invoke for boot loading upon restart. Once BASIC the disk file-handling functions as well as the ability to load and save programs.

BASIC-SO

from ISIS-II, or configure

is

running, you have access to many

RMX-SO

BASIC-SO

in PROM

of

Invoking BASIC-80

Once you configure RMX/SO BASIC-SO, you restart.

will

always enter

BASIC-SO

upon

1-1

Introduction to BASIC-80

To

invoke BASIC-80 from ISIS-II, enter the name BASIC interpreter. Options also allow you to specify the name a program to be loaded after BASIC-80's work area. The format

BASIC-80

of

the command is:

of

the file that contains the

of

a file that contains

is

running, and upper memory limit for

BAS

IC-80

-BASIC

is

the ISIS-II command prompt.

enter the command.

BASIC

specifies the name

filename

is

an optional parameter

loaded and run after

MEMTOP(address)

is

an that number. interpreter, and less system.

Examples

[filename] [MEMTOP(address)]

It

is

displayed automatically before you

of

the file that contains the

that

specifies the name

BASIC-SO

is

running.

BASIC-SO

of

optional parameter that specifies the upper bound

BASIC-80 can use. Address can be either a decimal

It

must be greater

than

3800H plus the number

OBEBFH in a

48K

system

or

interpreter.

a file that

of

the memory

or

hexadecimal

of

bytes in the

OF6BFH in a

is

to be

64K

1.

If

the interpreter

-BASIC

2.

If

the situation

a disk in drive

-BASIC

3.

If

the

situation

using memory beyond address

-BASIC

If

a fatal ISIS-II error occurs while BASIC-80

initialized and the contents

is

in a file named BASIC

is

the same as

1,

but

you want to run a file named ANLYZE on

1:

:F1

:ANL YZE

is

the same as 2,

but

you also want to prevent BASIC-80 from

54400:

:F1

:ANLYZE MEMTOP(54400)

of

the BASIC-80 work area

on

a disk in drive 0 enter:

is

running, ISIS-II

is

lost, including any

is

re-

program editing you have done since you last entered a save command.

Manipulating Files from BASIC-SO

BASIC-80 lets you list a disk directory, rename a file, change the attributes of a file,

and delete a file. These functions can also be performed using

of course.

ISIS-II

or

RMX-80,

1-2

BASIC-SO

Introduction

to

BASIC-SO

Listing the Directory

To list the directory assumes drive 0 if you

DIR NAME.EXT

ALPHA ATTRIB BASIC 178

COpy DCOPY DELETE

DIR DSORT EDIT

.MAC INDEX NED RENAME

of

a Disk

of

a disk, enter DIR followed by the drive number. BASIC-80

don't

specify:

RECS LENGTH

31 38

64 32 37 46 11

5

.I

46 79 21

3728 4677

22571

7967 3961 4501 5728 1264

469

5669

469

2438

ATTR

Renaming a File

The RENAME command lets you change the name

to a new filename. The directory listing also changes to the new filename. In the example below, file

:FI:PROG

changes to :FI:MYPROG:

of

any file from an old filename

RENAME

":F1

:PROG"

to

":F1

:MYPROG"

Changing File Attributes

With the BASIC-80 A TTRIB command, you can protect a file from overwriting,

deletion, invisibility attribute, set the format attribute, or FORMAT commands. The system attribute, to a disk when the disk

or

being renamed by setting the write-protect attribute

"I",

the file will not appear when the directory

"F",

the file will copy to a disk formatted with the IDISK

"S",

makes the specified file copy

is

formatted by the FORMAT command or copied with the

"W"

.

If

you set the

is

listed.

If

you

COPY command.

For each attribute, the format

enabled, where X

ATTRIB

is

either W, I, S,

"filename",

is

"XO"

or

F. The format

"XO"I"X1"

if the attribute

of

A TTRIB

is

disabled,

is:

"Xl"

if it

Deleting a File

If

you want to get rid

it

and remove its listing from the directory. Once a file or program has been killed, it cannot be recovered. The format filename in quotation marks. For example, to delete a file named ANL disk in drive

1,

enter:

of

a file or program, you can use the KILL command to delete

of

the KILL command

is

KILL followed by the

YZ

on

the

is

KILL

":F1

:ANLYZ"

1-3

Introduction

to

BASIC-80

Loading a Program

BASIC-80

The LOAD command loads a stored in either ASCII a disk in drive

LOAD ":F1 :ANLYZE"

OK

You can now run, list, or edit the program.

Saving

The SAVE command copies your program from Intellec memory to disk. You must specify a filename, enclosed in quotation marks:

SAVE ":F1 :ANLYZ"

The SAVE command can also be used to list the contents printer or other output device. For example, to list the current file on a line printer, you would enter:

SAVE

1:

a Program

":LP:"

or

,A

BASIC-SO

internal format.

program from disk. The program can be

To

load a program named ANL YZE from

of

the current file on a line

4"4;0"1"

You can only write data to one disk in any disk drive each time you invoke

If

BASIC.

another, and try to write to the new disk, you lose all data on the The exception to this ble to change a disk on a drive if that drive has not been written to since

another drive has been written to.

gram writes

another and write on it, the contents however, your program wrote on a disk in drive 1 between writing on the

different disks in drive

you write to a disk in a given drive, remove that disk and insert

new

disk.

is

on systems with more than one drive.

As

an example, if your

on

a file in drive 0, and you then remove that disk, insert

of

that second disk

0, there would be no problem.

It

is

permissi-

BASIC-SO

will

be lost.

pro-

If,

1-4

There are no restrictions on reading from disks.

CHAPTER 2

LANGUAGE ELEMENTS

A BASIC-80 program consists

of

instructions, which tell BASIC-80 what to do, and data, which gives BASIC-80 the inform.ation necessary to do it. This chapter describes the different types

of

instructions and data, and shows how to represent

them.

Instructions

BASIC-80 performs work by interpreting user-provided instructions. These instructions are divided into three categories: commands, statements, and functions. These instruction types are described in the following topics; the individual instructions are described in detail in Chapters 6 and 7.

Commands

Commands are executed as soon as you enter them; they alter grams or files. Most commands can be used in program statements, but many them halt program execution and force variables to zero or null.

2-1

Table

lists the BASIC-80 commands.

Statements

Statements are executed when they are encountered during program execution. They

of

make up most commands.

the instructions

of

a program. Most statements can be entered as

or

direct entire pro-

of

Table 2-2 lists the BASIC-80 statements.

Table

2-1. BASIC-SO

Command ATTRIB

AUTO

CLEAR CONT DELETE

DIR

EDIT

EXIT KILL LIST

LOAD

Changes the attributes of a file. Automatically

statements. Sets aside memory Continues execution Deletes a

program. Displays a

files Specifies a program statement

be changed. Retu rns Deletes a file from disk. Displays a

program. Retrieves a file from disk.

Description

numbers program

line

or

list

on

of

a disk.

to

operating system .

line

or

for

strings.

after

BREAK.

lines

from a

all non-invisible

lines

of

a

Commands

ATTRIB AUTO

CLEAR CONT DELETE

DIR1

to

EDIT

EXIT KILL ":F1 :STAT" LIST

LOAD ":F1 :DATES"

"~F1

25,500

2000

700~875

170

300-400

Example

:STAT",

"W1"

Language Elements

BASIC-80

Table 2-1. BASIC-80 Commands

Command MERGE Combines file program with current

NEW

NULL PRUN

RENAME RENUM Changes program line numbers. RENUM RUN SAVE Stores program TRON TROFF WIDTH

program. Deletes

variables. Specifies nulls added to a line. NULL Executes program in

Changes

Executes program.

Turns on trace facility. TRON Turns off trace facility. TROFF Changes width

Description

MERGE

current

program, clears

ROM. PRUN

file

name. RENAME ":F1 :SOUP"

or

file on disk.

of

display line.

NEW

RUN SAVE ":F1:INVEN"

WIDTH

Table 2-2. BASIC-80 Statements

Statement

CLOSE DATA

DEF

DEFDBL

DEFINT

DEFSNG

DEFSTR

DEFUSR DIM END ERROR

FIELD FOR-NEXT-STEP

GET GOSUB GOTO

TH

EN-ELSE

IF-

INPUT

LET

Closes Identifies values that can be assigned

with a READ statement. Defines a user-written function.

Defines variable names starting with the given floating-point.

Defines variable names starting with the given

Defines variable names starting with the given floating point.

Defines variable names starting with the given names.

Defines non-BASIC subroutine. Allocates space for array variables. Concludes program. Simulates errors with given

number. Allocates space in random file buffer.

Creates a loop.

Retrieves data from

Transfers execution to subroutine. Transfers execution to line number. When the expression specified is true,

the statement executes; second statement executes.

1.

Prompts for terminal program

2.

Reads data from sequential file.

Assigns value to variables.

one

letter

Description

or

more files.

as double-precision

as integer.

as single-precision

as string variable

disk

file.

if

false, a

input

error

in

(Cont'd.)

":F1:TIME"

20

4EOOH

80

CLOSE 3 DATA

DEF

=

DEFDBL

DEFINT

DEFSNG B-H,

DEFSTR

DEFUSR 0 = DIM END ERROR

FIELD #3,20 FOR

NEXTI

GET#2,4 GOSUB GOT0400 IF

A>B THEN

ELSE PRINT

INPUT INPUT

LET A=52

Example

TO

":F1

Example

9,0,

"JUNE",

FNRT

(R1,

R-Z

I-N

K-O

12

TO

550

B,

A$,

R2)

X,

Y

4EOOH

AS

A$

5 STEP.5

2~0

">"

C

B$,

C$

R1

*R2/(R1 +

char (25,10,25)

1=1

A, #1,

:NUTS"

.33

2-2

BASIC-SO

Language Elements

Statement

LINE INPUT lSET

ON

ERROR

ON-GOTO

ON-GOSUB

OPEN OPTION BASE OUT POKE PRINT

PRINT USING

PUT RANDOMIZE READ

REM

RESTORE

RESUME RETURN

RSET STOP SWAP

WAIT

Table 2-2. BASIC-80 Statements

Description

Enters entire line from a disk left

justifies

Traps error-resolving routines.

Transfers execution for expression

Creates sequential Starts arrays at 0 Writes values Writes byte

1.

Displays

2.

Stores data in sequential disk file.

Displays

Stores data in random disk file. Initializes random number generator. Assigns values from DATA statements

to program variables. Comments in program

Resets pOinter for reading DATA statements.

Restarts execution after errors.

Transfers control back

following last GOSUB. Right Halts program execution. Exchanges values of two variables of

similar type. Halts execution until port changes.

errors

to

text

justifies

text

in random file buffer.

by

to

X.

to

X.

or

1.

to

I/O

ports.

memory location.

text

on terminal.

according

text

in random file buffer.

file.

branching

Xth line number

Xth subroutine

random

disk

to

given format.

text

to

statement

files.

(Cont'd.)

Example

LINE INPUT LSET

A$ = B$

to

ON

ERROR

ON

X GOTO

ON

X GOSUB

OPEN

"R", OPTION BASEO OUTOOFO,12 POKE

OA077, PRINT

A,

B,

PRINT

#4,

A$,

PRINT USING "$$##,##;

125.38,21.14.6.10 PUT

#3,

A$, RANDOMIZE READ

A,

K1,

10

REM

l$ = MK$

A1#,

THIS A REMARK

04H,

20 RESTORE

RESUME RETURN

RSET STOP SWAP

WAIT 1,

A$

GOTO

900

460,

480

220, 240,

1,

":F1:TRACE"

72

C

B$,

C$

B$

C$

l%,

Z

IS

B2#

OAH

260

Functions

ABS ASC

ATN COSl

CHR$

CINT COS CSNG CVD

CVI CVS

Table 2-3. BASIC-80 Functions

Returns

Absolute value. ASCII code

specified string. Arctangent, in radians.

Double-precision floating-point value. Character corresponding to the specified

code. Integer value Cosine, Single-precision floating-point value. Double-precision floating-point value equal to

8-byte string Integer value equal Single-precision floating-point value equal to

4-byte string

in

radians

of

the first character of the

A$

to

2-byte string

A$

ASCII

ABS(X) ASC(A$)

ATN(X)

CDSl

(X)

CHR$

(X)

CINT(X) COS

(X)

CSNG

(X)

CVD(X#)

CVI

(X%)

CVS(X!)

Example

2-3

Language Elements

BASIC-80

Table 2-3. BASIC-80 Functions (Cont'd.)

Functions

DSKF

EOF ERL ERR EXP FIX FRE

HEX$ INP INPUT$ INSTR$ INT LEFT$ LEN LOC

LOF

LOG MID$ MKD$

MKI$ MKS$

OCT$

PEEK

POS RIGHT$ RND

SGN SIN SPACES SPC SQR STR$ STRING$

TAB TAN USR VAL VARPTR

Returns

Number drive

-1 if end-of-file; 0 Line Error e Integer value Number

bytes in string space

String equal to hex value

Reads a byte from port (X) Inputs (X) characters from file Position

Integer value

Leftmost Character length Current record

Sectors read quential file

Number data sectors in sequential file

Natural log

J characters, starting at

B-byte string equal to double-precision floating-point variable (X!)

2-byte string equal to integer variable (X%) 4-byte string equal to single-precision

floating-point variable (X!) Octal equivalent Single byte from memory location Position Rightmost Single-precision random number between 0

and Sign Sine String String Square root String equal

Character

of Spaces

Tangent value

References Numerical value Memory address

of

128-byte sectors free on disk

(X)

number

to

the (X)th power.

1. of of

A$,

of

code

of

last error.

of

bytes in memory

of

(X$)

of

(X)

characters

or

X.

of

records in random file

of

(X)

of

cursor after last PRINT.

(1%)

(X) (X)

of

(1%)

spaces

of

(X%) spaces

of

to

X,

Y% times.

Y%

to

(X)

position on terminal

user

or

if

not

(for file

X).

last error.

(X).

(X)

or

X.

X$

(Y)

to

X.

A$

(X)

first

24

number

Number

character

(X$)

of

(X%)

within

(Y$)

(X)

of

(A$)

of

(X$)

number

written since last OPEN in se-

of

decimal argument

characters

(X)

times-or

of

(X)

subroutine 0

of

(X$)

of

(X)

in random file

I,

of

string

of

the

DSKF(X)

A

= EOF(X)

ERL ERR EXP FIX

of

FRE

HEX$(X%) INP(X) INPUT$ (X, INSTR$ INT(X) LEFT$ LEN LOC

X.

of

LOF (X)

LOG MID$

MKD$ (A$)

MKI$ (A$)

MKS$(A$)

OCT$(X) PEEK POS RIGHT$ RND

SGN SIN SPACE$(I%) SPC(X%) SQR STR$ STRING$ (Y%,

STRING$ (Y%, TAB TAN AX = USR VAL VARPTR(X)

Example

(X)

Y)

(X$,

Y$)

(A$,

X)

(X$)

(X)

(A$,

I,

J)

(X)

(dummy argument)

(X$,

1%)

(X)

X) A$)

(X)

12

(A1,

A2)

(X$)

2-4

BASIC-SO

Language Elements

Functions

Functions are built-in routines that return a value based on the argument or arguments supplied. They can be used to form expressions with either commands statements.

Table

2-3

BASIC-SO

lists the

includes both numeric and string functions.

BASIC-SO

functions. In addition to these, up to

10

user-written

or

functions can be defined with the DEFFN statement.

Representing Data

The instructions described in the previous topics tell BASIC-80 what to do; to carry out these instructions, you must also provide data in a specific fashion. Intel BASIC-80 includes constant and variable values, in either numeric or string format; allows these values to be grouped into arrays; provides for conversion from one data type to another; and allows these values to be combined into expressions using arithmetic, relational, and logical operators.

Syntax

BASIC-SO

accepts instructions and data in a specific format. This format, called

syntax, must be followed to obtain useful, predictable results.

of

superset language elements used to illustrate

ANSI Minimal BASIC syntax. The table below describes the meta-

BASIC-80 syntax.

Table 2-4. BASIC-80 Metalanguage Elements

Condition

An

instruction that requires no argument is

shown by itself in uppercase letters. If

an

argument must be provided, the descrip-

tion

of

follows the instruction.

If

the argument is enclosed in brackets.

If more than one type of argument can be specified, the choices are separated by ver-

tical lines.

If signify repetition.

the argument, in lowercase letters,

an

argument is optional, the description of

an

argument can be repeated, three dots

RESTORE

GOTOline

POKE

address, value

RESUME

SAVE

PRINT

READ

ON

[line number]

"filename"

expressionlvariable

data [,data] ...

variable GOSUB line [,line] ...

Numeric Data

BASIC-SO

categories, there are three types

point, and double-precision floating-point.

accepts numeric values as either constants or variables. Within these two

of

representation: integer, single-precision floating-

BASIC-SO

Example

[,A]

syntax

is

a

Using the DEFINT, DEFSNG, or DEFDBL statements, you can define a range of

letters to signify integer, single-precision floating-point, or double-precision

If

you

don't

floating-point numeric variables. it with a one-character suffix when you use the variable or constant letter name. you

don't

specify numeric type, the default

define numeric type, you can specify

is

single-precision floating-point, as if a

If

DEFSNG A-Z instruction had been given.

Table

2-5

summarizes

the

characteristics and methods of specifying numeric data

types.

2-5

Language Elements

Constants

Constants are numeric values that do not change during program execution. A constant can be a decimal integer, hexadecimal integer, octal integer, single-precision floating-point number, or double-precision floating-point number.

Table

2-5.

Numeric

Data

BASIC-80

Types

Numeric

Integer

Single-precision

(7

Double-precision floating-point (16

(decimal)

(hexadecimal)

(octal)

digits

precision)

digits

precision)

Type

floating-point

Range

-32768 +32767

Oto

FFFFH

Oto

1777770 ±1.2 x

±

3.4 x 10

±

2.2

x 10-

± 1.8 x

10-

10

to

38

308

38

308

Storage

Required

2 bytes 2 bytes -

2

bytes

to

4

bytes

to

8 bytes DEFDBL

Definition

DEFINT % X%

-

DEFSNG

Integer Constants

Integer constants are whole numbers in the range

constant requires two bytes

for integers and integer arithmetic

of

memory. Because the storage requirements are lowest

is

much faster than floating-point arithmetic, it's

a good idea to use integer representation wherever possible.

-32768

to 32767. Each integer

Decimal Integer Constants

To identify a constant as a decimal integer constant, add the suffix integer value.

Suffix

070

Examples

9463%

H

OFF4H

7720

0

!

X!

9436.5!

9.4365E03

#

X#

9436.5#

9.4365D03

to the decimal

2-6

Some decimal integer constants are:

Hexadecimal Integer Constants

Hexadecimal integer constants are identified by the suffix H following the numeric value. The characters

0-9 and A-F (representing the decimal values

hexadecimal digits. Each character represents 4 bits

be a decimal digit, so

it

may be necessary to

add

a leading

teger constants are:

Hexadecimal

1FH OC76H 7H

Decimal

Equivalent

3190

of

data. The first character must

o.

31

7

10-15)

are used as

Some hexadecimal in-

BASIC-80

Language Elements

Octal Integer Constants

Octal integer constants are identified by the suffix Q following the numeric value. The numerals octal iQteger constants are:

0-7

are

used as octal digits. Each digit represents 3 bits

of

data.

Some

Octal

7720 44440

7Q

Decimal

Equivalent

506

2340

7

Single-Precision Floating-Point Constants

Single-precision floating-point constants are identified by the suffix ! following the numeric value, by the presence point numbers

of

digits

accuracy.

Each single-precision floating-point constant requires Because this is stants, arithmetic,

and

it's

point operators. Some single-precision floating-point constants are:

142!

-1.414

6.259371

the

letter E identifying the exponent in scientific notation,

of

a decimal point in a number having seven

in

the

range ± 1.2 x

half

the storage required

because single-precision arithmetic

a good idea

to

use single-precision wherever possible for floating-

10-

38

to ± 3.4 x

by

double-precision floating-point con-

is

E-09

or

fewer digits. Floating-

38

10

are represented with seven

four

bytes

of

quicker

than

double-precision

or

by

memory.

Double-Precision Floating-Point Constants

Double-precision floating-point constants are identified by the suffix # following the numeric value, by having more

± 1.8 x

10

308

Each double-precision floating-point constant requires eight bytes

the

letter D identifying the exponent in scientific notation,

than

seven digits. Floating-point numbers in the range ± 2.2 x

are represented with

16

digits

of

accuracy.

10-

of

memory. Some

or

308

by

to

double-precision floating-point constants are:

-2.001317921012 11235813213455

24.2#

Variables

Numeric variables represent numeric values

tion. These

can

be

of

three types, like numeric constants: integer, single-precision

floating-point, or double-precision floating-point. Numeric variables are repre-

sented by one

or

two characters followed by

first character must be a letter; the second, which

alphanumeric character.

If

the variable name contains more besides a type identifier suffix, the rest No words used as

BASIC-80 instruction words may be used within variable names.

that

can

change during program execu-

an

optional type identifier suffix.

is

optional, may be any

than

two characters

of

the variable name characters are ignored.

The

2-7

Language Elements

If

a variable

NEW,

Individual variables can be specified by individual type identifier suffixes, which

override group type identifiers used to specify blocks these suffixes.

is

referenced before it has been assigned a value, its value

RUN, CLEAR, LOAD, and MERGE instructions set all variables to zero.

of

variables. Table

is

zero. The

2-5

shows

BASIC-80

Blocks single-precision, statements. The general form of these statements is: DEFxxx m[-n], where n letter A through Z, (Le., the block L-Q a certain letter or letters may be defined as one type.

The variable default type at the start should define them type identifiers override any variable block type assignment.

Note that A$, type for variables beginning with the letter A the same variable.

To economize on memory space and execution time, you should use integer representation rather rather

of

variables beginning with specific characters can be specified as integer,

or

double-precision with the DEFINT, DEFSNG, and DEFDBL

and m is is

of

a given program.

at

(%

for

AOJo,

A!, and

than

double-precision, when this

any letter A through Z that precedes n in the alphabet,

legal, but Q-L

is

single precision, as if a DEFSNG A-Z had been executed

the start

integer,!

AI

than

single-precision representation,

is

not). In this way, all variables beginning with

If

certain variables should be of another type, you

of

the program to prevent errors. In all cases, the

for single-precision, and I for double-precision)

are four different variables.

is

single precision, then A and

is

possible.

If

the default variable

and

single-precision

is

A!

any

are

String Data

BASIC-80 accepts strings either constants or variables.

of

characters as data. Like numeric values, strings can be

String Constants

A string constant marks cannot be used within string constants. String constants can be up to characters long. Some string constants are:

"This

"48, 23H, 373799"

is

a group

is a string

of

characters, enclosed in quotation marks. Quotation

constant."

255

String Variables

String variables are string values which can change during program execution. A

is

string variable name followed by first two are read.

String variables can contain strings BASIC-80, however, there command must some examples of assignments to

A$ = "Enter

B$ = "40

NAMES$ =

$.

If

be

* 1. 7234E +

one or more characters, the first

more

than

two characters are entered as a variable name, onlv the

is

only storage space for 100 characters. The CLEAR

used to increase the amount of available string space. Here are

strip.g variables:

next data

"Warren,

string"

3"

Mark, Evan"

of

from 0-255 characters. When you first invoke

of

which must be a letter,

2-8

BASIC-SO

Language Elements

Converting Data

It

is

sometimes useful to convert one type these conversions with the HEX$, OCT$, CHR$, STR$, VAL, CVD, CVI, CVS, CDBL, CSNG, CINT, MKS$, MKD$, and MKI$ functions.

of

data into another.

BASIC-SO

suppo. I...,

The HEX$ and

OCT$ functions return a string

respectively, that represent the numeric argument. The

of

string function returns the numeric value

CHR$ returns the The CVI,

sion floating-point,

decimal digits that represent the decimal value of the argument. The VAL

of

the string argument, if the string

ASCII equivalent

of

an integer argument, between 0 and 255.

CVS, and CVD functions convert a given string into integer, single- preci-

or

double-precision floating-point numeric values, respectively. These functions are used to retrieve numeric values from the when doing random disk

110.

of

hexadecimal and octal digits,

STR$ function returns a

is

a number.

input/

output buffer

The MKI$, MKS$, and MKD$ functions convert integer, single-precision floatingpoint, and double-precision floating-point numeric values, respectively, into a string. These functions are used to store humeric values in the input/output buffer when doing random disk

You can convert a numeric variable (integer, single-precision floating-point, double-precision floating-point) to any

110.

of

these types by using the variable in an

or

ex-

pression with the CINT, CDBL, or CSNG functions:

A# =

CDSl

l4!

= CSNG

VAR5 = CINT (VAR5)

(A%)

(l4)

Array Variables

An array

is

a group

of

variables identified by the same name, specified by subscripts that define their position in the array. An array variable can have as many dimensions as will fit on a single line. An array variable

is

specified by following a variable name with as many subscripts as there are dimensions. A subscript must be an integer value, and enclosed within parentheses

square brackets.

If

there

is

more

or than one subscript, separate them with a comma. Expressions can be used to specify subscripts; they are rounded to integer form. Here are some array variables:

X

(10)

R1

(5,4)

Y(I,1)

SA(I + 3,X(10))

BASIC-SO defined as BASE

normally indexes arrays from zero; that is; the first element in

O.

To start arrays

at

one in BASIC-SO, enter the instruction OPTION

1 in your program before you dimension or reference any arrays.

an

array

is

The DIM statement allocates array space and specifies the maximum allowable

If

subscript for a given dimension. formally dimensioned, examples

An attempt

of

the DIM statement:

DIM X(15) DIM R1(12,8) DIM K(17,24)

to

specify

BASIC-SO

an

array variable whose subscripts are larger than the dimensioned value, or which exceed OF

RANGE error

message~

an array variable

allocates

10

in the default mode, causes a SUBSCRIPT OUT

an

index

is

referenced before it has been

of

10

for each dimension. Some

2-9

Language Elements

String Arrays

Like numeric arrays, string arrays can be dimensioned with the DIM statement. The format for dimensioning a string array

If

you

If

this value

DIM A$(5,25,40)

don't

execute a DIM statement, a default

is

then exceeded, an error message will result.

Table

2-6. BASIC-80

is

the same as for numeric arrays:

of

10

for each subscript

Operators

in

Order

of

Precedence

is

assumed.

BASIC-80

Order

1.

2·.

3.

4.

5.

6.

7.

8.

Operator Expressions in parentheses. Exponentiation, as shown in the example,

where A is raised to the B power. Negation, represented by the minus sign. Multiplication and Division, represented by

an

asterisk

Integer

backslash (

verted to integer truncated to an integer.

Integer Modulus, represented by MOD. Both arguments are converted into integers. The the first is divided by the second.

Addition and Subtraction, represented by

(+) and minus

Relational Operators. These are listed without precedence. For all relational operators, the result is -1 false. The arguments A and B must strings

Equals sign: Used to

(*)

and a slash

division,

).

Both arguments are con-

result is the remainder when

(-)

signs.

or

both numeric variables.

(I)

respectively.

represented

values and the result is

if

true, and 0 if

test

for equality.

be

by

both

Example

(A+B)

AtB

-A

A*B AlB

a

A\B

AMODB

A+B

A-B

A=B

2-10

Greater Than: Used to test magnitude between two arguments. The sign faces the posited greater

Less Than: Used to test magnitude between two arguments. The sign faces the posited

Not Equal: Used to test for inequality be-

two

tween Greater Than or

magnitude down to the argument.

Less Than magnitude up to the

argument.

In

the Logical Operators below, the arguments are converted to 16-bit, signed complement integers converted to the same format. The operations are performed one paring the nth bit

of

X with the nth bit of

arguments.

Equal To: Used to test

or

Equal To: Used to test

in

the range -32768 to

large end

value.

small end of the

less.er value.

level

of

the second

value

of

the second

+32767.

Y.

The result of the operation is

of

the

bit

at a time, com-

A>B

A<B

A><B A<>B

A=>B A>=B

A=<B A<=B

two's

BASIC-80

Table

2-6.

BASIC-SO

Operators

in

Order

of

Precedence

Language Elements

(Cont'd.)

Order

9.

10.

11.

12.

13.

14.

Operator

Logical NOT, used argument.

Logical and the nth bit

Logical Y equals

Logical exclusive OR, used the nth bit of X or the nth bit both.

Logical implication, used to test of

Logical equivalence, used to bit

AND,

used

of

OR, used to test

1.

X is on, then the nth bit

of X equals

the

to

Yare

nth

to

invert a given

test

if the nth bit

both on.

if

the nth bit of X or

to

of

Y is on.

test

bit

of

Y.

test

if

Y =

1,

if

the nth bit

if the nth

of

X

either

but not

NOT-1

1ANDO=O

150RO=15

15XOR7=

OFOFOH

OFOFH

Example

=0

8

IMP

OOFFH=OFFFOH

EQV.OOFFH=OFOOFH

Operators and Precedence of Evaluation

Complex expressions may be formed by combining constants and variables with arithmetic, logical, relational, and string operators. precedence to insure orderly and predictable evaluation when analyzing complex pressions. This order

of

precedence may be overridden within the parentheses are evaluated first. The numeric operators (arithmetic, logical, and relational) are listed in order

of

precedence

BASIC-SO

by in

follows an order of

parentheses; any elements

Table 2-6.

ex-

Arithmetic Operators

There are seven arithmetic operators in arithmetic operation on two numeric expressions. They are evaluated before the relational or logical operators, and if two operators

BASIC-SO, they are evaluated from left to right. Table

by

of

operators in order

precedence. Some examples

A = 8*(C*2.49) K1=(L+M) RS

= (83*

Et

S

.S)

BASIC-SO,

of

arithmetic operators are:

each performing a familiar

of

equal precedence are found

2-6

lists the arithmetic

Relational Operators

There are six relational operators in

-1

expressions and return a

if the premise structions to direct program execution according to either result. The relational operators are evaluated after the arithmetic operators, and if two operators with the same order Table

IF IF

IF

of

precedence are given in an expression, they are evaluated left to right.

2-6

lists the relational operators, and some examples are given below:

(A*2.2)<>8*81

THEN INT(A1) = INT(81) THEN A>

B THEN

IF

8>(C*

BASIC-SO,

220

A=B

VA#)THEN

which test relationships between two

is

true, a 0 if it

is

false. You can write in-

340

2-11

Language Elements

Logical Operators

The logical operators NOT, AND, OR, XOR, IMP, and EQV are operators that compare the nth bit evaluated after the arithmetic and relational operators; therefore, arithmetic expressions resolve to a number which operator test can be used with logical operations. of

the same precedence in a single expression, they are evaluated left to right. Table

2-6

lists the logical operators in order of precedence'. Some examples

operators, used in complex expressions, are shown below.

String Operator

The relational operators may be used with strings to compare them according to ASCII order. to the first used with strings: the concatenation operator two

of

argument X with the nth bit

IF

A>=3.5X

IF

B=1

IF

(A-B) AND

or

more strings joined together.

A$ =

B$+C$

OR

X > 3 THEN

OR B=2 OR B=3 THEN

If

part

(B+3)

strings

of

the longer, then the longer

THEN STOP ELSE

of

unequal length are compared, and the shorter

of

argument

is

compared with another number. A relational

If

there are two logical operators

01=0

2750

ELSE

280u

IF

(A AND

is

greater. There

(+).

This operator defines a string

B)

THEN CLOSE 2

is

Y.

They are

of

the logical

is

identical

one operator only

BASIC-SO

as

Expressions

Except for the command and stateqlent instructions, all of the language elements previously discussed can be combined to form expressions. Depending on the type of constants, variables, and operators used, expressions can be classed as numeric or string.

Numeric Expressions

In BASIC-80, numeric expressions are created with numeric variables, constants, functions, and operators. Variables are initialized with values with assignment statements, or with

INPUT statements during program

execution.

Any function which returns a numeric value can be used in a numeric expression. Strings can only be used if they are converted to a number. Numeric expressions can use arithmetic, logical,

K(I) = B*SOR(X) IF

A>12.1 THEN C = C + 1

IF PEEK (2FFFH) AND

or

relational operators. Some numeric expressions:

OCH

THEN PRINT

String Expressions

String expressions can be specified in BASIC-80 using string constants, string variables, relational operators, and the concatenation operator

If

tion operator combines two strings into one. characters, execution halts and

an

error message

sions are:

A$ =

"NAME:" + NAME$ IF B1$>R$ THEN 81$ = R$(I)=R$(I) + S$(I) +

""

"DONE"

the resulting string

0, and may be assigned other

"ON"

(+).

The concatena-

is

longer than

is

displayed. Some string expres-

255

2-12

CHAPTER 3

ENTERING

With BASIC-80, you can create new programs by entering statements line by line, or you can access saved programs from disk storage. you can use the ISIS-II BASIC-80 Text Editor

RMX/80

The following topics show how to use ISIS-II BASIC-80 Text Editor to aid program development.

BASIC-80 does not have a Text Editor.

AND

BASIC-80 programming features and the

EDITING PROGRAMS

If

you're using ISIS-II BASIC-80,

to

alter

new

or saved instruction lines.

Entering Instruction Lines

When you invoke BASIC without specifying a file name, there

is

ready

to

The system sists

of

a line number from 0 to 65529 followed by the language elements (program statement, constants, variables, operators, functions, etc.). number alone after a line with that number has been entered with text, that line deleted.

You can enter statements in any order. To review the statements in a program, use the

LIST command.

You can have given increment, by using the mand, When you end the statement with a carriage return (CR), it prints the next line number and again waits. To stop the automatic line numbers, enter a Control-C.

BASIC displays the line number and waits for you to enter the statement.

BASIC-80 provide line numbers, starting

accept commands or program statements. A statement con-

It

displays the statement in numeric order.

AUTO command. After you enter the AUTO com-

is

no program

If

you type a line

at

a given number, with a

to

run.

is

If

AUTO generates a line number that already exists in the program, it prints

asterisk (*) after the line number.

If

the existing statement. You can use Control-I

is

of each line Control-I, the cursor or print head moves to the beginning of the next column.

BASIC assumes a width WIDTH command.

To enter more

If

you want to format the program so that additional statements appear on separate lines (but are still (LF) key to move to the beginning number doesn't end until you enter CR.

To BASIC-80 doesn't try to execute such lines,

of

put

a comment in a BASIC-80 'program, enter REM after the line number.

divided into 8-character-wide columns. Each time you press

than

part

times, up to the 255-character line-length limit; the program statement

you enter a Control-C, the existing line

as

a tab key

of

one statement per line, separate each statement with a colon (:).

of

the same numbered program statement), use the Line Feed

If

you enter a statement, what you enter replaces

is

unchanged.

if

you want to format your statements. The width

72

characters. You can change the width with the

of

the next display line. You can do this any

but

they become part

of

the program.

Correcting Entry Errors

If

you make

key

to

pressing CR).

an

error while entering a line, you can correct it by using the RUBOUT

erase characters (as long as you haven't entered the line into memory by

an

3-1

Entering

and

Editing

In the Command Mode, the RUBOUT key deletes the last entered character each time you press it, and backspaces the cursor on a CRT.

RMX/SO

CR, the program statement

BASIC-SO,

RUBOUT echoes the last-entered character.

is

entered without the rubbed-out characters.

On a teletype, or with

If

you then press

enter new characters and then press CR, the new characters appear in the line.

If

BASIC-SO

you

Suppose you enter 52 instead of 55.To erase the

30

A=8*52 •

30

A=8*5

If

you press RUBOUT again, the 5

30

A=8*

To change

30

A=8*52 •

30

A=8*

30

A=8*37 •

52

•

to

37,

press RUBOUT twice, then

•

is

deleted:

2,

press RUBOUT:

3,

7:

When using the Edit Mode, RUBOUT works somewhat differently. Refer to the Editing

Program Text Section for details.

Control-R displays the line as corrected, still waiting for more input:

30

A--=8xx*522537 (Control-R) A = 8*37

To cancel a line, simply press Control-X.

Editing Program

Intel ISIS-II or entire lines. The Editing Mode has its own set 3-1

briefly describes each

terminal beeps and the character

BASIC-SO

Text

has an Editing Mode used to change individual characters,

of

subcommands and syntax. Table

of

the subcommands.

is

ignored.

If

an illegal character

is

entered, the

3-2

Table 3-1.

Function

To delete text: To insert text: To

delete all characters to the right of the cursor

and insert To insert characters at the end of the line: To search for a character: To To change next n characters to y characters: To restore To restore original line and restart Edit Mode: To print balance of line and restart Edit Mode: L To leave Edit Mode and keep changes: To

edited To delete unwanted characters: To place one logical statement line on two

physical lines:

To leave next n characters unchanged:

text:

delete all characters until specified character:

original line and leave Edit Mode:

leave Edit Mode, keep changes, and print the

line:

BASIC-80Editing Subcommands

or

more

Syntax

[integer] 0

I character [character. .. ]

H character [character ... ]

X character [character ... ]

[integer] [integer] K character [integer] C character [character ... ]

Q

A

E

Carriage return

Rubout Line Feed

[integ.er] space

S character

BASIC-SO

Entering

and

Editing

Complete editing variables to zero or null. editing mode with the BASIC-80 returns

of

a line replaces the old line with the edited line. This resets all

To

end editing without losing prior variable values, exit the

Q subcommand after the line number has been printed.

to

command level, variable values are unchanged

and

any editing

changes are lost.

There are three ways to enter the Editing Mode:

1)

Type

EDIT

line number, and BASIC-80 returns the line number requested.

you press the space bar, the cursor moves

to

the desired location in the instruc-

tion line.

2)

When entering text, type a Control A instead

of

a carriage return. This causes a

carriage return, a space, and the computer prints an exclamation point. The cur-

at

sor points ing the space bar. last line,

3)

If

BASIC-80 encounters an instruction line with a syntax error during program

execution, it will halt

the first character

If

and

you

can't

you use CONTROL-A after listing a program, it edits the

change line numbers.

and

print

of

the sequence, and can be advanced by press-

an

error message

of

the format: SYNTAX ER-

ROR IN (line number). Below the error message, the computer returns the line

and

number,

In the Edit Mode, pressing deleted. Use the D subcommand to delete characters

In the explanatory sections edited by each subcommand. The

head,

and

all characters are shown as they appear

the line may be edited.

RUBOUT will echo characters,

b~low,

a typical line

"."

,in

the Edit Mode.

of

program text

indicates the position

on

the terminal. Such editing sub-

but

is

of

the cursor

they are

edited and re-

commands as D, L, Carriage Return, Escape, and so on are represented theses: (CR), (ESC), (D), (4SE) to avoid confusion.

You should

tryout

other examples to gain facility with the editor.

or

in

these

If

not

print

paren-

or

of

In the following sequence hypothetical program. Line

edit subcommands,

40 returns a syntax error message, since it needs a

PRINT instruction following ELSE,

40

IF

A>B THEN

120

OR

ELSE

and

should not contain OR:

"NULL

SET"

we

will be editing line 40

of

D Subcommand

The D subcommand

counted as characters. just the remaining characters are deleted. The argument n to 255, and the default value backslashes, i.e.,

The syntax

of

[integer] D

In the example below, line 40 returned a SYNTAX ERROR message when the program ran.

BASIC-SO displays the error message and enters the Edit Mode. ing the space incorrect character

40

IF

A>B THEN

40

IF

A>B THEN

The command( 3D) (press 3, then

is

used to delete characters to the right

If

there are less than n characters to the right

is

\characters\

the D subcommand

bar, the text

is

of

line

encountered.

120

OR

ELSE

120.

of

the cursor. Spaces are

of

the cursor,

is

an integer in the range 1

1.

The deleted characters are printed enclosed by

.

is:

By

40

is

displayed character by character until the

"NULL

D)

results in:

SET"

press-

a

40

IF

A>B THEN

120

\OR\

•

3-3

Entering

and

Editing

L Subcommand

BASIC-80

The L subcommand prints the rest subcommands. The cursor command

to

display previously edited text and restart editing at the beginning

is

of

the original line, and waits for further editing

to the left

of

the first character. You can use the L sub-

of

the

line:

40

IF

A>B

THEN

40.

120

ELSE

"NULL

SET"

I Subcommand

The I subcommand inserts characters after the last character typed. Each character typed after typing I

ESCAPE key. To end insertion and leave the Editing Mode, press the Carriage

the Return key. Characters may be deleted when using the I subcommand by pressing

RUBOUT key.

the The syntax

of

I character [character] ...

Suppose you want space bar until you reach the proper point:

40

IF

A>B

and then enter:

(I) PRINT (ESC) (L)

And you 40

IF

A>B

is

inserted

at

the I subcommand

to

insert the word

THEN

120

ELSE.

will see:

THEN

120

ELSE PRINT

the current cursor position. To end insertion, press

is:

"PRINT"

"NULL

into the previous example. Press the

SET"

H Subcommand

The H Subcommand deletes all characters to the right the insertion mode, like the I Subcommand. When through inserting characters, enter

(ESC) to end insertion

of

The syntax

H Character[Character] ...

If

you want to change the message

"UNDEFINED

the H subcommand

SET",

or

(CR) to end editing.

is:

"NULL

you can use the H Subcommand to do it. Move the cursor to

the proper point with the space bar:

40

IF

A>B

THEN

120

ELSE PRINT

Enter (H) "UNDEFINED

40

IF

A>B

THEN

120

SET"

(ESC) (L):

ELSE PRINT "UNDEFINED

SET"

of

the cursor, and then enters

in the previous example to

SET"

X Subcommand

The X subcommand prints the rest

of

end command is used

the line, and enters the insertion mode; as for the I subcommand. This sub-

to

add new text

the insertion mode.

of

the line to be edited, moves the cursor to the

at

the end

of

instruction lines. Execution

is

as in

3-4

BASIC-SO

Entering

and

Editing

The syntax

Returning to the previous example, if you wish to add text

of

the X subcommand is:

X character [character] ...

at

the end

of

the given in-

struction line, use the X subcommand:

40

•

Enter (X)

40

IF

A>B

Enter new

40

IF A >B

THEN

text

THEN

120

ELSE PRINT "UNDEFINED

at

the

cursor-;A;

120

ELSE PRINT "UNDEFINED

B (ESC) (L):

SET"

•

SET";A;

B

S Subcommand

The S subcommand examines characters to the right of the cursor., to find the nth

occurrence default searches, printing all characters encountered. When the nth occurrence fied character specified character

The syntax

of

the specified character, where n

is

1.

This subcommand skips the first character to the right of the cursor and

is

an integer in the range 1 to 255; the

of

is

found, the cursor stops

is

not found, the cursor stops at the end

of

the S subcommand

is:

at

the character.

If

the nth occurrence of the

of

the line.

the speci-

[integer] S character

The S subcommand can be used with an example to find the nth occurrence

we

specified character. Suppose

"E"

the 3rd letter

40

•

Enter (3SE):

40

IF

A>B

At

this point, the other editing subcommands may be used.

in line 40:

THEN

120

want to move the cursor to the space occupied by

ELSE •

of

the

K Subcommand

The K subcommand functions like the S subcommand except that it deletes all

of

characters passed over until the nth occurrence deleted characters are enclosed in backslashes.

The syntax

of

the K subcommand

[integer] K character

is:

The K subcommand may be used on our example.

of

P,

1st occurrence

40

•

Enter

and print backslashes:

(1

KP)

the specified character. The

It

will

eliminate all text up to the

\40\

IF

A>B

THEN

Enter (L)

40

PRINT "UNDEFINED

120

ELSE.

SET";A;

B

3-5

Entering

and

Editing

C Subcommand

The C subcommand changes the next n characters to the specified character(s).

of

integer is specified, the character immediately to the right

the cursor

is

changed.

If

BASIC-SO

no

The syntax

of

the C subcommand is:

[integer] C character [character ... ]

In our previous example, line 40 was reduced to:

40

PRINT "UNDEFINED

This can be changed to print

Move

the

cursor to:

40

PRINT.

Enter

(2C)

RE

(L)

40

PRINT "REDEFINED

40

•

SET";A;

"REDEFINED

SET";

8

A;8

SET"

with C:

Q Subcommand

The Q subcommand restores the original line, as it was prior to editing,

the editing mode. Note

This subcommand returns the user

edited command. This subcommand only works when editing program lines.

that

if

an

instruction

to

is

edited with Q, the changes are lost.

the command mode without executing an

and

leaves

A Subcommand

The A subcommand restores the original line and prints the original line number

is

below. Editing lines.

When the A subcommand

40

PRINT "UNDEFINED

restarted. This subcommand only works when editing program

is

used with the previous example, the result

is:

SET". Enter (A) (L) 40

IF

A>B THEN

120

ELSE

"NULL

SET"

40.

E Subcommand

The E subcommand exits the editing mode. The edited line replaces the original line. When the E subcommand

40

PRINT "UNDEFINED SET"

(The E subcommand is entered)

Carriage

A Carriage Return exits the editing mode, The edited line replaces the original line.

Return

is

used with the previous example, the result

and

prints

the rest

of

the line being edited.

is:

3-6

CHAPTER 4

ERROR

If

you enter improper instructions, syntax, or formats, BASIC-80 issues an error message. This chapter explains what these errors mean, how they may be trapped with the ON ERROR statement and pinpointed with the TRON, TROFF, ERR, and ERL instructions, and how errors may be simulated with the ERROR statement.

HANDLING

BASIC-80 Error Messages

When BASIC-80 encounters an error in a program, it displays an error message. Appendix A lists the error messages and error codes, and describes their meaning. These errors stop program execution. You can use the to correct obvious errors, add error-trapping instructions, or use the trace facility.

Syntax

If

message, and enters the Edit Mode:

Error

BASIC-80 detects a syntax error,

10

LET

20

PRINT A RUN SYNTAX ERROR 10

•

Messages

A=

IN

10

it

stops program execution, displays an error

BASIC-80 editor at this point

You can now change line 10, as described in Chapter without making any changes, and to preserve the variable values in the program,

Q.

If

type variable values are lost.

you enter any other editing subcommands (including Carriage Return)

3.

To leave the Edit Mode

Overflow, Underflow, and Divide-by-Zero

In BASIC-80, the single- and double-precision floating-point overflow, underflow, and divide-by-zero errors do not halt program execution.

Overflow. Single-precision floating-point overflow occurs when the magnitude of a

(±)

single-precision numeric value exceeds floating-point overflow occurs when the magnitude

(±)

E20*1

D200*1

1.79 x

E20

D200

1.79769313486231

value exceeds generated, the message OVERFLOW ble magnitude for the given representation with the appropriate sign

ex~cution

The following examples show single- and double-precision overflow:

proceeds.

10

A = 1

20

D#

= 1

30

PRINT A;D#

RUN

OVERFLOW OVERFLOW

3.402824E + 38

308

10

(1.79D308). When a value of this magnitude

3.4 x

is

displayed, a value equal to the largest possi-

D +

308

38

10

(3.4E38). Double-precision

of

a double-precision numeric

is

assigned, and

is

4-1

Error

Handling

BASIC-SO

Underflow. Single-precision floating-point underflow occurs when the magnitude

of

a single-precision numeric value

precision floating-point underflow occurs when the magnitude of a double-

is

precision numeric value

is

magnitude

generated, no message

less

than

is

less than

(±)

2.2 x

is

printed, the result

10-

(±)

308

1.2 x

(2.2D-308). When a value of this

10-

is

defined

38

(1.2E-38). Double-

as

zero, and pro-

gram execution continues.

is

Divide-By-Zero. Divide-by-zero precision overflow protocol, except that the message printed

Integer

Operations

handled identically to single- and double-

is

DIVIDE-BY -ZERO.

Integer overflow and division by zero are treated as normal errors. Program execution halts. Integer overflow occurs when a value greater than 32767.49 or less than

is

-32768.49

Error

converted to integer representation. Integer underflow cannot occur.

Trapping

Error trapping allows you to trap and correct errors. Errors normally halt program

is

execution and return error messages. When given before an error

encountered, the ON ERROR GOTO statement transfers program execution to a specified line number when an error occurs, and suppresses any error messages other than those you specify and write yourself. specified location to identify and correct errors. In the following example, when is

entered in response to the INPUT statement, an error occurs and the user-written

You can write an error-service routine at the

-3

error message displays:

10

ON ERROR GOTO

20

INPUT A

30

PRINT SQR{A)

40

GOTO 100 110 120

RUN

20 PRINT PRINT RESUME NEXT

"ARGUMENT "ENTER

100

NEW

CANNOT VALUE."

BE

NEGATIVE."

? 3

1.732051

?

-3

ARGUMENT CANNOT ENTER NEW

VALUE

BE

NEGATIVE

?

Suppose there

is

no error routine (made up of lines

10,

100,

110,

and

120)

in

the

above example, and you wish to identify this particular error. The ERR and ERL

A)

functions return the error code number (see Appendix

error occurs in, respectively. In this way, you can identify the kind

and the line number the

of

error and the line it occurs in and write individual error handling routines for individual errors. The program below uses ERL and ERR to identify the location and nature of any error.

In the following example, the routine at line

100, which identifies one specific error (division by zero) and the line

ON ERROR statement enables the error-service

number in which it occurs:

4-2

BASIC-80

10

ON ERROR GOTO 100 20 30 40

GOTO 100 110 120

RUN

?

13

INPUT PRINT

A

521

A

20 PRINT IF 11=ERR RESUME NEXT

"Error";ERR;"at

THEN

PRINT

line";ERL

"Division

by

zero"

4

? 0

Error

11

at

line

30

Division

by

zero

?

Trace Facility

The TRON and TROFF (trace execution

of

each line. The line number of each program statement executed displayed in brackets. The preceding example would run like this after entering TRON and then RUN:

on

and trace off) commands are used to examine the

is

Error Handling

[10]

[20]? • 5 (CR)

[30]

10.4 [40] [20]? • [30]

7.428571 [40] [20]? • 0 (CR) [30] [100] [110]

Division

[120] [40] [20]? •

The ON

ERROR

7 (CR)

Error

11

at

line

30

by

zero

OOTO 0 statement has a special meaning. When entered outside error handling routines it disables any prior handled

normally-error

entered inside

an

error handling routine, it allows normal handling of a given error

messages are displayed and execution

or errors, as shown in the example below.

10

ON ERROR GOTO 100

20

30

40

50 100 110 120 130

RUN

INPUT PRINT PRINT STOP

A,B AlB SQR(8-A}

IF ERR<>11

8=1 RESUME ON ERROR GOTO 0

THEN

130

? 2,0

2

Illegal Ok

function

call

in

40

ON

ERROR OOTO so that errors are

is

lialted. When

of

The error routine (lines 100-130) sets B to 1 when the divide-by-zero error occurs,

but allows other errors to interrupt operation in a conventional way.

The non-fatal floating-point overflow and divide-by-zero errors are trapped like

of

other errors. No messages are displayed in this case, and the results

the calcula-

tions are undefined.

4-3

Error Handling

BASIC-SO

Error Simulation

BASIC-SO provides a statement that can simulate any errors which produce code. When the

ERROR BASIC-SO acts as if the specified error demonstrates how

10

ON ERROR GOTO

20

INPUT

30

B = A *

40

PRINT B

50

GOTO

70

IF

11

80

RESUME NEXT

If

line 40

is

replaced with:

40

ERROR

Program

control transfers to line

ERROR

A

.3842 20

= ERR THEN PRINT

11

statement

can be used

70

"Division

70

regardless

is

encountered during program execution,

had

occurred. The example below

to

test

an

error handling routine.

by

zero"

of

the result

of

the operation in line

30.

Restarting Program Execution

You can restart program execution after it has halted with the RUN instruction, and after instruction. Remember

an

error in

that

RUN sets all variables

an

ON

ERROR routine with the RESUME

to

zero.

or

an

error

CONT

RUN restarts program execution number

is

specified, or

at

the specified line number.

CONT restarts execution at the line after a STOP, END, countered.

CONT will also restart program execution after

at

the lowest-numbered line

It

can be used

of

a program if no line

at

any time.

or

CONTROL-C

an

error, but

it

is

en-

will try to

execute the erroneous line. RESUME can only be used when the halt occurs in

an

ON ERROR routine.

It

given following the error-resolving routine pointed to by the ON ERROR instruction.

It

can be used three ways: RESUME to begin execution RESUME NEXT to begin execution RESUME followed

by

a line number

to

at

the line following the erroneous line;

begin execution

at

the erroneous line;

at

any other line.

is

4-4

CHAPTER 5

DISK FILE INPUT/OUTPUT

BASIC-SO random. Sequential random

Because ISIS-II and RMX/80-DFS format (:Fn:name.ext, where n BASIC-SO

• DIR, which lists the files

• RENAME, which changes the name

• A TTRIB, which changes the attributes

• KILL, which deletes a disk file (it

For more information about

Guide.

Although both sequential and random on disk, sequential haven't worked with disk files before, it would probably be better to start with quential

includes two types

I/O

lets you specify where in the file you read or write.

BASIC-SO

also gives you access to disk file-handling commands:

the name must be different because delete lines from a program).

110

to learn the principles.

runs under ISIS-II and RMX/SO, filenames correspond to the

I/O

of

disk file Input/Output operations: sequential and

lets you read or write a file from the beginning to the end;

on

a disk

of

a disk file

of

a disk file

is

actually the system DELETE command, BASIC-SO

ISIS-II filenames or operations,

I/O

allow you to create, read, and write files

is

somewhat simpler in concepts and operation.

is

the drive number).

includes a DELETE command to

see

the ISIS-II User's

If

but

you

se-

Sequential File

BASIC-SO numbers and strings must open the file, execute a series statements, then close the file.

A sequential file you must close the file and open it again with the opposite attribute. Any tion that immediately follows

Sequential

is

1/0

I/O

allows you to build sequential data files containing

of

up to

255

characters. In general, to use sequential

of

INPUT (to read) or PRINT (to write)

open either for input or output. To switch from one to the other,

an

OPEN statement starts at the beginning of the file.

110

you

opera-

Opening a Sequential File

You open a sequential file with the OPEN statement. to be opened for input or output, assigns it a file number, and specifies the filename. Up to

six

files can be open

specifies output does not exist, it again without closing it first.

To open an input file named :Fl:DATES and assign

OPEN "1",#1,":F1:DATES"

at

one time.

If

you attempt to do so, an error message results.

If

the file named in an OPEN statement that

is

created. Once a file

It

specifies whether the file

is

open, it cannot be opened

it

file

number

1:

is

5-1

Disk File

Input/Output

BASIC-SO

String and numeric expressions can replace any

OPEN M$,FN,

DN$+

"OUTPUT"

This statement opens a file for either input or output, depending

"I"

or

"0")

and

(it must be either must be from 1 to 6). The name should be

":FO:"

followed by the

through

six

characters

":F9:",

OUTPUT.

assigns the file number represented by FN (it

of

the file

depending

of

the parameters:

on

the value of M$

is

the value

on

of

the string variable DN$ (it

how many drives you have, or null)

NOTE

Remember that opening a file for output destroys

an

existing file

of

same name.

Writing to a Sequential File

After you open a sequential file for output, you can write data to it with the

statement. that a number (preceded by

To

print a series

You can also use the full formatting capabilities of the

PRINT

If

you open an existing file for output, its contents are deleted.

statement

of

constants and variables to file 3:

#3,

"Today's

is

being used to write to a sequential disk file, the file

#, followed by a comma) follows the word PRINT.

date is

";MO$;OA;",";YR

PRINT

USING statement:

To

the

PRINT

specify

PRINT

Refer to Chapter 6 for further details of

#3

USING, "###,##;"234.41 ;81.20;4.68

PRINT

USING.

Reading from a Sequential File

After you open a sequential file for input, you can read data from it with the INPUT and LINE INPUT statements. read from a sequential disk file, the file number (preceded by comma) follows the word

The INPUT statement reads the specified number the disk file. Numeric values (in the disk file) can be separated by a blank, comma, carriage return, or line feed.

String values can be enclosed in quotation marks, or given as unquoted strings. Quoted strings terminate commas, carriage returns, line feeds, or if they exceed

Assume, for example, that disk file represents a carriage return-line feed pair in the disk file):

"R1"

,200,

"R2"

,2200,

"R4"

,.47

After the file string value to

is

opened for input, the following INPUT statement would assign a

R$

and the subsequent numeric value to R:

To

specify that these statements are being used to

# and followed by a

INPUT

on

or

LINE INPUT.

of

values (numeric or string) from

the quote marks, while unquoted strings terminate

255

characters in length.

#2

"R3"

contains the following

,10000

data

(a new line

on

5-2

INPUT #2,R$,R

If

executed four times, it would read all eight values.

BASIC-80

Disk File

Input/Output

LINE INPUT,

on

the other hand, ignores blanks, commas, and quotation marks, and reads everything between the current file position and the next carriage returnline feed, logical line, LINE line. The string ample, assume

or

up to

255

characters.

INPUT

is

assigned to the single string variable specified. In the preceding ex-

that

instead

will read to the end of

If

the last INPUT did not read to the end of a

of

that line before reading the next

the INPUT statement shown, the following statement

was executed:

LINE INPUT #2,R$

The value

This statement data values, such

ment created with the

The

of

R$

would be:

"R1"

,200,

"R2"

,2200,

"R3"

,10000

is

useful for reading from a file that consists of lines, not individual

as

lines from an ASCII-saved BASIC-80 program file,

ISIS-II text editor.

INPUT$ function reads the specified number

or

a docu-

of

characters from a sequential

file:

10

OPEN

20

PRINT INPUT$ (3,1)

30

CLOSE

40

END

This program reads the first 3 characters from the file them.

If

you execute line

"1",#1,":F1:MONTHS"

#1

20

again, INPUT$

:Fl

:MONTHS and prints

will

read the next 3 characters.

is

set to

-1.

When you read the last value from a file, an end-of-file flag can be tested with the end-of-file flag

tion halts.

To

prevent surprises, you can test for an end-of-file with the EOF func-

EOF

function.

is

set, BASIC-80 issues an INPUT PAST END message and execu-

If

you try to read data from a disk file after the

This flag

tion and then branch to an appropriate routine:

250

IF

EOF

(1)

300 310

CLOSE 1 PRINT

"END

THEN

300

OF INPUT

DATA"

Closing a Sequential File

Once you read or write the desired data from or to a sequential file, you must close the file. This can be done in several ways.

CLOSE command closes one

The

CLOSE 1,2,5

or

more files:

If

you enter CLOSE with no file number, all open files are closed. The END state-

and

EXIT

ment and the NEW

commands close all disk files. After closing a file, you

can open it again for input or output, with the same or a different file number.

5-3

Disk File

Input/Output

BASIC-SO

Random File

Random flexible because you can move back and forth within a disk file. These are the key differences:

• To get

• Random

• Because all data in random files

• You must use special assignment statements to

• Unless you simply want to read

I/O

data

must understand how

110

floppy disk sector. You must specify how this 128-byte string fields and assigned to string variables.

strings calculations with dom file, you must first convert it to a string. Special functions are provided do this.

buffer. This fixed-length; the special assignment statements accommodate variables longer

which record you want to read or write.

that

or

shorter than the specified field.

I/O

requires a bit more care and coding than sequential

from random disk files to BASIC-80 variables and vice-versa, you

BASIC-80 uses

operations (GET and PUT) always read or write all

represent numbers into numeric values if you want to

them.· Likewise, if you want to write a numeric value

is

due to the fact that the fields you define in an

110

buffer space.

is

treated as string data, you must convert

put

a string variable into an

or

write records

in

sequence, you .must specify

I/O,

128

is

divided into

I/O

buffer are

but

bytes

is

do

to

that

more

of

any

a ran-

to

110

of

are

a

1/0

Buffers

BASIC-80 reserves space assigned to each open file (when an OPEN statement record from a random file using GET, the 128-byte string a variable. define what portions

To emphasize: the usual variable and line delimiters ing. All than buffer are set

It

is placed in the 110 buffer assigned to that file, and it

128

bytes from the specified sector are placed

128

bytes were written to the sector, the remaining character positions in the

to

ASCII blanks (hexadecimal

Defining a Random

When a sector has been read into the 110 buffer, it exists as a 128-byte string. You must define how the string statement specifies to to string variables (initially they treated as a 128-byte string).

The FIELD statement tells starting with the first, are to be associated with a variable. For example, assume you have opened a random file, assigned it the file number 3 (the works just like in sequential that the first the string variable N$, enter the following FIELD statement:

20 characters of each sector contain a name. To assign these

for

six

I/O

buffers, each

of

the string are to be assigned to what variable

20)

1/0

Field-FIELD

is

to be assigned to a variable or variables. The FIELD

BASIC-80 what character positions in the buffer correspond

128

bytes long. One buffer

is

executed). When you read a

is

not assigned directly to

is

up to you to

or

variables.

(",

CR) have no special mean-

in

the 110 buffer.

.

If

fewer

must be string variables, because the sector

BASIC-80, for a given file, what character positions,

OPEN

command

110), and read the first sector from the file. You know

20

bytes to

is

5-4

FIELD

#3,

20

AS

N$

BASIC-SO

Disk File Input/Output

or

The FIELD statement can precede

20

contain those first

bytes until the FIELD statement. (A similar definition must be done when writing to a random file with the statement, obviously, must precede the which variable

Any number

or

variables to write to the disk.)

of

fields

can

be defined with one FIELD statement. In the preceding

example, for example, let's assume

follow the GET statement, but

PUT

statement; the FIELD

PUT

statement so that BASIC-80 will know

that

character positions 21-29 (the 9 bytes

following the name field) contain a social security number. To define the first

N$

doesn't

of

fields

20

bytes as N$ and the next 9 bytes as SS$, enter the following FIELD statement:

#3,

20

AS

N$, 9 AS

Not

FIELD

only

can

you define all statement for the same buffer. variable with character positions in the buffer, the last-executed one applies. several FIELD statements are executed

SS$

128

bytes this way, you can enter more than one FIELD

If

more

than

one FIELD statement associates a string

that

specify different string variables,

If

however, all the field definitions are effective.

5-1

Figure variables,

summarizes this relationship

and

shows the sequence

record, assign the first

20

bytes to N$,

of

disk record,

of

BASIC-80 statements necessary to read a

and

the next 9 bytes to

110

buffer, and string

SS$

(the remaining

99 bytes are ASCII blanks). The program shown opens the file, reads the field record, and prints both N$ and

SS$.

10

OPEN

20

GET'3, 30 FIELD 40 PRINT RUN

JONES, JOHN J. 517317010

OK

1/0

BUFFER FOR

FILE

"rMBER

3

IJ,o,N,E,s,,J

DEFINI~~~~

"""1·1f-------N$------·

IJIOIHINI

"R",

3,

"F1:PERSON"

1

1#3.1

20

AS

N$, 9

AS

N~,

55$

TRANSFERS CONTENTS

(20

BYTES)

55$

GET

STATEMENT

OFRECORDTO

1/0

BUFFER

IJI·I

RECORD

1 OF

:F1:PERSON

11511171311171011101 I I I I I ...

I..--ss$------~BLANKS---+-1

(9

BYTES)

Iltl

(REMAIN ING

99

BYTES)

I I

Figure

5-1.

Random

I/O

Characteristics

5-5

Disk File Input/Output

Opening and Closing a Random Disk File

As

with sequential disk files, you must open random disk files before you can write

to them isn't opened for either input you can read from

or

read from them, and close them when you're through. A random file

or

output, however; once it's open for random

it

or

write

to

it interchangeably.

BASIC-SO

I/O,

To open the

OPEN

Any

of

OPEN

This opens the file whose name I/O

and assigns it the file number represented by the numeric variable F.

As

with sequential numbers); and EXIT commands close all open files;

Reading from a Random

You can retrieve entering the GET statement, you must specify the file you want to read.

file

":FI

"R",

:PERSON"

#3,

":F1 :PERSON"

for random

110

and assign it file number

3:

the parameters can be variables:

"R",

F,

FN$

is

represented by the string variable FN$ for random

I/O,

the CLOSE statement can specify a file number (or

CLOSE by itself closes all open files. The END statement and the NEW

STOP does not.

1/0

File

data

formatted and stored on disk with the GET statement. When

You can also specify the record you wish to read by entering the record number after the file number.

If

you

don't

specify the record number, BASIC-80 either reads the first record, if there has been no read operation since the file was opened, or reads the record that follows the last record read. To read the first record from file I:

GET #3,1

To read the next record:

GET

#3

As

described earlier (in

FIELD), the GET statement reads

dom file by the

OPEN statement. The FIELD statement specifies which portions the buffer are to be assigned as

string data).

Assume, for example, you have a file written as a random SON. The first 20 characters

"110

Buffers" and "Defining Random

128

bytes into the

to

string variables (all data in random

of

each sector contains a name, and the next 9

I/O

110

Fields-

buffer assigned to the ran-

of

I/O

files

is

stored

liD

file named :FI :PER-

characters contain a social security number. The following statements open the file, define which parts

10

OPEN

20

FIELD

30

GET #3,1

of

the buffer correspond to variables, and read the first sector:

"R",

#3,

":F1 :PERSON"

#3,

20

AS

N$, 9 AS

SS$

To print the name:

40

PRINT

N$

5-6

BASIC-SO

Disk

File

It's

not

quite so simple to print

I/O

files, however, because they are represented as strings. You must convert each

string

that

represents a number to its corresponding numeric value, either integer,

single-precision floating-point,

or

do calculations with numeric values from random

or

double-precision floating point. The CVI, CVS,

and CVD functions, respectively, perform this conversion.

is

Assume that there

an additional 2-character field following the 9-character social

security number that represents the number of hours worked in the previous week.

The following statements open the file, define the fields, read the first (or next)

record, and increment the variable

10

OPEN

20

FIELD

30

GET

40

PRINT N$; SS$;

50

HW = HW + CVI (H$)

60

PRINT

"R",

#3,

#3

"TOTAL

#3,

":F1

20

AS N$, 9 AS SS$, 2 AS H$

"HOURS HOURS

HW

by the number of hours worked:

:PERSON"

=";

HW

CVI (H$)

Input/Output

The two characters defined as H$ are converted to an integer.

To

convert a string to a numeric variable, the number of string characters must equal the number required to store the corresponding numeric data type:

Integer Single-precision value Double-precision value

If

the number

fewer

than

required,

execution halts.

CVI CVS CVD

of

string characters represented by the argument of the function

an

ILLEGAL FUNCTION CALL error message

If

the string variable is longer than required, the extra characters are

2 bytes 4 bytes 8 bytes

is

printed and

ignored.

Writing to a Random

To

store data in a random disk file, you follow the same sequence of

FIELD statements as when reading from a random disk file. The

128

bytes

writes the The FIELD statement, however, defines fixed-length fields in the

the data to be written to disk into the statements: LSET and RSET. LSET left-aligns a variable RSET right-aligns it. ded with ASCII blanks

of

the

In

both

(20H);

1/0

File

I/O

buffer to the disk file.

I/O

cases, if the variable

if

the variable

OPEN

PUT

I/O

buffer. To get

buffer, there are two special assignment

in

the buffer field, and

is

shorter than the field, it

is

longer than the field, it

is

truncated.

of

bytes

is

and

statement

is

pad-

For

example, assume you have opened a file for random

3, and defined the first

20

characters as N$. You must use LSET

I/O,

assigned it file number

or

RSET to place

values in the buffer:

10 OPEN

20

FIELD

30

LSET N$ =

40

PUT #3,1

"R",

#3,

20

A$

":F1

AS N$

:PERSON"

This technique may be used for storing variables for use in another program, linked to

the first program with the RUN statement (see description

of

Whatever the length

is

less

than

20

characters long, the remaining characters

A$, its leftmost

(20H). Statement 40 writes all

128

bytes

20

characters are now identified as N$.

of

the

I/O

buffer to disk file number

of

N are set

of

RUN, chapter 6).

to

ASCII blanks

#3.

If

A$

5-7

Disk

File Input/Output

Remember that random disk files are stored as strings. Just as you must convert

that

fields

represent numeric values when you read them (using

eVI,

CVS, or CVD), so must you convert numeric values to their corresponding strings when writing to a random file, using the MKI$, MKS$, and MKD$ functions. Again, you must be sure

of

to allow for the number

bytes required

to

store the three numeric data types.

BASIC-SO

Integer Single-precision value Double-precision value

MKI$ MKS$ MKD$

2 bytes 4 bytes 8 bytes

For example, assume that you open a random file and define two fields: the first 2 characters as P$ and the next 4 characters as C$; the first field represents a part number and the second its cost. The following statements open the file, set to a variable number

10 20 30 40 50

The part number,

P A and

5:

OPEN FIELD LSET RSET PUT#5, 1

"R",

#5,

P$

C$

equal to a variable CO, then write the two values to file

#5,

":F1

:PARTS"

2 AS

P$,

4 AS

C$

= MKI$ (PA)

= MKS$ (CO)

of

course, must be between -32768 and 32767, and the cost

P$ equal

will

be

accurate to 7 digits. Two other functions are related to random disk 110: LOC and LOF. LOF returns

of

the number

was last read

the last sector in the file; LOC returns the number

or

written.

of

the sector that

5~8

CHAPTER 6

COMMANDS

AND STATEMENTS

ATTRIB

The A TTRIB command changes certain specified attributes You can protect any file from writing or deleting or renaming by enabling the 'write protect' attribute, and you can later disable this attribute to alter or delete the specified file. The formats for these two operations are given below.

You can also enable Refer to the using ATTRIB with system, format, and invisible attributes.

To protect a file from writing, deletion, and renaming:

ATTRIB ":Fdrive number:filename",

To write to, delete,

ATTRIB

ISIS-II

":Fdrive

or

disable other file attributes with the A TTRIB command.

User's Guide, File Control Commands, for information on

"W1"

or

rename a previously protected file:

number:filename", "WO"

of

BASIC-80 disk files.

AUTO

The AUTO command automatically generates a line number each line when you are entering a program. The first operand specifies the number of

the first line entered after the AUTO command; the second, which

specifies the increment. Both operands default to

AUTO [first line

To number lines starting with

AUTO

To number lines with an increment

AUTO 300,50

If

AUTO generates a line number that already exists in the program, the generated

is

number line in the program, enter Control-C to stop the

followed by

J[,

increment]

10

in increments

of

50

starting with line 300:

an

asterisk. To erase the existing line, enter CR; to leave that

10.

of

10:

AUTO process.

at

the beginning of

is

optional,

CLEAR

The CLEAR command sets all variables, arrays, and function definitions to zero,

If

and closes files. zero and string variables will be null. The first expression ment, and the value

variables are referenced after a CLEAR, numeric variables

of

this expression becomes the string space,

is

specified as

in

bytes.

an

will

argu-

be

CLEAR [expression[,address]]

6-1

Commands and Statements

If

a second expression to BASIC. This number highest memory location used storage space are available.

is

specified, it indicates the highest memory location available

is

similar to the MEMTOP option.

is

unchanged. At sign-on only

If

not specified, the

100

bytes

of

string

BASIC-SO

CLEAR

will

reserve 2000 (decimal) bytes for string space, and

any memory address above

2000,

ODOOOH

ODOOOH.

will

not allow BASIC to use

CLOSE

The CLOSE statement concludes statement for

an

open file disassociates the file name and the file number used to open the file, but the file may be opened again under the same or another file number. Close without options closes all files.

The END, NEW, MERGE,

arguments) statements close all disk files automatically, but

CLOSE [[I] 10

OPEN

20

GETI3,1

30

FIELD #3,20,AS N$, 9 AS SS$

40

PRINT 'N$,SS$

50

CLOSEI3

RUN

JONES,

Ok

file

"R"

JOHN

number

,13,

"F1

J.

I/O

activities for one or more disk files. A CLOSE

LOAD, RUN (without

[,[1]

file

number]

:PERSON"

517317010

... ]

F)

and CLOSE (without

STOP does not.

6-2

CONT

The CONT command continues program execution after a Control-C, a STOP, an ERROR interruption,

of

an

because resumes

error, BASIC-80 will try to re-execute the same line again. Execution

at

the statement after the break occurred unless input from the terminal was interrupted; in this case, the prompt if the program was modified during the break, but variable values may be changed.

CONT

In the example below, the program expects a numeric input and Control-C.

ENTER NEXT INTEGER STRING ?41

tC

BREAK OK CONT

?

37

IN

240

or

an END statement has been executed.

(1)

is

reprinted. Execution cannot be continued

If

execution halts

is

interrupted with a

BASIC-SO

Commands and Statements

DATA

The DATA statement prefaces lines

and

command may be numeric, strings, ("

")

they may

blanks are ignored.

assigned as values to variables. The data is separated by commas

or

quoted strings.

not

contain commas (,)

DATA

instruction lines may be located anywhere in program

of

data

that are read sequentially by the READ

If

strings are

or

semicolons (;) and leading

text. BASIC maintains a pointer which keeps track read. This pointer program read.

is

RUN.

It

can be moved with the RESTORE command.

DATA

[,

number I string

10

DATA

20

DATA

30

DATA

40

FOR

50

READ X, A$, Y

60

PRINT X; A$; Y

70

10

IS

LESS

44

IS

GREATER

1.71S Ok

is

It

numbeq

10, IS LESS 44,

1.7,

1=1

TO 3

THAN

EQUAL

set to the first data element

increments

string

IS GREATER

"IS

THAN

TO 1.7

to

subsequent DATA elements when its elements are

literal I quoted

THAN,

EQUAL

77

-32

77

THAN,

TO

",

string]

-32

1.7EO

of

string

...

and

not

surrounded by quotes

or

trailing

of

the next DATA element

to

be

the first DATA statement when a

DEF FN(X)

The DEF FN(X) statement defines arithmetic or string functions for later use in program text. The name given to the function must be FN followed by a valid variable

name. The variable(s) given are the arguments used within the function. Any oneline expression can be used. User-defined functions can be string, and any number parameters must be specified when the function Functions may

DEF

not

function

be redefined.

name

of

arguments are allowed. The correct number

is

[(variable [,

variable

... ])]=

The rules for function name are the same as for variable name.

10

DEF

FNAC

20

FOR X = 1 TO

30

PRINT FNAC (X),

40

NEXT X

50

END RUN .159155 .954931

(X) = (1/(2*3.14159))*X

10

.31831

1.11409 1.27324 1.4324

.477465

.63662

.795776

1.59155

of

any type, arithmetic

or of

referenced within a program.

expression

6-3

Commands and Statements

DEFSNG DEFDBL DEFSTR DEFINT

BASIC-SO

The DEFSNO, DEFDBL, DEFSTR, and that

a given block

letter

of

variable names. statements specify single precision floating point, double precision floating point, string, according to

in which m represents

Z. These two letters represent the boundaries

If

must L,

and

DEFXXX m

n

is

not

used, only variables beginning with letter m are specified.

follow m in alphabetic sequence; in other words, blocks may be defined as D

or A to

0,

10

DEFSTR S

20

DEFDBL D

30

DEFINT I-N

of

letters will designate a specific

The

DEFSNO, DEFDBL, DEFSTR,

integer representation, respectively. Blocks the

syntactic

[-n][,m[-n]]

but

not

format

any

letter, A through Z, and n represents any letter B through

as P to A

given below:

...

or

Z to M.

DEFINT

of

a block

statements are used to specify

data

type when used as the first

and

DEFINT

of

letters are specified

of

letters between m

The

and

n argument

n.

to

DEFUSRn

The

DEFUSRn assembly-language, PL/M-SO, USR function. The argument n may be an integer from 0 to 24; if given, 0 is assumed.

statement

Two

examples

is

used to specify the starting address

or

Fortran-SO subroutine so they may be called by the

of

DEFUSRn

statements are given below:

of

no

an

SOSO/SOS5

argument

is

DEFUSR = DEFUSR7 =

Because value for decimal values in a

The program below shows how DEFUSR defines a subroutine. Refer

for further details

of

an

10

INPUT

20

IF

30

DEFUSR11 = A

10

REM This

20

REM Integers,

30

REM Returns

40

DEFINT A-Z

50

DEFUSR 1 =

60

PRINT

70

INPUT A,

80

P R IN T

90

RESULT =

100

PRINT

110

END

OFOOOH

1%

the way BASIC-SO represents numbers internally, 32767

integer expression. The following code can be used to specify higher

A>

DEFUSRn

"ENTER

32767

THEN A =

of

using DEFUSR.

program

"Enter

B,

"A

=

";

USRo/01

"A+

B+C+

statement.

ENTRY ADDRESS

A-65536

asks

for

passes

the

OEOOOH

three

C

A;

them

result.

numbers:"

"B

=

";

(A, B, C)

="

B;

"C

RESULT

IN

three

to

USR1, and

= " ; C

DECIMAL";

A

is

the largest

to

Appendix E

6-4

BASIC-SO

Commands and Statements

DELETE'

The DELETE command removes specified instruction lines from program

or

block

of

single line

lines may be deleted,

as

shown in the syntactic format and

tex,t.

A

example below. Instruction lines prior to and including the specified line may be deleted by adding a dash line numbers specified as end points must exist.

DELETE

10 PRINT CHR$(12)

20 30 40 50

60

70 DELETE-40 OK LIST

50 60 70

OK

DELETE OK

LIST 50 60

Ok

line

PRINT:PRINT:PRINT REM THIS PROGRAM FINDS THE AVERAGE REM

OFTHREE INPUT PRINT END

INPUT PRINT (A + B + END

INPUT PRINT

A,B,C

(A+

A,B,C

70

A,B,C

(A+

(-)

before a line number. When deleting a range

numberlline

NUMBERS

B+C)/3

C)l3

B+

C)/3

number-line

If

not, an error results.

numberl-line

number

of

lines, the

DIM

The DIM statement defines the number

is

variable as

the maximum possible subscript range for each dimension in the reference.

not dimensioned before it

given, DIM statements must allocate space before you refer to the arrays they dimension, since once

If

an

OPTION

an

array

is

BASE n statement

for arrays, it should precede the first DIM statement, or array reference.

DIM variable

In the example below, A

of

value

from 0 to 20. I

(integer

[,integer]

is

a single precision array with

is

an integer array with

three dimensional string array with

22

double precision array with

10

DEFINT I-N

20

DIM A (20), 1(12,13),

elements.

S$

of

elements in an array variable.

is

referenced, a default value

of

10

If

an

is

assumed

array

If

dimensioned, these dimensions cannot be changed.

is

used in the program to specify starting points

... ) [,variable

125

elements. DD#

(4,4,4), DD#

(21)

13

(integer

times

[,integer]

21

elements, indexed with a

14

(=

182)

is

a singly dimensioned

... ) ... ]

elements.

S$

is

a

6-5

Commands

and

Statements

DIR

The

DIR

command

the

files saved

drive

O.

DIR

EDIT

The

EDIT a selection changing. These and

Editing BASIC-80.

The

EDIT execution. be

entered by typing

BASIC-80.

displays

on

the

specified disk.

may

be used as a

[drive number]

command

of

editing

mode

It

can

is

used

subcommands

is entered automatically when a syntax

also

be

EDIT

the

names,

command

to

modify

and

entered when.entering text by typing

line

number.

number

If

no

or

single

that

facilitate character insertion, deletion

their uses

Refer

of

blocks,

drive

number

as a statement.

program

are

to

lines.

explained in

Chapter

and

is specified, the

error 3: Entering

length (in bytes)

default

In

this mode, you have Chapter

Control

3: Entering

prevents

A,

and

program

or

it

Editing

BASIC-SO

of

is

and

may

The

error.

EDIT line

period

numbeq

(.) is used

END

The

END

statement halts level. Files are closed, logical conclusion "BREAK optional

as

IN

the

END

The

program

10 INPUT A,B,C

20

D=(A + B + C)/3

30

PRINT

40

END

point

line

number"

last line

below contains

"THE

.

to

represent the last line changed, listed

program

but

variables

within

message,

of a program.

an

AVERAGE

execution

can

program

and

END

statement in line 40.

and

be examined.

text.

STOP

does

not

returns

acts like

close files.

OF";A;" + ";8;" + ";C;"EQUALS";D;"."

to

END

or

that

BASIC-80

may

be

END,

but

An

END

contained

command

used

at also prints a command

an

any

is

6-6

ERROR

The

ERROR

The

user-supplied integer expression will generate

its value, as shown in be greater that

does

will

print.

formation,

statement simulates the occurrence.

the

example listed below.

than 0 and

not

correspond

All errors

refer

to

Chapter

less can

than

to

a BASIC

be

trapped

4:

Error

or

equal

to

error

by

Handling.

255.

the

of

an

The

If

ERROR

message,

ON

ERROR

an

error

in

program

error

message

integer expression supplied

is

executed with a

"UNPRINTABLE

statement.

execution.

appropriate

number

ERROR"

For

further in-

to

must

BASIC-SO

ERROR expression

10

INPUT

12

IF

B=O

14

PRINT

20

END

RUN

? 40,0,17

DIVISION BY ZERO

Ok

EXIT

A,B,C

THEN ERROR

AlB

IN

12

11

Commands

and

Statements

The EXIT command terminates operation control to ISIS-II.

If

grams.

you EXIT without saving the current program, it will be lost.

EXIT

closes all open files, but does not automatically save pro-

of

the BASIC-80 interpreter and returns

FIELD

The FIELD statement random file buffers. When a random the specified random file buffer to associates the data with its position in the specified variable will access the proper string characters or numbers within the record stored in the random file buffer. The example below shows how FIELD used. For further information, refer to the BASIC-80 Disk

FIELD # file number,

number of characters

[,number of characters

The program below opens random file strings to insert into

10

OPEN

20

FIELD #1,30 AS A$

30

FOR 1=1 to 5

40

INPUT

50

LSET

A$ = Z$

60

PUT#1,1

70

NEXT I

80

CLOSE#1

90

END

"R"

Z$

is

used to allocate space within one

110 transaction occurs, data move to or from

or

from disk sectors. The FIELD statement

110

buffer

AS string variable

AS string variable] ...

:F1

:FILE.1 and asks for five 30-character

:Fl

:FILE.1.

,#1,

":F1

:FILE.1"

of

six

128-byte BASIC-80

so

that future references to the

Input/Output

section.

is

FOR-NEXT-STEP

The FOR-NEXT statement allows the execution number value A STEP taining the Program control returns to the A, and the routine

of

times. As shown in the example below,

is

incremented by the value given in the STEP instruction.

is

specified, the increment

FOR

instruction are executed until the NEXT instruction

is

1.

The instruction lines following the line con-

FOR instruction line, STEP

is

reentered. When variable A exceeds the TO expression, control

passes to the instruction line following the NEXT instruction line.

of

a given group

on

each iteration

is

added to the value of

of

lines a given

of

the routine,

If

no value for

is

encountered.

6-7

Commands

and

Statements

If

the

TO

expression

is

larger than the starting expression and the step expression negative then the loop will not execute. Similarly, if the TO expression is less than the starting expression and the execute. After the conclusion ed

in the loop.

STEP expression

of

the loop, variable A contains the first value not us-

is

positive, then the loop will not

BASIC-SO

is

Control cannot be passed to a statement within a

GO SUB

etc, but a GO

TO

can be used to jump out

FOR ... NEXT loops may be nested so long as each inner loop

loop~,

contained in all outer

If

possible, integer index variables should be used to speed execution. Double preci-

and they employ different index variables.

FOR ... NEXT loop with GO TO,

of

a FOR ... NEXT loop.

is

completely

sion index variables are not allowed.

FOR variable=expression TO expression [STEP expression] 10

FOR A = 1 TO 5

20

PRINT A * A,

30

NEXT A

40

END

RUN

1 4 9

16

25

GET

The GET statement reads the specified sector from the specified file into

If

random buffer. The file must be open for random access. specIfied, the sector number

is

sector

read. A GET without a sector number immediately after a file

the previous GET

or

of

return the first sector. The largest possible sector number mand

is

issued for a sector that has not yet been written, buffer contents are

is

undefined, and there

been

PUT

or

GET, the file will be extended.

no error message. However, if no greater record has ever

the sector number

PUT

is

incremented and this

is

2046.

If

128-

is

opened will

the GET com-

byte

is

not

GET

[I]

file number [,record number]

10

OPEN 20GET#3,1 30

FIELD 40

PRINT N$,SS$

"R" #3,

,#3, "F1

20

:PERSON"

AS N$, 9 AS

SS$

RUN

JONES, JOHN J.

Ok

517317010

GOSUB

The GOSUB statement transfers program control to the line number specified as an

is

argument. This line number

typically the first line number used several times during a program. The RETURN statement transfers control back to the first instruction that follows the last

GOSUB 10

20

30 100 110

line number

lNPUT

IF

GOTO

PRINT SQR(AO);SIN(A);TAN(A) RETURN

A

A>O

THEN GOSUB

10

100

ELSE PRINT

GOSUB statement executed.

"A

of

a subroutine that

MUST BE

is

>0"

6-8

BASIC-SO

Commands and Statements

GOTO

The GOTO (line number) statement transfers execution

to

current line

the line number specified. There

of

instruction lines from the

is

no provision for a return to the

branching point.

GOTO

line

numberl

GO

TO

line number

The GO TO in line 270 causes a jump to line 100.

250

IF 260 270 300 310

EOF(6) THEN

PRINT

GOTO

PRINT

END

"FILE

100

"FILE

300

STILL CONTAINS ";F$;"IS

OUTOF

DATA"

DATA."

IF-THEN-ELSE

The IF-THEN-ELSE statement evaluates the given logical expression and executes the THEN instruction if true, the

is

tion

optional; if it

is

left out, and the logical expression executed. Line numbers can be used in place as

GO TOs.

An

IF statement must always be on one line. IF statements may also be nested, as shown in the example below. In this example, an last unmatched

IF

expression THEN instruction [ELSE instruction]

THEN.

ELSE instruction if it

of

instructions and have the same effect

is

false. The ELSE instruc-

is

false, the next line

ELSE clause matches the

is

IF

S$

="

5

10

IF

S$ = "+"

20

GOT040

30

PRINT"lnvalid

40

END

"THEN

40

THEN A = A+B ELSE

S$"

IF

S$

=

"-"

THEN

A=A-B

ELSE

30

INPUT

The INPUT statement returns a prompt (question mark) and waits for the user enter data. String literals

or

numeric values may be expected, according to the type

of variable specified as an argument.

INPUT

If

a string expression follows INPUT and the question mark as the prompt. do not agree with the number

[quoted

string;] variable [,variable] ...

is

followed

If

the number

or

type

of

or

type of data items in the response

variables requested, BASIC-80 returns a

by a ";"

it

is

used in place

prompt to re-enter the line. Strings which are input need not be surrounded by

not

quotes as long as they do

contain commas (,). Leading and trailing blanks are

ignored in this mode.

10

INPUT A,B,C

20

PRINT(A+B+C)/5

30

END

RUN

?

40,2,18

12

Ok

to

of

6-9

Commands and Statements

KILL

BASIC-SO

The KILL command deletes files from disk storage,

the deleted file from the directory.

KILL filename

Once a file has been killed, it cannot be reopened.

and

removes all references to

LET

The LET statement left

of

an

equal sign not preceded by the word LET,

is

statement

implied. When assigning a literal value to a string variable, the value

must be enclosed in quotation marks.

[LET] variable = expression

10

LET

20

PRINT A

RUN

5

Ok

A=5

is

used to give a value to a variable.

If

a variable appears to the

BASIC-SO

assumes that a LET

LINE INPUT

The LINE INPUT statement reads the specified string variable. LINE INPUT does this in two ways: first, data may be read from the terminal and assigned; second, data may be read from a disk file and assigned.

an

entire line

of

data and assigns it as the value

of

When entering data from a terminal, the syntactic format is:

LINE

INPUT

This statement string

is

entered and a carriage return has been entered. Entering a Control-C abort LINE INPUT and return mand may then be used to re-enter the LINE

When entering data from a disk file, the syntactic format used

LINE

INPUT

This statement reads data from the specified disk file until a carriage return countered. The data

[string expression;] string variable

will

print the string expression as a prompt and will haIt until the

BASIC-SO

to the Command Mode. A CONT com-

INPUT statement.

is:

.file

number,string variable

is

assigned as a value for the specified string variable, and LINE

is

will

en-

INPUT skips over the encountered carriage return-line feed to point to the beginning

of the next file

I10~

the next string.

255

characters

If

no carriage return

of

data.

See

Chapter 5 for further information about disk

is

encountered, the statement returns

LIST

The LIST command prints the current program's text

lines are listed in sequential order. As shown below, the to display the entire program, all instruction lines up to or after a given line, or a

of

block

instruction lines within the program. The period may be used as

abbreviation for the last line which was changed, contained an error, or was listed.

to

the console. Instruction

LIST command may be used

an

6-10

LIST [line numberl-line numbeq line number-I line number-line number}

BASIC-SO

Commands

and

Statements

In the example below, LIST

including

40,

30; list 30- prints all lines after 30, including

and 50; LIST prints the entire program text.

10

PRINT CHR$(12)

20

INPUT

30

PRINT (A + B + C)/3

40

PRINT

50

END

LIST

30

PRINT(A+B+C)/3

LlST-30

10

PRINT CHR$(12)

20

INPUT

30

PRINT(A+B+C)/3 LIST 3030

PRINT 40

PRINT 50

END LIST 30

PRINT (A + B + C)/3 40

PRINT 50

END LIST 10

PRINT CHR$(12) 20

INPUT

30

PRINT 40

PRINT 50

END

30

30-50

A,B,C

(A+

A,B,C

(A

+ B + C)/3

30

B+C)/3

prints line

30

only; LIST -30 prints all lines up

30;

LIST 30-50 prints lines 30,

to

and

To

obtain a listing

mand, which

of

a file on a line printer

is

described on page 6-22.

or

other device, use the SAVE com-

LOAD

The LOAD command reads a file from disk and stores it current file. The string expression must be an

LOAD LOAD"

OK RUN

THIS PROGRAM PLOTS FUNCTION ON

LSET,

filename

:F1:

PLOT"

RSET

AN X-Y

ANY

USER-DEFINED

GRAPH.

ISIS-II filename.

in

memory, making it the

The LSET and RSET statements store the specified string expression into string space

that

has been allocated in a random file buffer by a FIELD statement. When

string variables are assigned to a random file buffer with the FIELD statement, they

6-11

Commands

and

Statements

BASIC-80

cannot later be assigned values with the LET statement. This

new

assigned

storage locations when given new values and this destroys the effect

is

because strings are

of the FIELD statement. Accordingly, the LSET and RSET statements must be used to assign new values. These commands may also be used with normal string statements.

If

the assigned string value in the FIELD statement, as needed. RSf:T right justifies the string in the same way.

the space reserved, the extra characters are ignored. with string variables that have not been fielded. the length of the receiving string

LSET

string

RSET string variable = string

10

A$

= "1

23456"

20

RSET

A$

=

30 40

50 RUN

CO

Ok

PRINT LSET PRINT

ABX

X

A$;

A$

A$;

=

is

shorter than the space reserved for the string variable

LSET left justifies the string, adding blanks (ASCII 20H)

If

the string

is

longer than

LSET and RSET may be used

Unlike normal string assignment,

is

not changed by an LSET or RSET assignment.

variable = string

"A

B"

expression

"X"

"C

0"

"X"

MERGE

The MERGE command reads a program from disk and combines it with the current

If

program without changing line numbers of either program.

the new program and

the current program have instruction lines with the same line numbers, the new in-

new

struction lines replace the current ones. The ASCII format. MERGE sets all variables and arrays to zero.

gram, the program will end. A given string expression must resolve to an

program must have been saved in

If

used within a pro-

ISIS-II

filename.

MERGE MERGE ":F4:

Ok

string

expression

EVAL.BAS"

NEW

The NEW command deletes the current program and clears all variables and arrays.

If

a program has not been saved and the NEW command

lost.

NEW

In the sample program below, the program has been deleted by the NEW command.

LIST command will not list it, or any program, until another

The peripheral device or entered line-by-line.

240 250 260 270 NEW Ok LIST Ok

PRINT

PRINT PRINT END

"end

of

program"

is

given, the program

is

read from a

is

6-12

BASIC-80

and

Statements

The NEXT statement

is

used with a previous FOR statement

to

end

an

iteration of a FOR-NEXT loop; when BASIC-SO encounters a NEXT statement, control passes back to the statement line containing the last

FOR statement.

If

no index variable specified, BASIC-SO increments the variable specified in the last FOR statement. Each NEXT can end more than one loop if the index variables used in each loop are given separated by commas.

The syntax

of

FOR

20

PRINT A * A;

30

NEXT A

40

END

RUN

1 4 9 16

Ok

A=1

25

is:

TO 5

NULL

The NULL command specifies the number

printed line, following the carriage return. This feature minals that require a certain number timing.

of

null characters printed

is

used with hard copy ter-

of

null characters that set carriage return

at

the end of a

is

NULL

ON

number

ERROR

of

null

GOTO

characters

to

be

transmitted

The ON ERROR OOTO statement transfers program control to the specified line

or

number when error conditions occur

within a program. The

is

function

set to the applicable line number.

The instruction line ERROR OOTO, ERROR OOTO 0 before a

RESUME) the proper error message prints and execution halts

ERR

function

ON ERROR OOTO 0 removes the effect

so

that

errors cause messages to print and halt execution.

is

executed within

an ERROR instruction simulates an error

is

set to the applicable error code and the ERL

of

any previous ON

If

an

error-handling routine (after an error but

ON

immediately.

If

an error occurs in

before a

RESUME, the ON ERROR OOTO has no effect. This means that if an ON ERROR OOTO an intervening

an

error routine, after an ON ERROR OOTO branch and

is

in effect, and two errors (or ERROR commands) occur without

RESUME, the second error prints an error message and halt

execution.

ON ERROR GOTO 10

ON ERROR GOTO

20

ERROR

11

line

200

number

200

PRINT

210

RESUME NEXT

"ERROR"

ERR

"AT

LINE"

ERL

6-13

Commands

and

Statements

ON ... GOSUB

The

ON

... GOSUB statement transfers subroutines.The line numbers tially, separated by commas. third line

number

ON

expression

10

INPUT A

20

ON

following GOSUB.

GOSUB line

A GOSUB 200,300

program

of

the first lines

If

the expression evaluates

number

of

[,Iine number] ...

control to one

these subroutines follow sequen-

to

or

one

of

a set

3, control transfers to the

BASIC-SO

of

ON ...

The ON ... numbers. number following the line containing the evaluates

GOTO

The

expression X

to

3, control transfers

expression

ON 10

INPUT A

20

ON

A GOTO

statement transfers program control to one

is

evaluated

to

the third line number following GOSUB.

GOTO line

500,510,520

number

OPEN

The

OPEN associates a file number from 1 Random

and

an I, tactic

format and less the file in

statement makes

110

files are specified by

sequential

below.

than

or

110

transactions.

output

The

equal to 6,

an

ISIS-II file available

to

6 with

an

files are specified by

file number

is

preceded by a

or

one

of

a set

of

line

and

control

ON

...

[,Iine number] ...

the

R, sequential input files are specified by

is

an

is

transferred to the

GOTO

instruction.

file. File type can be I,

an

0,

integer expression greater

"#"

sign, and

If

the expression

to

BASIC.

as shown in the syn-

is

used

to

"nth"

It

0,

or

than

reference

line

also

R.

0

6-14

Only six files may be open and

MERGE

they are executed.

BASIC-SO buffers files, so if :CI: the first line

OPEN type, [I] file number, filename

where type the file SYSLIB

OPEN

all require a file, so a maximum

of

console input.

is

a string expression equal to

is

opened as a

"R"

,#4,

"SYSLlB"

at

one time.

random

Note

that

SAVE, LOAD, DSKF; DIR

of

five files may be open before

is

opened for input, BASIC-SO will wait for

"0",

"I"

or

"R".

In the example below,

I/O

file, with number 4.

BASIC-SO Commands and Statements

The example below shows a typical use of OPEN in an 110 program.See Chapter 5 for further details

10

OPEN

20

GET

30

FIELD #3,20 AS N$, 9 AS

40

PRINT N$,SS$

RUN

Ok

of

"R"

#3,1

JONES,

disk random 110.

,#3, "F1

JOHN

:PERSON"

SS$

J.

517317010

OPTION BASE

The OPTION BASE command

specifying

an

argument

of

OPTION BASE should precede all DIM statements and array references.

1

is

TION BASE

OPTION BASE

not specified, 0

011

is

used to begin indexing

0 or

1,

you can begin all arrays

is

the default value.

of

arrays

at 0 or

at

1.

1 or

If

present,

If

O.

By

OP-

OUT

The OUT statement writes the specified value an integer expression in the range 0 to 255.

OUT

port

number,

This example rings the bell

OUTOF6H, 7

expression

on

Intellec development systems using the RS-232 port.

to

the specified 110 port. The value

is

POKE

The POKE statement places the specified value into the memory location specified.

is

The specified value

POKE

can also accept hexadecimal and octal arguments, even though octal and hex constants over 32767 (decimal) are interpreted by does this by adding 65536

an expression that must round to an integer in the range 0-255.

to

such arguments.

BASIC-80

as

negative numbers.

It

POKE POKE OFFFFH, 0

POKE POKE 1777770,0 POKE

location,

65535,0

-1,0

expression

The instructions above set the top byte of memory to 0 in system having 64K command to reserve free memory. A BASIC

or

other software to fail.

of

memory. Before using POKE, you should use the CLEAR

POKE into BASIC

an

Intellec development

or

system code may cause

6-15

Commands and Statements

PRINT

The

PRINT console, or to any (");

variables and expressions need no quotation marks. You can print data

inserted following

of

ning starts ment, the next printing starts prints one blank line. A

the next 14-column zone.

at

the next column.

PRINT

10

INPUT

20

PRINT

30

END

RUN

? A

string YOUR STRING Ok

statement returns the value

of

expressions

or

the text

of

ISIS-II file. Literal strings must be enclosed in quotation marks

to

any ISIS-II file by specifying a file number.

an

expression to be printed, the next printing starts

"?"

[II

filenumber,][[

"A

string";

"YOUR

IS

If

a semicolon (;)

If

no punctuation

at

the beginning

is

used at the end

is

inserted, the next printing

of

the next line. PRINT by itself

entered after a line number means PRINT.

expression],

X$

STRING

A string

IS

";X$

I;] ...

If

a comma (,)

of

the PRINT state-

strings to the

is

at

the begin-

BASIC-SO

PRINT USING

The PRINT USING statement specifies particular formats to print strings numbers. The format string may include more any literal character format

of

PRINT

[#

that

is

not a

PRINT

USING

file number,] USING format string; expression

is:

than

one field, and may also include

USING formatting character. The syntactic

[,

expression] ...

in which the format string specifies spacing and additional characters (such as asterisks and dollar signs) when used with numeric fields, and which specify portions of

the given string when used with string fields. Each expression same format. The optional file number specifies the number Chapter 5 for details

of

sequential disk file 110.

is

printed with the

of

an

open file. See

String Fields

There are two formatting choices when using "!"

specifies that the first character

"\

n spaces

\"

specifies

that

of

the first 2+N characters are printed.

are used without spaces, two characters are printed.

If

the string field has more characters than the format string, the balance are ignored; if there are fewer characters than specified, spaces are printed to fill out the field. Here are examples

of

the string field formats:

PRINT

USING with string fields:

each specified string

is

printed.

If

the backslashes

or

6-16

10

X$="ONE"

20

Y$="TWO"

30

PRINT USING

40

PRINT

RUN OT ONE TWO Ok

"!";

X$;

USING" \ \";

Y$

X$;

Y$

BASIC-80

Commands

and

Statements

As can be seen, each string. characters from X$ Y$="SEVEN",

ONE SEVE

and if

X$="SEVEN"

SEVEEIGH

PRINT

USING

"!"

USING \ 2 spaces \ prints a string consisting

(3

plus a space) and four from

the result printed when line

and

Y$="EIGHT",

prints a string consisting of the first letters

Y$

(also 3 plus a space).

40

is

executed would be:

the results of line 40 would be:

Numeric fields

The

PRINT

signs, plus or minus signs, exponentiation, asterisk fills, or insertion

of

Each

I The number

USING formatting characters specify right justification, leading dollar

the BASIC-80 format characters

or

be printed

sharp sign

is

too small to fill all

(H)

is

explained in the following section.

indicates the position of digits.

of

the digit positions specified

If

the decimal point, leading spaces print to fill the entire field. An integer can print as up to five digits, single precision floating-point up

to

and double precision floating-point up to fifteen digits.

of

four

If

of

commas.

the number to

to

the left

of

seven digits,

• The decimal point can be inserted in any position in the field. specifies whether it

+ The plus sign

that

a digit follows the decimal point, the digit always prints,

is

a 0 or another number. Numbers are rounded as necessary.

PRINT USING

41.29 PRINT USING

0.71

(+)

"IH.II";

"IH.HI";

is

used

41.287

71/100

at

the beginning or end of the field characters. Insertion of this character prints a plus or minus sign, depending on the sign

of

the number,

at

the beginning or end of the number,

respectively. The minus sign

printing space number

of

is

printed.

is

PRINT

+4.89

PRINT USING

5.8-

(-)

is

used

at

the right

of

the format character field to force

a trailing minus sign if the number

If

neither

printed with a leading

USING"

-2.67

"IH.H-";

96.2

(+)

+H.IH";

or

(-)

is

included in the format, a negative

(-).

4.89; -2.6689

-5.8;

96.2

is

negative.

If

the format

of

format

it is positive, a

**

The double asterisk (**) fills any leading blank spaces in the number format with asterisks. This symbol also specifies positions for two more digits.

PRINT USING "**HH.H"; 4.8; ***4.8 *243.3

243.3

6-17

Commands

and

Statements

BASIC-80

$$ The double dollar sign ($$) adds a single dollar sign to the immediate left

of

the number being formatted.

PRINT USING "$$###.##"; -48.28; 364.90

-$48.28 $364.90

($$)

specifies space for two additional characters, but the $ added takes up one posi-

tion. The exponential format cannot be used with

The double asterisk-dollar sign (**$) returns the results

**$

($$) format characters. Exponential format cannot be used;

three additional digit positions, one

is

The comma (,)

of

left

every third digit on the left

placed to the left of a decimal point to print a comma to the

specifies another digit position. A comma to the right

($$).

of

both the (**) and

"**$"

allows for

of

which

is

the dollar sign.

of

the decimal point. The comma also

of

the decimal point

prints in that position. The comma cannot be used with exponentiation.

PRINT USING

92,114.84

tttt Four carat signs (or vertical arrows) specifying exponentation. The carats

"11###11,.##";

92114.84

or

or arrdws are placed after the numeric format characters. Any decimal point

AM

format may be used. The significant digits are left justified, and the exponent is

adjusted. The comma and floating ($) cannot be used when exponentiation

is

specified.

070

The percent format has been encountered. by a

(070)

field, the rounded number

(070)

character indicates that a number larger than the given

BASIC-80 returns the number itself preceded

sign; or, if rounding the number causes it

is

printed, preceded by a

to

exceed the specified

(070)

sign. of specified digits exceeds 24, an ILLEGAL FUNCTION CALL error results.

PRINT USING

40.48%

766784.00%

"11#.1111";

40.48;

99997.00

766784;

99997

PRUN

The

PRUN

address

command starts execution

of

the program

is

an integer argument. The program must be saved in

of

a program stored in PROM. The

ASCII, and followed by a (Control-Z).

PRUN

address

PUT

The

PUT

statement transfers to the specified disk 'sector. The when the random file was opened and the sector the data goes to.

is

number written to.

specified, and no

If

data have been written to the disk, the number written increments, and the next sector exceed 2048.

data

from the previously formatted random file buffer

PUT

statement requires the file number assigned

data

have been written to the disk, the first disk sector

of

is

written to. The sector number may not

If

the number

If

no sector

is

the last sector

6-18

BASIC-SO Commands and Statements

PUT

file

number,

[sector

number]

10 OPEN

20

FIELD 10 AS A$

30

INPUT

40

PUT 1,1

50

CLOSE

60

STOP

RUN

"A

?

Ok

"R",

A$

1

STRING"

1,

":F1:FILE.1"

RANDOMIZE

The RANDOMIZE statement prompts the user for a

If

the random number function RND.

the RANDOMIZE command

within a program, the same sequence of random numbers will repeat each time any

is

program

If

the optional expression is included, its value becomes the

is

issued.

run.

RANDOMIZE

10

RANDOMIZE

20

A=

RND

30

IF A < .5

40

IF A

>=

.5 RUN Random TAILS Ok

number

[(expression)]

THEN

seed

PRINT

"HEADS"

"TAILS"

(0-65529)?

123

new

random number seed for

is

new

seed and no prompt

not

given

READ

The READ statement sequentially assigns values found in the accompanying DATA

If

statements to the variables specified. available,

DATA

error message will be printed.

an

OUT

OF available to be read, the next READ statement will assign the next datum to the specified variable. The READ pointer may be reset to the first item statement with the as the type

of

DATA

20

READ A, B,C,

30

PRINT A;

40

READ

50

PRINT RUN 246 81012 Ok

RESTORE command. Any type

the DATA

variable

2,4,6,8,10,12,14,16,18,20

D,E,F

D;E;F

is

[,variable]

B;C

appropriate for the type

...

more DATA fields are read than are

If

there

is

still data

of

any DATA

of

variable may be read as long

of

variable.

6-19

Commands

and

Statements

REM

BASIC-SO

The REM statement instruction line that begins with REM following its line number program control passes to the next line. Within a remark, : (colon)

is

used to insert commentary remarks into program text. Any

is

passed over, and

is

simply another

character, not a statement separator.

REM

10 REM THIS PROGRAM FINDS 20

REM OF

30

INPUT

40

PRINT

50

END

THREE A,B,C (A+

B+C)/3

NUMBERS

THE

AVERAGE

RENAME

The RENAME command changes the name Only the directory reference (accessed with the DIR command) grams reference the old filename, a FILE

RENAME

"old

filename"

TO

of

the specified file to the new filename.

is

altered; if pro-

NOT FOUND error message will result.

"new

filename"

RENUM

The RENUM command resequences line numbers in a program, whether they ap-

at

pear

the beginning specify up to three optional arguments: the first be renumbered, the second the third number

is

the increment between lines.

of

the first line to be renumbered

renumbered, and the increment

of

a line or as the object

is

the old number

is

assumed to be

of

a OOTO statement. You can

is

the new number

of

the first line to be renumbered, and

If

you specify no arguments, the new

is

assumed to be

of

the first line to

10,

all lines are

10.

REN UM 20

40 15 RANDOMIZE

5 PRINT CHR$(12) 52 58 RENUM LIST 10 20 30 40 50 60A2=

[new

number][,[old

INPUT PRINT

A1 = A*RND A2 = INT(A1)

PRINT CHR$(12) RANDOMIZE INPUT PRINT A1 = A*RND

A

"NEW:";

A "NEW:";

INT(A1)

number][,increment]]

A

RESTORE

The RESTORE statement resets the READ pointer to the first DATA statement within program text. The DATA statements can then be reread. A line number can be specified following next.

RESTORE; if included, data on the specified line will be read

6-20

BASIC-SO Commands

and

Statements

RESTORE

10

DATA 48,49,51,53,58

20

DATA 104,108,116,132,164,5000,5000

30

READA,B

560

IF

570

RESTORE

580

READA,B

[line

number]

B<5000 THEN

30

RESUME

The RESUME statement restarts program execution after

and handled. Program execution begins specified, execution resumes ment

RESUME NEXT causes execution

at

the statement where the error occurred. The state-

statement.

RESUME

[line

numberlNEXT]

at

the line specified;

at

the statement following the erroneous

an

error has been detected

or

if no line number

is

140

ON ERROR GOTO

200

PRINT

210

PRINT

220

RESUME NEXT

"ERROR";ERR;"AT

200

LlNE";ERL;"."

RETURN

The RETURN statement control back to the instruction line immediately following the last GOSUB statement executed.

RETURN

50

GOSUB

60

PRINT

200 210

220

230 240

IF IF

A=11

PRINT PRINT

200

"TYPE

A>100 THEN PRINT

A<=O THEN PRINT

(B* B1)

"YOUR

is

placed

at

NUMBER"

"OUT

"A

the end

MUST BE

OF

IS

of

";A;

a subroutine, and transfers program

RANGE"

>0"

GOSUB

or

ON

...

6-21

Commands

and

Statements

RUN

BASIC-SO

The RUN command starts the execution enter

RUN

alone, it executes the current program starting

If

you enter RUN followed by a line number, it executes the current program start-

ing

at

the specified line number. representing a file name, it looks for a file with into memory, latter form, an Files can be left open only if the command erases all variables before executing the program.

RUN

The RUN together.

line number RUN

This feature can fit into memory as one large program. variables to zero, however, so if you want to pass some variables to the next program,

print details) during execution subsequent programs.

In the example below, the (tC) character halts program execution.

and

executes the program starting

"F"

may be added

program

[line

numberlstring

command

The

form

of

may

the

RUN

expression [,F]]

also be used as a program statement to chain programs

command

"filename"

is

especially useful for the execution

them

out

to a buffer

of

file (see the section

the first program. Then read them, when needed, into

of

a program or a set

If

you enter RUN followed by a string variable

that

name

at

the lowest line number. With the

to

leave files open. Otherwise, they are closed.

was saved in non-ASCII format.

that performs this function is:

of

programs

The

RUN command initializes all

on

of

programs.

at

the lowest line number.

on

disk, loads its contents

The

that

are larger

"Random

Disk

110"

If

you

RUN

than

for

LIST

10

INPUT A,B,C

20

PRINT (A+B+C+)/3

30

PRINT"NEXT SERIES"

40

PRINT: PRINT: PRINT

50

GOTO 10

60

END

RUN

?41,12,6

19.6

NEXT SERIES

6-22

?

tC

(This control character interrupts execution)

BREAK

IN

10

OK

RUN

30

NEXT SERIES ?

SAVE

The SAVE command stores the current program The addition with the specified name exists, it will be replaced by the new file. Any valid file name may be used. You can use a string expression that resolves filename. printer. Refer to the filenames.

of a comma

For

example, SAVE

and

an

A saves

":LP:",

the

A will list the current program

ISIS-II User's Guide for more information

on

disk with the specified filename.

file in ASCII format. Note

on

ISIS- II device

that

to

an ISIS-II

on

if a file ISIS-II

the line

BASIC-80

Commands

and

Statements

SAVE string 10

INPUT

20

PRINT (A + B +

30

END SAVE OK RUN

"AVER"

expression

A,B,C

"AVER"

[,A]

C)/3

? 5,8,2

5

Ok

STOP

The STOP statement halts program execution and prints a BREAK IN (line number) message. Following this, STOP, program variables may be changed or printed, and, if the program changed, execution may be resumed with the also halts execution, closes any open file.

STOP

BASIC-80

but

does not print a BREAK

is

in the command mode. After execution

of

is

not

CONT command. The END statement

IN

(line number) message, and

a

320

PRINT

330

STOP RUN END OF PROGRAM

BREAK

Ok

IN

"END

330

OF PROGRAM"

SWAP

The SWAP statement exchanges the values assigned to any two variables or string

that

variables, provided

SWAP variable1, variable2

110

IF

X>Y THEN SWAP X,Y

120

PRINT

TRON,

"NEW

TROFF

they are

VALUE

of

the same type.

OF X IS";X;""AND Y IS

NOW";Y

The two program tracing commands, TRON

and

TROFF, respectively enable and

disable the trace function in program execution. When enabled, the number of each

is

line

printed as it

is

executed, enclosed in square brackets. These commands can

also be used within programs to selectively enable and disable tracing.

6-23

Commands

and

Statements

WAIT

TRON TROFF

10

INPUT

20

PRINT(A+B+C)/3

30

END TRON OK RUN [10]42, [20]45 [30]

OK TROFF OK

RUN

30,

18,12

20 Ok

48,

A,B,C

45

BASIC-80

The WAIT statement instructs BASIC-80 to monitor incoming bytes from a

is

specified port. These bytes are tested with a mask byte, which sion in the range bits

of

the comparison byte, also

I comparison byte

halted until the two sets

is

status

exclusive ORed with the comparison byte and the result

mask byte. Execution halts until a non-zero value

WAIT

0 to 255. The resulting bits are compared with the corresponding

an

integer expression in the range or 0 to 255.

is

port

not specified, the default value

of

bits differ. When the WAIT command

number,

mask

byte,[comparison

is

O.

Execution

is

obtained.

byte]

an integer expres-

of

program text

is

given, the port

is

ANDed with the

WIDTH

The WIDTH command adjusts the width specified value, which

is

WIDTH

72.

WIDTH 10

CALIFORNIA" 20 30 40 50 60

RUN ACTION, OHIO; WEAVERTON, VERMONT; HOLLOWAY, CALIFORNIA ACTION, OHIO; AVERTON, VERMON

T;

LlFORNIA

Ok

expression

A$

=

PRINT WIDTH

PRINT

WIDTH

END

HOLLOWAY,CA

is

"ACTION,

A$

15

A$

72

WE

an expression in the range

OHIO; WEAVERTON, VERMONT; HOLLOWAY,

of

the lines printed

15

to 255. The default value for

at

the console to the

If

the

is

6-24

ABS

CHAPTER 7

FUNCTIONS

The ABS function returns the absolute value absolute value

ABS(expression)

10

20 30 40 RUN

?5

10

Ok RUN

?

-5

10 Ok

of

an

expression

INPUT A A = ABS(A *2) PRINT A END

is

its numeric value with a positive sign.

Ase

The ASC function returns the ASCII code string.

of

the specified expression. The

the first character

of

the specified

ASC(string PRINT ASC

48

expression)

("0"),

ASC("AB")

65

ATN

The ATN function returns the arctangent value result, given in radians, single precision,

ATN(expression) 10

INPUT A

20

B = ATN(A)

30

PRINT B

40

END

RUN

?5

1.373401 Ok

but

is

between

the argument may be any numeric type.

-PI/2

and

PI/2.

of

the specified expression. The

The calculation

is

performed in

7-1

Functions

BASIC-80

COBl

The CDBL(X) function changes the type

floating-point representation. In this format, calculations are accurate to places, compared to an accuracy

of

expression (X) into double precision

16

decimal

7 decimal places in single precision floating-

point representation.

Many fractions (such as

1/3

and .1) cannot be precisely represented with either single or double precision floating point, due to BASIC-80's internal numeric representation.

CDBL(expression)

10

A#=1/3

208#=CDBL(1)/3 30

PRINT A#,B#

40

END

RUN

.333333343267441

Ok

.333333333333333

CHR$

The CHR$ function evaluates the expression to an integer and returns the equivalent ASCII character. The expression must evaluate to an integer between 0 and 255.

CHR$

(expression)

In the program below, the CHR$(12) command generates a form feed in line 110.

110

PRINT CHR$(12)

120

PRINT 130 140 150

PRINT

"TABLE A;8;C;D;E

2-5:

COMMONLY

USED

CONSTANTS"

CINT

The CINT(X) function rounds the expression into an integer value and returns that

value.

If

the expression

result.

NOTE: The FIX and INT functions also convert to integer Formats. FIX

truncates; INT truncates to

CINT(expression)

This program averages three numeric values and returns an integer result:

10

INPUT

20

PRINT

30

END

RUN

?

45,

24,77

49

is

less than -32768

A,B,C

(CINT((A+

an

integer argument.

8+C)/3))

or

greater than + 32767 then overflow will

7-2

BASIC-80

Functions

cos

The COS function returns the cosine value given in radians.

COS(expression)

10

INPUT

20

B = COS (A)

30

PRINT B

40

END

RUN

The

calculation

A

is

performed

of

the specified expression. The input

in

single precision.

?5

.2836621

Ok

CSNG

The CSNG(X) function changes the type

point representation. In this format, calculations are accurate places, compared floating-point representation.

Performing calculations in single precision not

be as accurate.

CSNG(expression)

to

an

accuracy

of

expression into single-precision floating-

of

sixteen decimal places in double precision

is

faster than

in

double precision

to

seven decimal

but

is

may

10 A# =

20

RUN

.1666667

1.00/3.00

PRINT

CSNG

(A#)

12,

A#/2

.1666666666666667

CVI CVS

eve

The CVI, CVS, two character string into ternal integer representation.

sion, and fashion.

These functions are used to retrieve numeric values from a random file buffer field,

and are the reverse

CVx(string

AO/o

B!=2

C#=3

0$ = MKI$(AO/o) A

% = CVI

B! = CVS (MIO$(O$, 3))

C# = CVO (MIO$(O$, 7))

PRINT A,

and

CVD functions convert strings into numbers. CVI converts a

CVD converts

of

MKI$, MKS$, and MKD$.

expression)

= 1

+ MKS$(B!) + MKD$(C#)

(0$)

B!,

C#

1 2 3

an

integer by simply moving the two characters into the in-

CVS converts a four character string

an

eight character string into double precision in a similar

to

single preci-

7-3

Functions

BASIC-SO

DSKF

The DSKF function returns the number specified disk. The examples below signify free space on disk

DSKF

PRINT DSKF (1) 50 OK

1.

(drive

number)

EOF

The

EOF

function detects when the end

tial

data

file.

If

there are no more

At

TRUE.

any other time,

open, an error results.

EOF

(file

number)

10

OPEN

20

IF EOF(1) THEN

30

LINE INPUT

40

PRINT

50

GOT020

60

END

"1",1,

A$

"[F1:

#1,

EOF

PROGRAM]

60

A$

of

data

will return 0, indicating FALSE.

of

128-byte sectors

that

there are

the file

in

is

reached when reading a sequen-

the file, EOF returns a -1, indicating

50*

that

128,

are free

or

6.4 kilobytes

If

the file

on

is

the

of

not

ERL

The

ERL

function returns the number

It

is

normally used after an ON ERROR GOTO ... error trapping routine.

ERL

of

the line in which the last error took place.

The program below uses the error-trapping instruction in line description in line code number error code

11:

10

ON ERROR GOTO

20

A =

30

END

40

PRINT

50

RESUME NEXT RUN PROGRAM ENDS IN LINE Ok

40. This line also contains the function ERR, which displays the

of

the error. In this example the error

40

is

division by 0, which has the

1/0

"PROGRAM

ENDS IN

20

WITH ERROR

LlNE"ERL"WITH

11

ERROR"ERR

ERR

The

ERR

function returns the code number

gram execution.

of

the last error encountered during pro-

10

to print the error

7-4

ERR

BASIC-SO

Functions

The following program asks for a divisor

trapping routine in lines stopping the execution:

10

ON ERROR GOTO

20

INPUT

30

Z =

40

PRINT

50

GOTO

60

IF ERR

70

PRINT

80

RESUME

90

ON ERROR GOTO 0

100

RUN WHAT ?045,9 QUOTIENT WHAT

"WHAT

X/Y

"QUOTIENT

20

<>

"YOU

END

ARE THE NUMBERS TO DIVIDE?

ARE THE NUMBERS TO DIVIDE? 11,0

60-90 to prevent division by zero (which has code 11) from

60

ARE THE NUMBERS TO DIVIDE";X,Y

IS";Z

11

20

IS

OR ERL

CAN'T

5

<>

30

THEN

HAVE A DIVISOR OF ZERO!"

? 11,0

YOU

CAN'T

WHAT

HAVE A DIVISOR OF ZERO!

ARE THE NUMBERS TO DIVIDE?

?

EXP

The function The specified value must be less than 88.7, performed in single precision.

EXP(expression) 10

20 30 40

RUN ?5

148.4131

OK

?

EXP

returns the result

INPUT A B = EXP(A) PRINT B END

of

raising e (2.71828) to the specified power.

and

a dividend, and uses the error-

90

or

overflow occurs. The calculation

is

FIX

The FIX function truncates numbers with decimal fractions to their integer value.

FIX

(number)

PRINT FIX (41.99999) 41

Ok·

FRE

The

FRE

function returns the number argument (X) returns the number

FRE (X)I(X$) PRINT

22490

is

given.

FRE(X)

Ok

If

you give a string variable as a dummy argument (X$),

of

free bytes in string storage space.

of

bytes

of

memory left when the dummy

FRE

7-5

Functions

HEXS

The

HEX$(X) function returns a string hexadecimal value to

32767,

handle arguments in

but

HEX$

(expression)

of

the integer argument. In BASIC-SO, integers are from -3276S

SOSO/SOS5

both

memory

ranges correctly.

of

hexadecimal digits which represents the

addresses go from 0 to 65535 decimal.

HEX$

BASIC-80

will

PRINT HEX$

Returns:

FFFF FFFF HEX$ 10

PRINT

20

PRINT "NEEDED FOR YOUR PROGRAM,

30

PRINT

40

INPUT A

50

A$

60

PRINT

INP

The

INP

function returns the value

expression.

INP

50

IF

60

IF

(-1),

HEX$

(65535)

(expression)

"TYPE

THE NUMBER

= H EX$(A)

"YOU'LL

The

expression must be

(expression)

INP(A) = INP(A) = 7 THEN PRINT

NEED

12

THEN PRINT

OF

BYTES OF

";

A$;

"BYTES"

of

a byte from the

an

integer expression in the range 0-255.

"FORM

"BELL"

FEED"

SPACE"

IN

DECIMAL:"

input

port

specified by the

7-6

INPUTS

The

INPUT$ quential file. In the example below you the console into sequential file #2. the first INPUT$ treats Carriage

INPUT$ (characters,

10 20 30 40

RUN 1234567890 1234567890

function reads

10

characters

OPEN PRINT CLOSE#2 END

"1",

IN

to

of

file #2, and CLOSE concludes the reading

Return

filenumber)

#2,

":CI:"

PUT$ (10,2)

(CR)

a specified number

The

like any other character.

of

characters from a specified se-

can

type in any ten

:CI: specifies console input. Line 20 prints

or

more characters from

of

the

data.

BASIC-80

Functions

INSTR

The INSTR function searches for the first occurrence

and

within the first given string,

returns the first position of the second string as an

ordinal number. The optional argument, an expression I greater than

at

255, starts the search conditions: if I not

be found in the first string,

INSTR ([I,] 10

20 30 40 50

RUN

1

13 Ok

is

greater than the length of the first string, if the second string can-

string

A$ = "RANDOM

B$ = "R" PRINT INSTR(A$, B$) PRINT INSTR(3,A$, B$) END

I characters. The INSTR function returns a 0 under three

or

if the first string contains no characters.

expression,

NUMBER

string

expression)

SUBROUTINE"

of

the second given string

0

and

less than

INT

The INT function returns the largest integer value less than or equal to the specified expression. The sign

expression.

of

the returned value

is

the same as the sign

of

the specified

INT(expression) 10 INPUT A

20

B = INT(A)

30

PRINT A

40

END

RUN

? 18.0427

18 OK

RUN

? -234.98

-235

LEFT$

The string function .LEFT$(X$,I) evaluates the string characters. I

LEFT$

10 20 30 40 RUN WHITE, SMITH, JONES, BLACK, GREEN WHITE, SMITH Ok

is

an integer in the range 0-255.

(string

X$ = "WHITE, Y$

= LEFT$(X$,11)

PRINTX$ PRINTY$

expression,

SMITH, JONES, BLACK,

expression)

X$

and returns the leftmost I

GREEN"

7-7

Functions

BASIC-80

LEN

The string function LEN(X$) returns the length, in number X$. All characters are counted, including non-printing characters

LEN (string

10

X$ = "JOHN

20

PRINT LEN(X$)

30

END

RUN 13 Ok

expression)

J.

JONES"

of

characters,

and

of

blanks.

string

LOC

The LOC function has two uses. When used with a random file, LOC returns the current sector number. The current sector is defined as the last sector or

written. with a sequential file, last

OPEN

If

no sectors have been read

LOC returns the number

statement was executed

LOC (file number)

10

OPEN

20

GET #3,44

30

PRINT LOC

40

END

RUN 44 Ok

"R",

#3,

(3)

:F1

:RANDOM

on

or

written, LOC returns to

of

sectors read or written to since the

that

file.

that

was read

O.

When used

LOF

The

LOF

function returns the number

with a sequential file, it returns the number

of

sectors in a random file. When LOF

of

the file.

LOF (file PRINT LOF(4)

33

number)

LOG

The LOG function returns the natural logarithm performed in single precision.

LOG(expression)

10

INPUT A

20

B =

LOG

(A)

30

PRINT A

40

END

RUN

?

2488

7.81924 Ok

data sectors

of

the argument. The calculation

(128

bytes per sector) in

is

used

is

7-8

BASIC-SO

Functions

MID$

The MID$(X$,1. [,J]) function examines string

characters starting

is

specified, J characters are returned, starting

LEN(X$), the MID$ function returns the null string. the number

of

rest

The MID$ (X$, statement. Employed in this context, it will replace the characters ning X$

are replaced.

displayed. The length

of

the

string.

MID$(string expression, expression [,expression])

10

X$ = "JOHN

20

PRINT MID$(X$,10,3)

30

PRINT MID$(X$,9)

40

END

RUN ONE JONES

Ok

at

position I with the string given

10

A$ = "ABCDEF"

20

B$ = "XXYYZZ"

30

MID$(A$,2,4) =

40

PRINT

50

END RUN AXXYYF

Ok

at

pointer

characters in X$ to the right

1.

[,J]) function may also appear on the left side

If

I

of

A$

1. I and

J.

JONES"

is

greater then LEN(X$) , an illegal function call error

X$

is

never changed.

B$

J are integers in the range 1-255.

of

on

the right.

X$

and

returns the rightmost

at

position

I or

is

not specified, MID$ returns the

If

J is specified, J characters

1.

If

argument J

If

argument J

If

I

is

greater

is

greater

of

an assignment

of

string X$ begin-

than than

of

is

MKI$ MKS$ MKD$

The three functions MKI$, MKS$, and MKD$ convert

numerical values into two-, four-, convert value; and MKD$

These functions are used to place numeric values into fields See Chapter 5 for discussion

an

integer value; MKS$

is

used

to

MKI$ (integer) MKS$ (single-precision value)

MKD$ (double-precision value)

or

eight-byte strings, respectively. MKI$

is

used

to

convert a single-precision floating-poinf

convert a double-precision floating-point value.

of

MKI$, MKD$, and MKS$

OCT$

The

aCTS

integer argument.

function returns a string

The

expression

OCT$

(expression)

10

PRINT "TYPE DECIMAL INTEGER

20

INPUT A

30

A$

= OCT$(A)

40

PRINT

A,"EQUALS,"A$,"

of

is

rounded to an integer before conversion.

octal digits which represent the value

TO

BE

CONVERTED."

IN

OCTAL."

data

represented as

is

used

of

random file buffers.

of

to

the

7-9

Functions

BASIC-80

PEEK

The PEEK function reads a single byte from memory corresponding

PEEK (expression) PRINT PEEK(OFABH)

200

POKE statement writes a byte into a specified memory location.

P~S

The POS function returns the position

is

The argument I

POS (integer) 10

INPUT

20

PRINT A$;

30

IF POS(1) >

40

PRINT RUN ?AAAAA AAAAA OK RUN ?AAAAAAAAAAA AAAAAAAAAAA HAS Ok

a dummy argument. The leftmost position

A$

10

HAS

JUST

"HAS

JUST

BEEN

THEN

JUST

INPUT

PRINT

BEEN

of

INPUT"

INPUT

the cursor after the last PRINT statement.

at

the location specified. The

is

1.

7-10

RIGHTS

The RIGHT$ function returns the rightmost I characters exceeds the length

RIGHT$ (string,integer)

10

A$ = "JOHN 20

X$

30

PRINT RUN

JONES

J. Ok

of

X$, the entire string

J.

JONES"

= RIGHT$(A$,8)

X$

is

the result.

If

of

string X$.

I

is

0,

a null string results.

If

I equals

RND

The RND function returns a single precision random number between 0 and

sequence produced (such as in games) use

RND

is

identical every time a program

is

run.

RANDOMIZE to prompt the user for a seed.

If

this

is

undesirable

1.

or

The

BASIC-SO

Functions

SGN

The SON function returns the sign greater than 0, SON returns sion

is

less

than

0, SON returns -1.

SGN(expression) 10

INPUT A

20

LET B = 3.14159*SGN(A)

30

PRINT B

40

END

RUN

?

44

3.14159

OK

RUN

?

-12

-3.14159

OK

RUN

1.

of

the specified expression.

If

the expression

?O

o

Ok

SIN

The SIN function returns the sine value radians. The calculation

SIN (expression)

is

performed in single precision.

If

is

0, SON returns a 0.

of

the argument. The input

the expression

If

the expres-

is

given

is

in

10

INPUT A

20

PRINT SIN(A)

30

END

RUN

?8

.989358

Ok

SPACES

The SP ACE$ function returns a string expression.

NOTE

SPACE$ returns an actual string.

SPACE$

10 A

20 30 40 50 RUN QUESTION 1 THEORY

(integer

=1

PRINT "QUESTION";A;SPACE$(10);"THEORY" PRINT PRINT SPACE$(21);"TEXT" END

expression)

of

spaces equal to the value

of

the integer

TEXT

7-11

Functions

SPC

The

SPC

function returns a string PRINT not PRINT

statement, as in the example below.

return

an

actual string, only a series

statement.

SPC (integer) 10

PRINT

20

PRINT SPC

30

PRINT SPC (15);"How many states are there in binary

logic?":PRINT

40

INPUT A$:PRINT:PRINT

50

IF

A$ = "2"

saR

The

SQR function returns sion must evaluate returned.

SQR

is

calculated in single precision.

SQR(expression)

(10);

"Question

THEN PRINT

the

square

to

be greater

of

spaces n characters long when used with a

SPC, of

unlike the

spaces.

It

SP

ACE$ function, does

may

only be used with a

1 ":PRINT:PRINT

"Correct"

root

than

or

ELSE GOTO

of

the specified expression.

equal

to

zero,

or

750

an

error

The

message

BASIC·SO

expres-

is

The

program

then displays it:

10 20 30

below finds the square

INPUT A PRINT SQR(A) END

root

of

input A, which

RUN

?

45

6.70821 RUN

?

-1

ILLEGAL FUNCTION CALL

IN

20

STRINGS

The

STRING$ function returns a string number numeric code plied, the first character

of

times.

If

an

integer argument

is

returned the specified

of

the string

STRING$ (expression, expressionlstring expression) 10

A$

= STRING$(10,97)

20

PRINT

A$ RUN aaaaaaaaaa

OK

of

the same character repeated the specified

is

used, the ASCII character having

number

is

returned the specified number

of

times.

is

entered by the user,

If

a string argument

of

times.

is

that

sup-

7-12

10

A$=STRING$(10,"A")

20

PRINT

A$

RUN

AAAAAAAAAA

Ok

BASIC-SO

Functions

STR$

The STR$ function returns a string integer expression.

STR$ (expression) 10 FOR

20 30 40 RUN 0123456789 Ok

1=0

TO 9

A$

= A$ + MID$ (STR$ (I),

NEXT 1

PRINT A$

TAB

The TAB function spaces to most column tion

is before spacing PRINT the expression rounds

TAB 10 FOR

20 30

is 1 and

beyond the specified column, TAB will force a carriage return, line feed

to

the specified column. This function may only be used with the

statement.

If

the expression rounds

(expression)

1=

1TO 4 PRINT T NEXT

AS

(I); I

I

RUN

1

2

Ok

the

specified column position

the rightmost is the

to

over

WIDTH

3

4

of

decimal digits that represent the value

2)

at

the terminal.

WIDTH

to

value, TAB (expression

value.

a value less

If

the current

than

1,

MOD

TAB(1) results.

width) results.

The

print

of

the

left-

posi-

If

TAN

The

TAN

function returns the tangent value

is

radians. The calculation

T

AN

(expression)

10 20 30

INPUT PRINT END

A

TAN

performed in single precision.

(A)

RUN

?

41 .160656 Ok

USRn

The USRn function is used or

Fortran-80 subroutine. The DEFUSRn statement specifies the starting address

for the corresponding

to

24;

if

no

argument is given, 0

the result.

Hand

L.

If

none

is

to

reference a user-defined assembly-language, PL/M-80

USRn subroutine.

is

assumed.

indicated, the result must be returned as

of

the argument. The input

The

argument n may

The

type character indicates the type

is

given in

be

any integer from 0

an

integer in registers

of

7-13

Functions

BASIC-80

Only integers can be used as arguments; other variables must This

is

done with the V

ARPTR

function, which returns the address

be

passed by reference.

variable.

Here

USR[$I#l%

is

an

example of how the USRn statement

10

CLEAR 1000, ODFFFH

20

DEFUSR4 =

30

A$ = "A

40

A =

50

A# = 14D-3

60

AO/o

70

B = USR ! 4 (VARPTR(A!),VARPTR(K1),VARPTR(R#),VARPTR(LA%»

1E4

=

12

I!][n]

[(parameter

OEOOOH

STRING"

... )]

is

used:

Arguments are returned in a similar fashion, unless the type character

which case registers Appendix E gives details

Hand

L are used.

of

loading and running ASM-80,

PL/M-80,

FORTRAN-80 subroutines that may be called with USRn.

VAL

The VAL function returns the numerical value represent a valid number,

V AL(X$) equals

O.

of

string X$.

If

the string does not

of

the specified

is

omitted, in

and

VAL

(string

10

INPUT A$

20

IF VAL(A$) = 0 THEN

30

A1

40

PRINT A1,

50

END

60

PRINT

70

GOT010

RUN

expression)

= VAL(A$) *

A$

"ENTER

60

52

NUMERIC

DATA

ONLY."

?4

208

4

VARPTR

The V

ARPTR

put/

output buffer associated with a file number. assigned a value, an ILLEGAL V

ARPTR Arrays are passed BASE 1

is simple variables should be assigned values in a program before calling any array; otherwise, allocation all arrays to change. See Appendix E for further information about using V ARPTR.

VARPTR

function returns the address in memory of a variable

If

the variable has not yet been

or

the in-

FUNCTION CALL error results. The main use

is

to pass variable or array addresses to assembly-language subroutines.

by

in effect)

(variablel#file

specifying V

so

that

the lowest addressed element

ARPTR

of

a new simple variable

number)

(A

(0»

(or V ARPTR

of

the array

will

cause the addresses

(A(l»

is

returned. All

V

if

OPTION

ARPTR

of

for

of

7-14

APPENDIX A

Table

Error NEXT without

SYNTAX RETURN without Outof

Illegal function call

Overflow

Out

of

Undefined line number

Subscript

Duplicate Definition

Division by zero Illegal

Type mismatch

Out

of

String too long String formula too complex

Can't continue

Undefined user function No

RESUME

Unprintable error

FOR

ERROR

GOSUB_

DATA

memory

out

of

range

direct

string space

without error

BASIC-SO

A-I.

BASIC-80

Program contains no corresponding NEXT

Illegal usage No

GOSUB statement found to RETURN to.

All DATA statements read, tle data was included in the program.

Parameter passed to a function was out

Possible reasons:

1. A negative array subscript

2.

An

3.

LOG

4.

SQR

5.

AtB with A negative and B not

6.

A call to

DEFUSR

7.

Calls to MID$, LEFT$, WAIT, SPACES$, INSTR,

proper arguments

Variable with magnitude greater than

(single-precision

(double-precision floating-point)

Program too large, contains too many loops,

subroutines, variables, or complicated expres-

sions.

A referenced line does not exist.

You referenced

dimensions of the array, or referenced the wrong

number

You redimensioned

dimensioned.

A 'division by zero' operation was attempted.

An

instruction was used illegally in the Command

Mode.

A function which expects a string or variable was

given the wrong data type; any improper mix of

data types.

String variables are larger than the allocated

space. You can

String exceeds

String was too long or complex; break into two.

An

attempt was made to continue a program where an error occurred, or after modifications, or with no program.

Reference to a non-defined An error trapping routine has no RESUME. RESUME

routine. No error message exists for the given error.

Check

of

or

BASIC-80 tried to read too much,

array

subscript>

with a zero

with a negative argument

PEEK,

of

dimensions.

statement

ERROR

Error

Codes

Description

delimiters, characters, etc.

in

the program have been

32767

or

negative argument

USR

before a corresponding

POKE,

floating-point)

an

increas~

255

characters.

statements for undefined errors.

RIGHT$,

TAB,

or

ON

array variable outside the

array previously

space with CLEAR.

USR

without

ERROR CODES

FOR

for

or

too lit-

of

range.

an

integer

INP, OUT,

SPC,

...

STRING$,

GOTO

with im-

or

1.7D308

function.

error-trapping

3.4E38

Number

2

3

4

5

6

7

8

9

10

11 12

13

14

15 16

17

18

19

20

21

A-I

BASIC.80

Error

Codes

Table

A-I.

BASIC-SO

Error

Codes

BASIC-80

(Cont'd.)

Error

Missing operand line

buffer overflow

FOR

without NEXT

FIELD overflow

Internal

Bad File not found

Bad

File already open

Disk

File already exists Disk

Input

Bad Bad Direct statement

Too many files

error

file number

file mode

1/0

error

full

past end

record number

file name

Description Number

An operator was given without A program

for

the line buffer. Divide into two

A

FOR

corresponding NEXT More than

FIELD statement.

An error occurred in If this Intel representative.

An unopened A LOAD, KILL,

file not found on the specified disk. One

1.

2.

3.

4. An attempt to open

made. A

disk

means a sector read check failed File already exists. All disk space is full. Delete old files

disk.

An

INPUT statement has been given after the

end-of-file; check INPUT operations with the

function. The record number in a PUT or

An invalid ISIS-II filename was given.

in

file

A

direct

program into BASIC-80. The LOAD is terminated. An attempt to open a new

opened.

or

data line has too many characters

statement

128

characters were allocated in a

error

cannot be accounted for, contact your

file was referenced.

of

the following conditions apply:

The file mode is other than

PUT

or

GET

Opening a random file for sequential output,

or

vice versa.

Performing a PRINT to a random file.

1/0

error has occurred on disk (x); this

statement was found while loading a

BASIC-80 internal execution.

or

OPEN

to

a sequential file.

an

operand.

or

more parts.

was

found

statement referenced a

already opened file was

GET

file after 6 files were

I,

0,

18

without

or

R.

times.

or

is >

2048

try new

EOF

or

<

O.

22 23

a

24 50

51

52 53

54

55

57

58 61

62

63 64

66

67

A-2

APPENDIX B

BASIC-SO

The following list shows 126 words that cannot be used attempt to one or more alphanumeric characters, the first than

ABS AND ASC ATN ATTRIB AUTO

BASE CDBL CHR$ CINT CLEAR CLOSE CO

NT COS CSNG CVD CVI CVS DATA DEF DEFDBL DEFFN DEFINT DEFSNG DEFSTR DEFUSR DELETE DIM DIR DSKF EDIT ELSE END EOF EQV ERASE ERL ERR ERROR EXIT EXP FIELD FIX

do

so, errors,

two characters are given, the rest are ignored.

error

messages, or both will result. A valid variable name

of

FN FOR FRE GET GOSUB GOTO HEX$ IF IMP INP INPUT INPUT$ INSTR INT KILL LEFT LEN LET LINE LIST LOAD LOC LOF LOG LSET MERGE MID$ MKD$ MKI$ MKS$ MOD NEW NEXT NOT NULL OCT$ ON OPEN OPTION OR OUT PEEK POKE

which must be a letter.

RESERVED WORDS

as

names

of

variables.

POS PRINT PRUN PUT RANDOMIZE READ REM RENAME RENUM RESUME RESTORE RETURN RIGHT$ RND RSET RUN SAVE SON SIN SPACES$ SPC SQR STEP STOP STR$ STRINOS$ SWAP

TAB

TAN

THEN

TO

TROFF TRON USING USR VAL VARPTR WAIT WIDTH XOR

If

you

more

is

B-1

APPENDIX C

BASIC-80

BASIC-80 has certain single control characters (characters produced by pressing the letter and the immediately. These characters are listed below.

To

edit the last line entered:

To

halt program execution and return

level: To

tab across the line:

To

resume program execution after it

Control-S:

To

halt program execution until Control-Q

entered:

To

erase the current line:

To

retype the current line:

CONTROL key simultaneously) that cause something to happen

COMMAND

CONTROL-A

to

command

CONTROL-C CONTROL-I

is

stopped by

CONTROL-Q

is

CONTROL-S CONTROL-X CONTROL-R

CHARACTERS

To

disable display to the terminal (until CONTROL-O completion):

is

given again or the program runs to

CONTROL-O

C-l

APPENDIX D

Table

D-l.

ASCII Code List

Decimal Octal Hexadecimal Character Decimal

10 11 12 13 14

15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41

42

43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63

0 1 2 3 4 5 6 7 8 9

000 001 002 003 004 005 006 007 010 011 012 013 014 015 016 017 020 021 022 023 024 025 026 027 030 031 032 033 034 035 036 037 040 041 042 043 044 045 046 047 050 051 052 053 054 055 056 057 060 061 062 063 064 065 066 067 070 071 072 073 074 075 076 077

00 01 02 03 04 05 06 07 08

09 OA 08 OC 00

OE

OF

10

11

12

13

14

15

16

17

18

19 1A 18 1C 10 1E 1F

20

21

22

23

24

25

26

27

28

29

2A

28 2C 20 2E

2F

30

31

32

33

34

35

36

37

38 39 3A

3B 3C

3D 3E 3F

NUL

SOH

STX

ETX

EOT ENQ ACK

BEL

BS HT IF

VT

FF CR SO

SI

OLE

DC1 OC2 OC3

DC4 NAK SYN

ETB CAN

EM

SUB

ESC

FS

GS

RS US SP

!

"

*

$

%

&

,

(

)

*

+

,

-

I

0

1

2 3 4 5 6

7 8 9

,

<

=

>

?

64 65 66 67 68 69 70 71 72 73 74 75 76

n

78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96

97

98

99 100 101 102 103 104 105 106 107 108 109 110 111 112

113 114 115 116 117 118 119 120 121 122 123 124 125 126 127

Octal

100 101 102 103 104 105 106 107 110 111 112 113 114 115 116 117 120 121 122 123 124 125 126 127 130 131 132 133 134 135 136 137 140 141 142 143 144 145 146

147

150 151 152 153 154 155 156 157 160 161 162 163 164 165 166 167 170 171 172 173 174 175 176

177

ASCII

Hexadecimal

40 41 42 43 44 45 46 47 48

49 4A 48 K

4C

40 M 4E 4F

50 51 52 53 54 55 56 57 58 59

5A 58 [ 5C 50 5E 5F

60 61 62 63 64 65 66 67 68 69

6A 68 k 6C 60 6E 6F

70 71

72

73

74 75 76 77 78

79 7A 7B 7C 70

7E

7F

CODES

Character

@

A 8 C D E

F

G

H

I

J

L N

0

P

Q

R S T U V

W

X Y

Z

)

A

-

,

a

b

c

d

e

f

9

h

i j

I

m

n

0

P

q

r

s

t

u

v

w

x

Y

z

{

I

}

-

DEL

D-l

ASCII

Codes

BASIC-SO

Table D-2. ASCII

Abbreviation Meaning

NUL

SOH Start

STX Start ETX End

EaT ENQ Enquiry ACK Acknowledge

BEL Bell 7

BS HT Horizontal Tabulation

LF

VT

FF CR SO

SI

OLE DC1 DC2 DC3

DC4 NAK SYN Synchronous Idle

ETB End CAN Cancel

EM SUB ESC Escape

FS

GS

RS

US

SP

DEL

NULL Character

End

Backspace

Line Feed Vertical Tabulation Form Feed Carriage Return Shift Out Shift Data Link Escape Device Control 1 Device Control 2 Device Control 3 Device Control 4 Negative Acknowledge

End Substitute

File Separator

Group Separator

Record Separator Unit Separator

Space

Delete

Code

Definition

of Heading of

Text

of

Text

of

Transmission

In

of

Transmission Block

of

Medium

Decimal

Code

0

1

2 3 4 5 6

8

9 10 11 12 13

14

15 16

17

18 19 20 21 22 23 24 25 26 27 28 29

30

31 32

127

D-2

APPENDIXE

CALLING NON-BAStC-SO

SUBROUTINES

You can write a subroutine in FORTRAN-SO, PL/M':SO, language, convert it into relocatable code, load directly from BASIC-SO. Any number PL/M

You will need the ISIS-II User's Guide and the publication relevant to the language you use for the subroutine. The preface lists the Programming and manuals for FORTRAN-SO, PL/M-SO, and

conventions for passing parameters

of

it

into free memory, and access

variables can be referenced, following

to

subroutines.

SOSO/SOS5

or

SOSO/SOS5

assembly language.

assembly

it

Operator's

Preparing Subroutines

Once you have written the desired subroutine, follow the instructions in the appropriate compiler or Assembler your source language.

or

The compiler starting address starting address you can use, as well as the total free memory space.

4SK

A a highest usable address taken by the monitor

Intellec system has the highest usable address

assembler

in

Intellec system memory.

output

of

OF6BFH. Higher-addressed memory in both systems

and/or

Operator's Manual

is

a relocatable object code. This code

monitor RAM.

To

to

generate object code from

is

given a

do this, you must know the highest

of

OBEBFH. A

64K

system has

is

When you invoke The size

Suppose you have a 64K

usable memory address

it must start OEECOH, option when you invoke BASIC-SO. MEMTOP specifies the highest

BASIC-SO OEECOH,

If

looks like this:

If

the most economical use

and strings.

of

your main program

and you

leaving the space fromOEECOH-OF6COH for your subroutine.

-:F1

:BASIC MEMTOP ISIS-II BASIC-80 22620

you invoke BASIC-SO

-:F1: ISIS-II BASIC-80 24668

you locate your program as high as possible in free memory,

BASIC-SO, it immediately returns the free memory space in bytes.

and

subroutine(s) must

system,and a 2K

is

OF6BFH.

at

OEECOH. You must

~ust

forbid

may use. In the example below, MEMTOP specifies a boundary

BYTES FREE

on

a 64K Intellec System without specifying MEMTOP, it

BASIC

BYTES FREE

of

its remaining workspaces for string constants, variables,

If

you place your program next to the monitor,

besure

BASIC-SO

(OEECOH)

byte that there

to use this space with the MEMTOP

be

less than the free space.

(SOOH)

subroutine. The highest

is

2K

of

space available

BASIC-SO

RAlVI

can make

at

address

at

E-I

Calling Non-BASIC-80 Subroutines

When you have determined the optimum starting address for your subroutine, you can

LOCATE

it

there with this command. LOCATE converts the relocatable object code to absolute object code, according to the starting address given. An example giving the starting address for your subroutine code

is

shown below.

BASIC-80

of

LOCATE

This example converts the relocatable object code in object code in the subroutine relative

:F1

:PLMSUB.OBJ

output

to

OEECOH. Refer to the ISIS-II User's Guide for further details

file

TO

:F1

:PLMSUB.LD

:Fl

:PLMSUB.LD, and makes all addresses in the

CODE

:Fl

:PLMSUB.OBJ to absolute

(OEECOH)

of using LOCATE.

LOCATE has converted your relocatable code to absolute object code, you

After can load it into memory with the

DEBUG followed

enter

by

the filename

ISIS-II Monitor DEBUG command. When you

of

the load module, the subroutine

is

loaded into memory at the address specified in the load module. The starting address displays subroutine loaded

on

your terminal. You then enter GS, which returns you to ISIS-II with the

at

the specified address. From here.you can invoke

BASIC-SO

and

call the subroutine.

NOTE

You must give the MEMTOP option to reserve memory each time BASIC-SO

is

invoked.

Calling Subroutines

After a subroutine

invoke

BASIC-SO as you normally do, and give the MEMTOP option as previously

specified.

is

loaded into memory, you can call it from BASIC-80. First,

is

The first step in calling a subroutine tion. Up to 0-24. The starting address

25

subroutines can be addressed in this way, with an integer in the range

DEFUSR5=OEECOH

of

the subroutine

Once BASIC-SO knows where USR5

must supply any needed variables.

PL/M

addresses. the

pass the addresses

BASIC-SO where

conventions, you can only directly pass 2-byte integer variables or 2-byte

If

you specify a floating-point variable

V

ARPTR

120

function to pass the address

of

two floating-point numbers (Kl and

A = USR5 (VARPTR(K1), (VARPTR(K2»

goes to the address where

K2

is

stored (VARPTR(K2». Once it has found these two values, it passes

defining its address with the DEFUSR func-

is

given in hexadecimal:

is

located, you can call it. When you call it, you

Since the protocol for passing parameters follows

or

a string variable you must use

of

the desired variable.

For

example, to

K2):

Kl

is

stored (VARPTR(Kl) and the address

them to the subroutine.

If

BASIC-SO

locations

encounters new variables after executing line

of

Kl

and

K2

can change, causing errors.

120

above, the memory

Be

sure that all variables are

defined before using the VARPTR instruction. In the example shown, once the parameters are passed, the subroutine executes.

of

Because

PL/M-80

a two-byte integer in the

calling conventions BASIC-80 expects the returned result to be

HL

register-pair, and assigns this 16-bit value to A.

E-2

BASIC-80

Calling Non-BASIC-80 Subroutines

To return a single-precision floating-point, double-precision floating-point, or

string result, you must use the appropriate data type character (see table

2-5

for a list

function.

of

these characters) before the subroutine number in the USR

For

example, to tell

BASIC-SO

that a user-written subroutine

returns a double-precision floating- point value:

240

A# = USR

#15

(VARPTR(L#), A1)

In this example, the sharp sign (#) following USR tells S-

byte space for the double-precision result

of

USR #15. A#

BASIC-SO

is

to reserve an

also defined as

double- precision, but the parameters passed may be of any numeric type. Your subroutine must interpret the

of

address

A#, and it must also place the result

References to string parameters are handled in a similar manner. string

is

the address

of

the string descriptor, subroutine returns a string then the user should code 255-character string and pass the address

first

parameter passed to it as the storage

of

USR

#15

there.

V

ARPTR

not

the string data. Thus if a user

USR$[n]. BASIC allocates a

of

the string descriptor to the subroutine.

of

Your routine may change the string length in the string descriptor to return a shorter string,

but

may not change the string's address. Neither parameter strings nor

parameter string descriptors should be changed. Array variables are passed as parameters by referencing the first element

BASIC-SO follows row-major order.

array. To code in

8080/S0S5 assembly language, you must know the Intel format for

of

the

representing integer, single-precision floating-point, and double-precision floating

E-l

point numbers. Figure

~~D~ESS

ILS_f_I~~I

________________

shows these representations.

1_5_B_IT_S_O_F_DA_T_A

________________

LOW ADDRESS

~

a

INTEGER

REPRESENTATION: 2 BYTES,

8

EXPONENT

11

EXPONENT

8

LENGTH

STRING DESCRIPTOR REPRESENTATION: 8 16

BITS, STRING ADDRESS.

DATA DATA

BITS

SINGLE-PRECISION FLOATING·POINT 4

BYTES,

32

BITS,

LOW

BITS

DOUBLE-PRECISION FLOATING-POINT

BYTES,

84

BITS,

LOW

STRING

DATA REPRESENTATION: 8

ORDER

16

BYTE

Figure B-1. Internal Representation

BITS,

LOW

ORDER

BYTE

23

MANTISSA

REPRESENTATION:

FIRST

52

MANTISSA

REPRESENTATION:

FIRST

BITS,

DATA

of

BITS

ADDRESS

STRING

LENGTH:

DATA

BIT

BYTES.

Numbers and Strings

FIRST

E-3

Calling Non-BASIC-SO Subroutines

Some Real Examples

The three sample programs provided in Figures E-2, E-3, and E-4 show how the

subroutine-

same PL/M-SO,

and

three parameters.

adding three integer

SOSO/SOS5

arguments-can

assembly language. Notice

be coded in FORTRAN-SO,

that

each program requires

BASIC-80

Once you have processed your subroutine through the PL/M-SO compilers, object code and place it in memory with the filename subroutine code. In the example below ,

whose first byte

-LOCATE

or

through the

SOSO/SOS5

assembler, you can convert it to absolute

LOCATE command. You must give the

of

your relocatable code file and the proper starting address for the

LOCATE returns absolute object code

is

at

address

:F1

:PLMSUB.OBJ

OEOOOH:

CODE

(OEOOOH)

or

FORTRAN-SO

This command returns the absolute object file :Fl:PLMSUB. You can now load this located code into Intellec memory

at

its proper address with the monitor DEBUG

command. When you enter the DEBUG command with your filename, you invoke

the Monitor, as shown in the example below. The Monitor responds with a period

(.), expecting further commands:

-DEBUG:F1 #0000

:PLMSUB

You can now return to ISIS-II and test your subroutine. Leave the Monitor and return to

ISIS-II by entering

.G8 (CR) ISIS-II Vm.n

Invoke BASIC-SO, and specify the highest memory address

MEMTOP option:

the

GS

and a carriage return after the period:

BASIC-SO

can use with

-:F1

:BASIC MEMTOP(ODFFFH)

This prevents BASIC-SO from writing over your subroutine. and tell you how much free memory you have left:

ISIS-II BASIC-80 V1.0

18157

BYTES FREE

Once in BASIC-SO program defines your subroutine as

BASIC-SO

you can write programs that use your subroutine. The following

USRl,

asks for three integers, passes these three integer values to the subroutine, defines the result the variable

10 20 30 40 50 60 70 80

90 100 110

RESULT,

REM THIS PROGRAM ASKS REM INTEGERS, PASSES THEM TO USR1, AND REM RETURNS THE RESULT. DEFINT A-Z DEFUSR PRINT"ENTER THREE INPUT PRINT" RESULT=USR%1(VARPTR(A), VARPTR(B), VARPTR(C») PRINT"A+B+C="; END

and

1=OEOOOH

A,B,C

A="

,A,

finally prints RESULT:

FOR

THREE

NUMBERS:"

"B="

,B,

"C="

,C

RESULT

BASIC-SO

of

will appear

the subroutine as

E-4

BASIC-SO

Calling Non-BASIC-SO

Subroutines

ASN8B.OY3

ISIS-II

Lce

BBIS BBBI BSB4

BSB?

BIBA

IBBB

BBBC BBBF

BBl8

B813

BB14

BUS

B81'

BB17

BU8

BBlB

BIIC

BII0

BIlE

BI

B82B

8121

B822

B823

BBBB

:Fl:USRASH.ASH

8181/8185

09J

El 229BBB 21BBBB

COICBB

5B

59

COICBI

01

CDICBB

EB

El

73

23

72

2AIBBB

E9

E5

EB

5E

IF

23 5'

El

19

C9

88BB

BBBB

PUBLIC

SYMBOLS

USRASH C BBBB

"ACRO

D

C

o

C

SEQ

1

2

3

4

S

6

7

8

9

IB

11

12

13

14

15

16

17

18

19

2B

21

22

23

24

25

26

27

28

29

38

31 32

33

34

3S

36

37

38

39

ASSEHBLER.

ASSE"BLER

Y2.1

SOURCE

STATE"ENT

ROUTINE

RESULT=ARGA+ARCB+ARCC

IGNORE

OVERFLOW

NAHE PUBLIC CSEC

USRAS

..

:

POP SHLO H RETADR

LX

CALL "CY

"Cy

CALL PCP CALL

H.8

I

AODDE D.B E.C ADDDE

o

AODOE

XCHG

ADD

ROODE:

PCP "CY

INX

"CY LHLD

PCHL

2

BVTES

CHANCES

PUSH

H

PI.

H

H,D RE"TADR

;

RETURN

ADDRESSED

A.D,E.H,L

H ;SAVE XCHG "o.Y

IN

HOV PCP

DAD

E.H

X

H

0,"

H

o

RET

DATA

AREA OSEG

RETAOR:

OW

END

B

USRASH

E

USRAS"

TO

TEST

;RETURN ;5ET ; iAOD i"OVE

iAOD

; ADDRESS

iADD

;TOTAL

JADDR ;LOW

;HI ; RETURN

;AODR

;LOW

;HI ;OLO ;

;SAVED

SET

BY

ADD

BASIC

ASIDE

TCTAL ARCC

AOOR

ARCB

AReA

IN

o.F

BYTE

DE

TO

TOTAL

IN

BYTE

BVTE

TOTAL TO

RETURN

PACE

USR

AOOR

TO

8

TO.

TOTAL

o.F

ARCB

TO.

To.TAL

OF

ARG.A

TO.

To.TAL

DE

RESULT

OF

RESULT

OF

RESULT

ADDRESS

HL

L

TO

BE

TO.

BE

TOTAL

ADDRESS

TO

ADDED

DE

EXTERNAL

USER

SY"BCLS

S'/HBOLS

AODDE C BBIC ASSE"BLY

CO

..

RETAOR 0 BIBB

PLETE.

NO

ERRORS

USRAS" C BBBS

Figure E-2. 8080/8085 Assembly Language Program

E-5

Calling

Non-BASIC-SO

Subroutines

BASIC-SO

ISIS-II OBJECT COMPILER

2

3

4

5

6

CODE VARIABLE

~AXI"U"

11 LINES

a

PL/H-8B

",oDULE

INVOKED

1

2

1

AREA

STACK

PROGRAM

Vl.l

PLACED

COMPILATION IN

BY:

PLH8B

:Fl:USRPLM.OBJ

:Fl:USRPLH.PLH

PLM:$HODULE:

DO;

USRPLH: DECLARE DECLARE

ARCA ARCS ARCC

PROCEDURE(PRESULT,PARGA;PARGB,PARGC); (PRESULT,PARGA,PARGB,PARGC) (RESULT

BASED

BAseD RESULT=ARGA+ARG8+ARGC; END

END

SIZE

AREA

USRPL";

PLIUHOOULE;

BB32H SIZE SIZE

BlUSH

BBB4H

READ

ERROR(S)

Figure E-3.

PL/M-80

OF

MODULE

BASED PARCA. PARCB. PARCe)

SBD

SO

40

PLHHODULE

ADDRESS;

PRESULT~

ADDRESS;

Program

E-6

FORTRAN

1

2

3

4

CODE VARIABLE HAXI"UH

4

B

B END

COMPILER

AREA

STACK

LI

NES READ

PROGRAM TOTAL

OF

FORTRAN

PROGRAM

FUNCTION

IRTN(IARCA,IARGB,IARCC)

IRTH=IARGA+IARG8+IARGC RETURN END

SIZE

AREA

SIZE SIZE

ERROR(S)

BB20H OBB8H BBB4H

IN

PROGRAM

450

UNIT

ERROR(S)

COMPILATION

Figure E-4. FORTRAN-80

SO

40

IRTN

Program

APPENDIX F

RMX/SO

This appendix describes the differences between the and the ISIS-II version, generating disk-based or ROM-based versions mended that you refer to the

for supplementary information.

Guide

What

The Multi-Tasking Executive. With computational System, and apply them to solving a wide range

The BASIC-SO modules, coded to run as tasks under RMX/SO, are supplied on both single- and double-density diskettes. You can edit these modules with the Text Editor or CREDIT, and combine them with tasks. You use the Intellec Development

BASIC-SO

is

RMX/80

RMX/SO

iSBC

BASIC-SO Interpreter (iSBC

and

S02

software package gives you

tailor-made for your iSBC-based microcomputer system.

and

tells you the requirements and procedures for

RMX/SO

User's Guide and RMX/SO Installation

BASIC·80?

S02)

RMX/SO

input!

output capabilities of the iSBC/SO Microcomputer

BASIC-SO, you can easily use the powerful

RMX/SO

System to create a version

RMX/SO

of

RMX/SO

runs under the

of

application problems.

BASIC-SO

RMX/SO

version

BASIC-SO.

RMX/SO

in two forms. First,

and user application

BASIC-SO

of

BASIC-SO

It

is

recom-

Real-Time

ISIS-II

of

RMX/SO

This first

RMX/SO

describe how to configure your own frequent references to the following publications:

("configure your

software and be familiar with its use. The portions of this appendix that

own")

option requires you to have a copy

RMX/SO

BASIC-SO

system will therefore make

of

the

RMX/SO User's Guide, manual order no. 9S00522 RMX/SO Installation Guide, manual order no.

Second, if you want tional software routines, you can use the predefined

tion. This configuration includes three parts:

• The executable object module RMXSYS, supplied on both the single and double density diskettes.

• Two boot strap PROMs that load RMXSYS into the iSBC memory.

• A cable that connects the iSBC 204 disk controller to the bulkhead connector any Intellec disk drive chassis.

With this predefined version, you have a version

RESTART on your iSBC hardware configuration. You need only make the necessary hardware connections, and

You should be aware and ISIS-II based BASIC-SO. These are:

• Configuring the available to the figuration provides

• You must also specify the number configure the

at

files

once.

an

"instant-on" BASIC-SO system, and have no need for addi-

BASIC-SO

of

the major differences between

RMX/SO

BASIC-SO interpreter and the program source. The sample con-

S.4K bytes

RMX/SO

modules determines how much memory will be

of

memory space.

of

modules. The sample configuration supports 6 open

9S030S7-01

RMX/SO

of

is

ready to run.

files available to BASIC-SO when you

BASIC-SO

RMX/SO

configura-

on

that

appears on

based BASIC-SO

F-l

RMX/SO

BASIC-SO

• With RMX/SO BASIC-SO, you can create BASIC programs and program them PROMs for permanent reference.

into

• You can configure RMX/SO to execute a PROM-resident

immediately

•

If

you wish to interrupt program execution when

the console, you must enter

on

restart.

BASIC-SO

CONTROL-C followed by a carriage return.

wish to interrupt a program that has been stopped by a

BASIC-SO

expects input from

CONTROL-S, type

CONTROL-C followed by CONTROL-Q.

• RMX/SO BASIC-SO

does not have the EDIT Mode features supported by

ISIS-II BASIC-80.

• RMX/SO

BASIC-SO

supports only the console and disk files.

program

If

you

BASIC-SO

You should also be aware

of

two similarities between RMX/SO

BASIC-SO

ISIS-II BASIC-SO:

The

data

•

formats

(DFS) are identical. You can create

on

them

•

If

that

the other.

you use a random file

disk and insert another, you may destroy files on the new disk. You can

and

protocols

of

the ISIS-II

data

or

open a file for output

and

RMX·/SO

disk file systems

or program files on one system and use

on

one disk, and then remove

open files for input without problems.

Initializing

RMX/SO allows many different configurations PROMs that you can use to load BASIC-SO from disk and to execute it.

the

Predefined RMX/SO BASIC-SO Configuration

of

its modules. Intel supplies two

If

the required hardware, as listed below, you can quickly run the predefined BAS I

C-SO

configuration.

•

An

iSBC 80/30 Single Board Computer

• An additional32K bytes

•

An

iSBC

204

Disk Controller.

•

An

MDS-2DS Disk Drive attached through the cable supplied with the

of

RAM

on

two iSBC 016s, or one iSBC 032 board.

BASIC-SO package.

•

An

RS-232C compatible terminal.

• An iSBC chassis

and

power supply

and

you have

RMX/SO

F-2

If

you have the required hardware, it must be configured as shown below. Refer to

RMX/SO Installation Guide if you must alter your present configuration. Table

the F-l

shows the jumper configurations described in the following paragraphs.

1.

The iSBC SO/30

board

must be wired to conform to the RMX/SO terminal handler interrupt structure. This requires the wiring changes listed in Table Check your iSBC SO/30 board to verify that these changes have been made. For further information, refer to the

2. The iSBC on-board PROMs must be addressed at locations

RMX/SO User's Guide.

OOOO-OFFF.

This the factory-wired default configuration. These default jumper settings are shown in Table

Board Computer Hardware Reference Manual,

3.

The iSBC SO/30 on-board RAM must be addressed at locations 4000H-7FFFH. This

is

the factory-wired default configuration. These default jumper settings are shown in Table that disables off-board access to the

iSBC 80/30 Single Board Computer Hardware Reference Manual,

F-l.

For

further information, refer to the iSBC

chapter 2.

Jumper IS0-171

of

on-board RAM.

is

a factory-wired default configuration

For

further information, refer

SO/30

Single

chapter 2.

F-l.

is

BASIC-SO

Table

F-l.

Sample Configuration Jumper Wiring

RMX/SO

BASIC-SO

Board

iSBC 80/30 Handling

iSBC 80/30 PROM Addressing

OOOOH-OFFFH

iSBC 80/30 RAM Addressing 4000H-7FFFH

iSBC016 RAM Addressing 8000H-OFFFFH

iSBC

AddreSSing

204

Interrupt

Base

Connect

131-152 141-132 (EVENT 47-51

(ClK 143-127 (RXR INTR-IR 142-126 145-140 145-139

112-113 157-158 100-101 104-103 155-156 86-85

98-92 180-171 W1

at

Board 1 Board 2

Settings·

S2

7

ON

OFF

6

OFF

5 4 OFF

Jumper

(INTERRUPT

(TXR INTR-IR (Ground INTR 5.5) (Ground

position

ClK-IR1)

0-A12-11)

INTR 6.5)

A-B

-7-6

-7-5

Remove

2) 123-138 (COUNT OUT-INTR 7.5)

46-47

(ClK

7)

6)

47-52

(ClK

1-ClK O-ClK

Jumpers

0)

2)

*These the

4.

5.

numbers

switch

If

you are using two iSBC 016 Random Access Memory boards, you must jumper one to supply RAM memory from locations other to supply RAM from locations jumpers. at

locations 8000H-OBFFFH. On the other board jumper

nected, enabling memory

16K

RAM

The iSBC

interrupt level 2. The base address S2 are shown in Table

refer

to

the

silk-screened

bank.

numbers

on

the

PC

board,

not

to

the

numbers

8000H -OBFFFH and the

OCOOOH

to OFFFFH. Table

F-llists

On one board, jumper 7-6 must be connected, which enables memory

7-5

must be con-

at

addresses

OCOOOH-OFFFFH.

Refer to the

iSBC

Board Hardware Reference Manual for further information.

204

Disk Controller must be set to base address 80H and set

is

F-l.

Interrupt level 2

set by switch

S2.

The four switch settings

is

the factory-wired default configuration. To verify interrupt level 2 operation, check for a wire jumper connecting terminal posts information, refer to the

Reference Manual,

6.

The iSBC 204 Disk Controller must be the highest priority bus master. You can place the

iSBC 204 in the top chassis slot with the iSBC

or you can rewire the chassis backplane appropriately (see the

ware

Reference Manual for details). The supplied cable attaches from

204 controller to the plug

iSBC

63

and 67. Table F-l lists these connections. For further

iSBC

204 Flexible Diskette Controller Hardware

chapter 2.

80/30

directly under it,

iSBC

on

the rear

of

the MDS-2DS disk drive.

80/30 Hard-

11

these

016

of

the

on

at

of

F-3

RMX/SO BASIC-SO

BASIC-SO

When you have configured your system, follow these steps

1.

Insert the supplied

80/30.

2.

Turn

on

power to the disk drives and iSBC system.

3. Insert your single density

4. Type

an

upper case U

RMX/80 BASIC-80 Vm.n

PROMl

at

in socket 0 and PROM2 in socket 1

BASIC-80 disk into drive

the terminal keyboard until the sign-on notice prints:

to

initiate BASIC-80:

O.

of

the iSBC

Generating Boot-Loaded and PROM-Based Versions of

RMX/SO

Intel supplies two diskettes with the following modules. One diskette sity; the other double density. You can modify and configure these modules to suit many possible combinations

BASIC-SO

of

hardware and software.

is

single den-

BASIC-80 Source Files

BOOPS.ASM This module contains options used by other assembler modules.

of

Figure F-I shows a sample listing

BOOTCM.ASM This module configures the BASIC Boot Loader. BOBMEM.ASM This module allocates memory for the BASIC Boot Loader. BASCM.ASM This module configures BASIC. BOMEM.ASM This module allocates memory for BASIC.

this module.

BASIC-80 Object Files

BASIC.LlB This library contains all modules used by BASIC except for the

following, which are generated by assembling the corresponding .ASM modules:

BOOTCM.OBJ BOBMEM.OBJ BASCM.OBJ BOMEM.OBJ

CLOCK.OBJ

This module

is

a dummy clock module used with the iSBC 80/10.

BASIC-80 Executable Files

BOBOOT This module

PROM.

RMXSYS

This module by the Boot Loader.

Software Requirements

You must have the following software tools and modules available in the appropriate drives to generate versions

Drive

0:

In drive 0, you must have a disk with these modules:

ISIS-II All Link, Locate, and the

is

the Boot Loaded system, which

is

the version

for

Generating

of

V3.4 (or later version)

of

the modules described above.

of

RMX/SO BASIC-80 which

RMX/80

BASIC-80.

ASMSO

is

also provided

BASIC-80

Macro Assembler

is

loaded

on

F-4

BASIC-80

RMX/80

Drive 1: In drive I, you must have a disk with these modules:

RMX/SO nucleus, factory-configured for an iSBC

The

SO/IO,

SO/20,orSO/30.

The RMX/SO extension files, including the Disk File System, and the RMX/SO Boot Loader files for the appropriate

CPU

board.

Once these two disks are present in the proper drives, you can begin configuring your

RMX/SO BASIC-SO version. We'll look

kinds

of

BASIC-SOs-a

boot-loaded version and a PROM-based version.

at

procedures and examples

of

two

BASIC-80

Generating a Boot-Loaded

The software requirements

RMX/80

for

generating a boot loader and a compatible version

BASIC-80

of

BASIC-SO are listed above. You must have the two disks in their proper drives with

on

the given modules

The hardware requirements for the

each disk.

boot

loader and its accompanying version

of

BASIC-SO are:

An

iSBC 201, iSBC 202, iSBC 204, or iSBC

206

Disk Controller, with its

necessary cables, and the disk drives it controls. An

iSBC SO/IO, iSBC SO/IOA, iSBC SO/20, iSBC

At

least

4SK

bytes

of

RAM if DFS

If

you use

total. An

RS-232C compatible terminal, and accompanying cables.

an

iSBC SO/30, the

You can use any combination

There are three steps to generating a

1.

You must examine and,

2.

You must also examine the BOOTCM

if

necessary, modify the BQOPS.ASM module.

is

used, or

16K

bytes

of

iSBC RAM boards.

boot

loader

and

32K

SO/20-4,

bytes

or

of

RAM if

iSBC SO/30.

it

is

not

used.

RAM on-board count toward the

for

RMX/SO BASIC-SO:

BQBMEM modules and modify

them as needed.

3.

After you have verified that the various assembly modules accurately reflect your hardware and software configurations, you

SUBMIT the GBOOT.CSD

module, shown in figure F-2, which assembles BOOTCM.ASM and

and

BQBMEM.ASM

LINKs

and

LOCATEs the boot loader.

Modifying

the

BQOPS.ASM

Module.

The BQOPS.ASM module contains

data

used by the BOOTCM.ASM, BQBMEM.ASM, BASCM.ASM, and BQMEM. ASM modules. In most cases, this will be the only module you will modify before assembling modules for a new configuration. The boot loader configuration requirements are dependent upon the

number change from configuration

of

disk drives available, and the highest memory location; if these do not

to

CPU

model, the disk controller model, the

configuration, then the

boot

loader need not be

regenerated.

With the

ISIS-II Text Editor

listed in figure F-I

Guide for

an

explanation

to

support your exact configuration. Refer

of

or

CREDIT, you can edit the BQOPS.ASM module

to

the ISIS-II User's

the

Editor's

features and capabilities.

F-5

·

RMX/SO

BASIC-SO

CPU

BOOTED

TERMH SET

RATE CONTR DFS UIO SET NFILES SET HIRAM BOTMEM

SET SET

SET SET SET

SET OFFFFH

SET

;

MODEL

30

1 ; 1 IF BOOT VERSION, ELSE 0 1 ; 1 FOR

;

BAUD

0

; CONTROLLER NUMBER

204

;

NUMBER

6

; 1 IF USER

0

;

TOTAL

6

; HIGHEST RAM LOCATION

OFD40H

;

BOnOM

OF CPU

FULL

TH,O

RATE FACTOR

OF DFS FILES USED

110

FILES

OF BOOT

FOR MINI

DRIVERS ELSE 0

L9ADER

RAM

BASIC-SO

Figure

F-l.

Sample

Configuration

Each of the options in the sample configuration is

explained

CPU

in

the following paragraphs.

This option specifies the type or 80/10A, 20 for iSBC 80/20 or 80/20-4, or 80/30.

It

is

only referenced by the BQMEM.ASM module to

initiate interrupt polling for

boot

loaded.

to

allocate memory.

BOOTED

TERMH

that are not This option is used

is

loader

used, or 0 if a PROM-based BASIC-80

With this option, a 1 specifies the Full Terminal Handler, and a 0 specifies the Mini Terminal Handler. The Mini Terminal Handler requires less RAM and

RATE

This option generates an RQRATE to specify a baud rate if

is

any non-zero value

given. For further information about

setting baud rates, refer to the

CONTR

This option specifies the type indicates an iSBC 201;

DFS

dicates an

iSBC 204;

This option specifies the number of DFS files you wish to

at

have open

the same time. Specifying 0 means that DFS

206

not used.

BQOPS.ASM Module

BQOPS.ASM module listed above

of

CPU used:

10

for iSBC 80/10

30

for

iSBC

iSBC 80/10 based DFS systems

It

is

1 if the boot

is

generated.

PROM space.

RMX/SO User's Guide.

of

disk controller used.

202

indicates an iSBC 202;

indicates an

iSBC

206.

204

201

in-

is

F-6

UIO

NFILES

HIRAM

BOTMEM

This option enables your user-written specify

1. See "Adding User-Written

I/O

drivers if you

I/O

Drivers" in this

Appendix for further details. This option specifies the combined number

that

files than

may be open

or

equal to the number specified in the DFS option.

at

once. The number must be greater

of

DFS and user

This option specifies the highest RAM location available in the hardware configuration.

This option places location. This address should be 2BFH

boot

loader RAM

at

the highest possible

less

than the address

given in HIRAM.

BASIC-SO

RMX/SO BASIC-SO

After you modify BQOPS.ASM and verify the contents

of

the BOOTCM.ASM and BQBMEM.ASM modules, you are ready to generate your boot loader. To do this, you must assemble the resultant object code. The GBOOT.CSD module command. Figure F-2 BQOPS.ASM module in figure

The DATA location and the BOTMEM address must configuration uses an changed to burned into

BOOTCM.ASM and BQBMEM.ASM, and LINK and LOCATE

will

do this with the SUBMIT

is

a listing

of

the GBOOT .CSD module used with the

F-l.

be

S20

or

iSBC

SO/20

or iSBC S0/10, each occurrence

SID.

After you have generated the boot

the same.

If

of

loader,

your hardware

S30

it should be

PROM and inserted into your CPU board. (See the Universal

should be

PROM

Programming Manual for details)

iSBC

SO/10

The

does not have an onboard clock. clock, add the appropriate routines when linking G of the

RMX/80

User's Guide for further information.)

in your configuration, include the dummy clockroutine

ASM80 ASM80 LINK

LOCATE

:FO:BOOTCM.ASM MACROFILE(:FO:) NOSYMBOLS :FO:BQBMEM.ASM MACROFILE(:FO:) NOSYMBOLS :F1

: BOT830.LlB(VECRST)

:F1

:RMX830.LlB(START)

:FO:BOOTCM.OBJ, :FO:BQBMEM.OBJ, & :F1 : BOT830. :F1

:DI0830.LlB, &

:F1

:DFSUNR.LlB, &

:F1

:RMX830.LlB, &

:F1

:BOTUNR.LlB, &

:FO:PLM80.LlB

:F1

:BQ800T.LNK

CODE(40H)

LIB, &

&

TO

:F1:BQBOOT.LNK MAP PRINT(:F1:LNK.LST)

TO

DATA(OFD40H)

:FO:BQBOOT MAP PUBLICS PRINT(:F1 :LOC.LST)&

ST

ACKSIZE(O)

If

your configuration includes a

GBOOT.CSD. (Refer to Appendix

If

you

don't

have a clock

CLOCK.OBJ.

Figure F-2. Sample

Configuration

OBOOT

.CSD

Module

Generating a Boot-Loadable BASIC-80. Once you have determined how to generate the boot loader that fits your particular of your work

over. Generating

BASIC-SO

is

There are four steps to generating a boot loadable

BASCM.ASM and BQMEM.ASM modules, and linking and locating the

the

resulting

BASIC-SO

into RMXSYS. The GBASIC.CSD module

that performs these steps. Figure F-3 shows a listing of the

If

used with the sample configuration.

based system, you need

"S20"

with the ISIS-II Text Editor.

Editor, refer to the

to

modify the

ISIS-II User's Guide.

you are using an iSBC

"S30"

For

The CODE and START addresses should reflect the addresses

RMX/SO implementation, the bulk

is

relatively simple.

RMX/80

BASIC-80: assembling

is

a SUBMIT file

GBASIC.CSD module

80/10

or

iSBC

SO/20

references in the module to

"SI0"

or

further information about using the Text

at

the start of system

RAM. The following list shows typical starting addresses:

iSBC80/10or80/10-A iSBC 80/20 iSBC 80/20-4 iSBC 80/30

3COOH

3800H 3000H 4000H

F-7

RMX/80

BASIC-80

The ed for the system clock) as EXTERNAL. This tasks must define the exchanges as needed. Any not used in a system, and therefore not declared in user code, an unresolved external reference by the linker, the locater, ICE-80, and ICE-85. Messages issued by these products changes can be considered as warnings and ignored. The messages issued by the various products are:

RMX/80

NOTE

Nucleus declares all interrupt exchanges except

is

because user interrupt

of

these interrupt exchanges

that

refer to unused interrupt ex-

RQLIEX

is

treated as

BASIC-80

(us-

Linker:

Locater:

ICE-80 ERR=069 ICE-85 *WARNING UNSATISFIED EXTERNALS

UNRESOLVED EXTERNAL NAMES

xxxxx xxxxx

etc.

UNRESOLVED EXTERNAL REFERENCE AT xxxxH

(two messages

for

each exchange)

You should check the messages to be certain that none of them refers to anything other

RMX/80

Reference Manual shows one way to

an unused interrupt exchange. Appendix J

"tie

off"

references to unus-

of

the

than

ed interrupt exchanges in a configuration module.

ASM80 :FO:BASCM.ASM MACROFILE(:FO:) NOSYMBOLS ASM80 :FO:BOMEM.ASM MACROFILE(:FO:) NOSYMBOLS LINK &

:F1

:LOD830.LlB(LODINI),& :FO:BASCM.OBJ,& :FO:RMXBAS.LlB,& PUBLlCS(:FO:BOBOOT),& :F1

:LOD830.LlB,& :F1

:DFSDIR.LlB(SEEK,DIRECTORY ,ATTRIB,DELETE,RENAM E),& :F1

:DI0830.LlB,& :F1

:DFSUNR.LlB,& :F1

:THI830.LlB,& :F1

:TH0830.LlB,& :F1

:RMX830.LlB,& :F1

:UNRSLV.LlB,& :F1

:PLM80.LlB,& :FO:BOMEM.OBJ TO :F1:BOBAS.LNK MAP PRINT (:F1:LNK.LST)

LOCATE :F1:BOBAS.LNK TO :FO:RMXSYS MAP PUBLICS PRINT(:F1:LOC.LST)&

CODE(4000H) STACKSIZE(O) START(4000H) PURGE

F-8

Figure

Generating a PROM-Based

You can also configure bytes

of

PROM, 2.8K bytes of RAM, and 400 bytes

F-3.

Sample

RMX/80

Configuration

RMX/80

GBASIC.CSD

BASIC-80

Module

BASIC-80 to reside in PROM. This requires

of

RAM for each DFS file

33K

BASIC-80 will use. You should also set aside as much RAM as possible as workspace for

BASIC-80.

Intel 9800758-02 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual