Atari 400 Basic Reference Manual

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CONTENTS

PREFACE GENERAL INFORMATION

1

Terminolog

Sp

ec

ial

Abbreviations Used

Operating

Spe c

ial Arithmetic Operator Built-In Graphics Sound

ra

p a

W Error

COMMANDS

2

BYE CONT

ND

E LET LIST NEW REM RUN S

TOP

y

Notations Used In

In

Modes

Function Keys

Operator

Precedence

Functions

and

Games

round

Messages

and

s

Key

This Manual

board

Rollover

vii

1 3 4

5 5

6 7 7 8 8 8 8

9 9 9

10 10 10 10 11 11

EDIT FEATURES

3

ee

n E

Scr

Control Shift

Dou b le K

Cursor Keys Keys

Special

Break Key Escape Key

4

PROGRAM STATEMENTS

FOR/NE GOSUBIRETURN GOTO I

F/THEN

diting

(CTRL) Key

Key

ey Functi

Control Used With Used W Function

XT/STE

ith

P

on s

Key s

CTRL Key

Shi

ft Key

Key s

Contents

13 13 13 14 14 14 14 14 14 14

15 16 17 18

iii

ON/GOSUB

ON!GOTO

POP RESTORE

TRAP

5 INPUT/OUTPUT COMMANDS

20 20 20 21

22

Input/Output CLOAD CSAVE

DOS ENTER INPUT LOAD

LPRINT NOTE OPEN/CLOSE

POINT PRINT

PUT/GET

READ/DATA SAVE STATUS

XIO Chaining

FUNCTION LIBRARY

6

Arithmetic

ABS CLOG EXP INT LOG RND SGN SQR

Trigonometric

ATN

Devices

Programs

Functions

cos

SIN DEG/RAD

Special

ADR FRE PEEK POKE USR

Purpose

Functions

23

24 24

25

26 26 26 26 28 28 28 28 29 29

30

33

33 33 33 33 34 34 34 34 34 34 34 35 35 35 35 35

35 35 36

7 STRINGS

ASC CHR$

Contents

iv

37 37

LEN STR$ VAL Str

ing Manipulation

38 38 38

s

39

ARRAYS

8

DIM CLR

GRAPHICS

9

GRAPHICS Graphics

ModeO Modes 1 Mod Modes4 and6

Mode8 COLOR DRAWTO LOCATE PLOT POSITION PUT /GET SETCOLOR XIO (Spe Assigning Graphic

SOUND

10

Modes

and

es

3, 5, an d 7

cial

Fill

Colors

s Contr

AND

MODES

2

Application)

to

Text Modes

ol Char

GAME

MATRICES

AND

acter

COMMANDS

s

CONTROLLERS

41 43

45 45 46 46 47 48 47 48 48 48 49 49 49

50

54 54 56

SOUN D PADDLE PTRIG

ST

ICK

STRIG

11

ADVANCED

Mem or y Con Programming

APPENDIX

APPENDIX APPENDIX

APPENDIX

PROGRAMMING

servat

ion

In Mac

A

BASIC

B

ERROR

C

ATASCII WITH

hin

e La

RESERVED

MESSAGES

DECIMAL

HEXADECIMAL

D

ATARI MEMORY

TECHNIQUES

ngu

age

WORDS

CHARACTER

/ LOCATIONS

400/800

MAP

SET

Conte

A-1

B-1

C-1

D-1

nts

57 59 59 59 60

61 63

V

APPENDIX

E

DERIVED FUNCTIONS

F

PRINTED

VERSIONS

CONTROL CHARACTERS

E-1

OF

F-1

APPENDIX APPENDIX APPENDIX INDEX

G GLOSSARY H USER PROGRAMS I MEMORY LOCATIONS

G-1

H-1

1-1

117

vi

Contents

This

manual

Guide

or

BASIC.

special

The photostats bols

clear

chosen

techniques.

Each

dealing

all

dices

memory

As

this

contains

It

applications

programs

in

the

screen

to

of

the

with a particular

the

statements

include

locations,

there

is

manual

programs

assumes

some

other

is a

reference

and

oflistings

Atari

symbol

illustrate a particular

sections

quick

no

one

is

directed

the

book

guide

of

Atari® BASIC.

partial printed

character

'~"

contains

aspect

pertaining

references

and

the

specified

at

general

that

illustrate a few

user on

programming

set

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application

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BASIC.

to

on

the

do

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function-

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to

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to

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820™

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BASIC.

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For

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Atari

and

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PREFACE

BASIC - A Self-Teaching

is

not

intended

statements,

used

in

Some

of

same

on

the

examples

"good"

functions,

instance,

messages, BASIC

Personal

the

general

system's

Section 9

capabilities.

Computer

user.

capabilities.

to

functions,

this

manual

the

special

printer;

in

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text

programming

or

statements

The

keywords,

Appendix

"teach"

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e.g.,

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were

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appen-

System,

H

Preface

vii

This

section

used

in Personal BASIC

commands

explains

this

manual,

Computer

BASIC

and

Systems

deal

with

terminology,

the

special

keyboard

specific

GENERAL

INFORMATION

special

keys

on

.

It

also

applications.

notations, and

the

AT

points

ARI 400™

to

other

abbreviation

and

AT

sections

ARI

1

800

where

s

™

TERMINOLOGY

BASIC:

BASIC

used for

BASIC RUN.

Constant:

by a variable

100

Command

same

Expression:

operators, either

Function:

called expression. "returned"

RND

functions. In var mediately. might

Beginner's

Keyword:

in a statement, as a command,

a list

of

all

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A

is a constant.

String:

numbered

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A

for

by

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to

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iable)

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See Section 6

appear

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compute a value.

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BASIC

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AT

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rather

X =

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of variables

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SPECIAL NOTATIONS USED

IN

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ENTER

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LIST filespec cassette. entered,

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Note:

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PRINT

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100

statements

(:).

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INPUT LIST END

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PRINT

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2000

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,

ABBREVIATIONS USED IN THIS MANUAL

Command

breviation of

the

command

The

following

avar

svar

mvar

var

abbreviations

associated

in

table

with

the

explains

TABLE

Arithmetic

stored. characters, alpha

characters

String

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Matrix

ment matrix

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element) variable, array

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The

subscripted.

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as a whole

ZIP,

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in

headings:

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the

heading;

the

1.1

Variable:

Variable

but

must

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in

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See Section 7,

Variable:

an

array

or

K.

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starts

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matrix

Any

If a command

abbreviation

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e.g., LET (L.).

abbreviations

ABBREVIATIONS

A

location

names

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A

name

variable

or

variable.

may

start

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be

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rules

name

Also

called

matrix.

may

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matrix variable,

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be

where a string

as

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STRINGS.

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The

legal variable

variable

example,

be

or

statement

placed

following

used

throughout this

where a numeric

from 1 to

an

alphabetic

and

upper

of

avar

apply,

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variable

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name

(name

and

then

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mvar,

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the

120

alphanumeric

character,

case.

characters

except

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variables

for

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such

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use

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A(1),

or

svar

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value

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A,

particular

s a

number,

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.

ab-

is

all

be

last

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or

X,

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4 General Information

aop

lop

aexp

lexp

Arithmetic

Logical

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function,

operator.

constant,

arithmetic

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string

pression

For while (false) as

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expressions

evaluates

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the

operator.

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or

operator

to

the

expression

two

strings

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composed

expressions

.

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separated

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a 1 (logical

1<

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"LEMON" = "ORANGE"

are

not

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arithmetic

operator.

or

to

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the

value 1 (true)

evaluates

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or

an

ex-

to a zero

,

sexp

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a

data

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(constant),

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line

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program

ATASCII

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returns.

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of a string

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numbering

character

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Section 5.)

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General Information 5

"

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to

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.

ARITHMETIC OPERATORS

LOGICAL OPERATORS

6 General Information

Emil

The

Atari

+

addition subtraction multiplication

*

I

division

A

exponentiation

The

logical

operator

Clear

mill

corner.

Return

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mode)

are

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(also

operators

is

NOT.

key:

key

placed

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unary

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Pressing

blanks

key:

this

to

a BASIC

is

interpreted

in a variable

plus;

unary

minus;

consists

binary

this

the

screen

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key

causes a

program

and

System

e.g.,

+ 5)

e.g., - 5)

of

two

operators

key

and

to

numbered RAM.

executed

table.

uses

types:

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indicate

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five

arithmetic

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holding

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and

unnumbered

immediately.

line

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cursor

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operators:

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upper

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variables

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or

left

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10

IF

10

A=(C>l)

10

A =

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A =

The

rest

<

The

>

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-

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< =

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> =

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A=12

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expression first

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expressions

T=0

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OR

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operators

are

THEN

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greater equal is less is

greater

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F'RWT

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to

than

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relational.

the

than

each

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or

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equal

to

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second

the

equal

or

equal

each

11

expression.

second.

to

the

to

other.

Both expressions

must be true before GOOD is printed.

If

both

expressions

true,

A= + 1;

otherwise

A=O.

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either expression

1;

true, A= +

otherwise

A=O.

If

expression is false,

A= + 1;

second.

the

otherwise

second.

A=

0.

OPERATOR

PRECEDENCE

These

operators

arithmetic.

Operations ceed

out

to

they

are

said

in

the

following

Highest precedence

Lowest precedence

within the

to

<,

>,=,<=,

* ' I

+,

-

are

the next be

"nested".

order:

NOT

AND

OR

most

innermost

level.

When

>=,<->

frequently

set

sets

Operations

Relational sions.

formed

Unary Exponentiation. Multiplication precedence to

Addition

precedence to Relational have right. Unary Logical Logical OR

used

of

parentheses

of

parentheses on

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Have

from

minus

right.

the

operator

AND

in

IF/THEN

are

same

operators

same

left

and

level

and

subtraction

level

and

operations

same

precedence

statements

performed

are

enclosed

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used

precedence

to

right.

division

are

performed

are

performed

in

numeric

level

in

have

level

and

first

in

another

are

performed

string

and

have

the

expressions

from

and

expres-

are

the

from

logical

pro-

set,

per-

same

left

same

left

to

General

Information

7

BUILT-IN FUNCTIONS

GRAPHICS

SOUND

AND GAMES CONTROLLERS

WRAPAROUND AND

KEYBOARD

ROLLOVER

The

section

functions

Atari

graphics

to

allow

plains

each

The

Atari including defines dle,

joystick,

The

ATARI

greater presses

titled

incorporated

include 9 graphics

maximum

command

Personal

simulated

the

commands

and

Personal

flexibility.

and

holds

FUNCTION

into

flexibility

and

gives

Computer

explosions,

for

keyboard

Computer

It

also

allows

any

key,

LIBRARY

Atari

BASIC.

modes.

in

color

examples

is

capable

electronic

using

the

controllers.

System

the

it

will

begin

The

choice

of

music,

SOUND

has

user

to

repeating

explains

the

emitting a large

function

screen

the

commands

and

pattern

many

and

wraparound

type

one

after

arithmetic

ways

"raspberries."

and

key

1

h

have

variety.

to

variety

for

controlling

ahead.

second.

and

special

been

designed

Section 9 ex-

use

each.

of

sounds

Section

thus

allowing

If

the

.

10

pad-

user

ERROR MESSAGES

If a data ed correcting

ERROR- before

messages

by

entry

the

and

message

the

error

is ERROR-

character

pressing

their

definitions.

made,

in

IDi!liJI.

the

screen

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display

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offending

original

Appendix B contains

line,

shows

the

character

delete

the

line

is

line

a list

reprinted

highlighted.

containing

of

all

the

preced-

After

the

error

8 General Information

2

COMMANDS

BYE (B.)

CONT(CON.)

Whenever cept

input.

IDiJ3.

and

other

The

commands

Format:

Example:

The

current

puter

in

or

to

leave

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Format:

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W1!llilli

following

the

Type

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useful

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messages

To

this

If

a

the

cursor

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section

control

explained

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function

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return

CONT CONT

command

l:l;liiM,

is

entered.

statement

(D)

is

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command

describes

commands:

in

BYE

CONT

END

LET

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of

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This

on

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to

BASIC,

followed

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or

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at

which

(in

the

this

section

BYE

allows

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press

END is

on

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either

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user

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by

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program

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execution

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to

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memory

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keyboard

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stop

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END

Note:

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Format:

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before

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program

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statement

numbered

END,

the

END 1000 END

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any).

at

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BASIC

also

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the

program

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execution

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automatically

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mode

and

end

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halted

of a program.

mode

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at

the

time

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used

in

closes all files

to

close files

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mode.

the

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9

LET (LE.)

Format: Example:

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statement

the

statement.

[LET]

var = exp

LET X = 3.142 * 16 LET

X=

2

is

optional

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may

be

in

used,

defining

however,

variables.

to

set a

It

can

just

variable

as

easily

name

be

equal

left

out

of

to a value.

LIST (L.)

Format:

Examples:

LIST LIST [filespec [

LIST LIST LIST I 101

LIST LIST 110:

This

command rently display a specified 10 puter

Typing

LIST TRAP

The ond peripheral need

in

through

in

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can

in

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causes

memory

100

on

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will

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command

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devices.)

specified.

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the

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4).

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entire

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used

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]

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to

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example,

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user

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automatically

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part

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place

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to

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on

Section 5 for

listed

on

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number(s),

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them

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displays into

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more

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order.

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details

numbers

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or

lines

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(See

sec-

on

to

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REM (R.

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10

Commands

or

Example:

Format: Example:

This

command

NEW,

either

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clears

strings

Format: Example:

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(See

command

statement

by

the

lines.

LIST

"C1"

1000 LIST

NEW NEW

erases

SAVE

BASIC's

Section

REM

text

10

REM

and

computer.

Any

will

"C1"

the

or

CSAVE

internal

7)

are

defined.

ROUTINE

the

text

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statement

be

ignored.

program

any

symbol

TO

following

on

stored

programs

Used

CALCULATE X

it

the

table

in

it

are

is

included

same

in

RAM. to

so

that

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for

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numbered

Therefore,

be

recovered

no

mode.

user's

in

a LIST

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line

(See Section

information

along

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before

and

with

occurs

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only.

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typing

later.

8)

or

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after

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RUN

(RU.)

Format: Examples:

This

command is specified, included, specified file

All

rays,

the

detected

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the

variables

strings,

TRAP

during

can

be

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"D:MENU"

causes

the

current

computer

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command

execution

used

in

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the

computer

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zero

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are

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and

the

mode.

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the

specified,

open

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program

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begins

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halts.

execution.

tokenized

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is

displayed

program

are

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if

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from

closed.

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off. Unless

any

error

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ar-

is

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Type

RUN

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begin

GOTO

Format: Example:

When message returns sounds,

followed

the

to Direct so

19

PRINT 110VER

20

R~

and

press

program

by

STOP 100 STOP

STOP

command

STOPPED

mode.

the

program

l;ljili;lli.

execution

the

specific

AT

LINE

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can

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end,

at a point

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is

executed

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be

resumed

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pressl:!dy.i:i.

other

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,

terminates

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than

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CONT l;l§iii;lll.

line

BASIC

number,

displays

execution,

or

turn

type

the

and

off

Commands

11

NOTES

12

Not

es

In

addition control conjunction

The

following

keys

to

that

with

the

key

special allow the

4.jiii$M or

functions

function

immediate

Gml Gml

4

111

41

1

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D

Gml

41111jM

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=

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keys

described

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are

described

11

H-i3;il

editing

capabilities.

keys.

in

mDI

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mma

MIP.!itiJ«•M;M

EDIT

FEATURES

in

this

Section 1,

These

section:

m1l Gml m1l

there

keys

1

2

3

'='d:t.U'

..

are

3

cursor

used

in

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keyboard

known

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in

Example:

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The

41111$4

as

key

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delete

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screen

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2t1

30

line

deleting

and

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be

f1

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20

from

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display

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pressed.

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the

program,

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as

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program Striking a key duce three

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numeric

upper

are

logically

time a change

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f·.iT

IS

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type

from

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screen

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arrow

keys

allow

the

screen

the

without screen. and

lists,

the

upper-left

functions.

key:

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keys

half

oft

combined

the

change

AFTEF

1

the

line

display

are

described

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produces

user

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clearing

and

while

key

to

display

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completed

is

L I

f·~E

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THE

number

this

the

to

move

changing

key

of

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the

graphics

holding

symbol

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used

the

keys.

It

for a mode

on

the

not

made

to

EDIT

:::cPEEf·-i.

and

press

does

not

delete

in

Section 5.

key

in

conjunction

cursor

the

combinations

in

is also

control

cursor

any

characters

halting

control

the

Gml

on

those

conjunction

symbols

used

of

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screen,

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program

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the it

from

functions

anywhere

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control

and

restarting

symbols.

key

will

keys

with

shown

in

conjunction

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l;iiill;lll

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with

on

the

pro-

having

the

on

the

Edit Features

13

with

other

normal, function tion,

and

brackets,

keys

to

upper

case

symbols

[ ],

above

multiplication

and

question

insert

letter

and

delete

display,

the

subtraction

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is

not

as a

group

the

line

the

If

another

the

brought

with

stack

for

top

stack

stack.

a

RESTORE (RES.)

Format: Example:

The

Atari

keeps

track

tional

aexp,

in

the pointer statement

10

20

30

40

50

60

70

00

90

On

the

50

will

Figure

RESTORE [aexp] 100 RESTORE

Personal

ofthe the

program.

to

the

first

permits

FOR

N=1

READ

A

Computer

DATA

RESTORE

Used

with

DATA

repetitive

TO

2

RESTORE READ

B

t·l=A+B

PRIHT 11TOTAL

NE:>\T

N

END DATA

30,15

first print

pass

SUM

Figure

through

4-12.

TOTAL

4-11.

GOSUB

System

statement

the

item

use

optional

on

the

of

the

item

resets

EQUALS 11;M

Restore

the

loop, A

EQUALS

will

60,

Statement

contains

to

that

aexp,

line

specifed

same

Program

be

but

be

read

pointer

the

by

data.

Listing

30

and B will

on

the

With

POP

an

internal

next.

Used

to

RESTORE

the

value

be

second

pass, A

without

the

first

statement

ofthe

30 so

"pointer"

DATA

sets

aexp.

the

total

will

equal15

the

that

op-

item

the

This

line

Program

Statements

21

and

B,

PRINT

because

statement

of

the

in

RESTORE

line

50

will

statement,

display

SUM

will

TOTAL

still

equal

30.

EQUALS

Therefore,

45.

the

TRAP

(T.)

Format: Example:

The

TRAP

an

error

when

an

The

TRAP ecuted, the the that

but

trap

beginning

the message of

the

line

statement

TRAP

aexp

100 TRAP 120

statement

is

detected. Without

error

statement

once

with

another

TRAP

(see

Appendix

where

is

encountered

works

an

error

of

the

section

is

reset

the

error

with

used

has

TRAP

after

B).

256

an

aexp

to

direct

the

program

a TRAP

and

on

been

command.

of

each

displays

any

detected

code

statement,

error

that

This

that

handles

error.

an

and

TRAP

PEEK(195)

*PEEK(187)+ PEEK(186)

occurred.

whose

The value

TRAP

is

from

to

the

error

may

occur

trapped,

command

input

may

32767

a

specified

program

message

after

it

is

from

will

give

will

give

be

cleared

to

line

number

stops

executing

on

the

screen.

it

has

necessary

may

be

the

keyboard

you

the

by

executing

been

placed

an

ex-

to

reset

so

error

number

if

at

65535 (e.g., 40000).

a

22

Program

Statements

5

INPUT/OUTPUT

DEVICES

COMMANDS

This

section

them.

The

commands input/output data

into

the mands geared

The

CLOAD CSAVE DOS ENTER

The

individual system peripheral single symbolic must trol

are

for

commands

hardware

provides

entry

device

be

opened

Block

(IOCB).

describes

devices.

RAM

and

those

associated

generating

described

configuration

manuals

the

devices

point

in

and a device-independent

name

before

From

the

input/output explained The

input

the

devices

output

in

INPUT LOAD LPRINT NOTE

furnished

user

with a single

a (largely)

used

to

access

then

in

commands

with

retrieving

.

this

section

of

each

with

independent

identify

and

each

on,

the

devices

this

section

geared

of

the

each.

it;

must

device

AND

and

how

are

those

are

those

for

accepting data

from

are:

OPEN/CLOSE POINT PRINT PUT/GET

following

The

interface

calling

e.g.,

be

is

Central

to

manner.

sequence.

K:

for assigned referred

devices

the

DEVICES

data

is

moved

that

allow

associated

input. The

RAM

and

READ/DATA SAVE STATUS XIO

is

illustrated

Input/Output

access all

This

means

Each

keyboard.

to

an

Input/Output

to

by

its

access

with

output

the

of

the

device

Each

IOCB

between

getting

devices

(CIO)

system

there

device

number.

to

com-

in

sub-

has

Con-

the

is

a

ATARI System includes variables. IOCB user IOCB IOCB IOCB through 5 are IOCB statements

Keyboard:

converted

Line

characters, a line

Program

device cassette track through

BASIC

the

AT

to

use.

may

not

11'6

for

11'7

is

number

11'7

is

Printer:

Recorder:

which

has

cannot

the

information

command,

ARI BASIC

BASIC

request

input

used

may use.d

in

use,

from

(K:)

(ATASCII)

can

two

be

television

contains 8 blocks

it

needs

buffer

reserves

IOCB

and

output

by

BASIC

also in

opening

it

will

being

performed.

Input

keyboard

(P:)

Output

at a time.

(C:)

be

used

tracks for

recorded

speaker.

sets

for

be

only

Input

length,

up

IOCB

11'0.

The

to

the

referred

the

prevent

device.

data

only

It

recognizes

as

either,

sound

from

in

RAM

which

to

perform

the

ItO

for

GRAPHICS

the

screen.

LPRINT, CLOAD,

to

other

LPRINT

The as

device.

and

Output

and

the

ATARI

buffer

lOCH's,

1/0

as

the

devices

keyboard

each

no

but

never

program

an

address,

but

to

(This

device

or

key

The

control

device.

system,

identifies

I/0

operation.

and

the

user

the

Screen

statement

is

the

and

(or

for

input/output

some

allows

is

pressed.

line

printer

characters.

The

as

both

recording

but

I/0

to

the

This

two

auxiliary

must

specify

Editor,

(see Section

graphics

CSA

VE

commands.

file)

number.

of

the

other

the

user

prints

recorder

Commands

is a simultaneously. purposes.

may

be

Operating

information

control

which

therefore

9)

opens

window

The

IOCB's 1

operations.

BASIC

to

read

ATASCII

read/write

The

audio

played

and

Devic

back

es

the

S:).

If

I/0

the

23

Disk

Drives:

installed, is

attached,

the

(Dt:,

ATARI

there

D2:, D3:,

can

is

no

need

use

D4:)

from

to

Input

and

one

to

four

add a number

Output

disk

after

devices.

drives.

the

symbolic

If

only

16K

of

one

disk

device

RAM is

drive

code

D.

CLOAD

(CLOA.)

Screen

and this position. allows entire record

TV

characters

screen

See

Interface,

face contains a parallel tached.

Format: Examples:

This from to However, structions

Recorder

paragraphs

Editor:

display

device

Reading

the

logical

to

be

Monitor:

addressing

Section 9 for a complete

with

command

cassette

indicate

Manual.

(E:)

(see

TV

causes

user

from

RS-232:

RS-232-compatible

do

for

data from

to

enter

line

transferred

(S:)

Input

and

mechanism.

port

CLOAD CLOAD

100 CLOAD

can

tape

into

that

the

not

press

CLOADing a

under

CHAINING

Input

Monitor)

to

and

within

and

write

(R:)

to

be

used

RAM

PLAY

Steps

and

to

appear

this

device

edit

which

by

CIO

Output

characters

Both

description

The

RS-232

devices

which

in

either

for

button

until

program

for

loading

PROGRAMS

Output

simulate a screen

data.

to

the

execution.

device.

on

the activates

Whenever

the

cursor

the

user

device.

to

text

and

of

device

such

80-column

Direct

needs

after

the

are

oversized

display

the

resides

program.

This

the

display,

graphics

the

graphics

enables

as

printers,

printer

or

Deferred

On

entering

to

be

tape

contained

at

This

device

editing

starting

screen

the

l;ljiil;ill

is

(See Section

device

using

operations

the

terminals,

(ATARI

mode

pressed

has

been

in

the

programs

the

end

uses

terminal.

at

the

editing

key

selected

allows

the

modes.

AT

ARI

system

825TM)

to

load a program

CLOAD,

followed

positioned.

ATARI

are

included

of

this

section.

the

keyboard

Writing

current

process

is

pressed,

as

the

9).

user

cursor

are

supported.

and

plotters.

can

one

bell

by

Specific in-

410

to

cursor

and

the

current

to

read

as

the

to

inter-

It

be

at-

rings

lam

Program

in

the

.

CSAVE

24

I/0

Commands

(CS.)

and

Devices

Format: Examples:

This

command

onto

cassette

ing

CSA VE

be

pressed

tape

has

rather

Notes:

than

Tapes patible

It

CSAVE.

For cue

CSAVE CSAVE 100 CSAVE 100

tape.

two

followed

been

positioned.

a SAVE

saved

may

specific the

cs.

is

usually

CSA

VE

bells

ring

by

li!IBJ. Do

"C"

using

be

necessary

Otherwise,

instructions

tape,

etc.,

used

in

Direct

saves

the

to

indicate

It

is

faster

(see SAVE)

the

two

to

enter

CSAVE

on

see

the

ATARI

mode

to

tokenized

that

not, however,

to

because

commands,

may

how

version

.the

PLAY

save a program

short

an

LPRINT (see

not

work

to

connect

410

Program

save a RAM-resident

ofthe

program.

and

RECORD

press

these

buttons

using

inter-record

SAVE

and

properly.

and

LPRINT)

operate

Recorder

gaps

CSA VE,

Manual.

buttons

this

are

before

the

hardware,

program

On

enter-

must

until

the

command

used

not

com-

using

.

DOS

(DO.)

Format:

Example:

The

DOS

(DOS).

If

puter

will

to

Direct displayed. then

passes

Cartridge)

The

DOS

program.

DOS DOS

command

the

Disk

go

into

mode.

If

To

clear

to

BASIC.

on

the

command

For

more

is

used Operating Memo

Pad

the

Disk

the

DOS

Control

DOS

Menu.

is

usually

details

to

go

from

System

mode

and

Operating

Menu

from

can

also

used

in

on

this,

has

the

System

be

Direct

see

BASIC

not

been

user

the

screen,

returned

mode;

the

Atari

must

has

to

the

booted

press

been

press

to

BASIC

however,

DOS

Disk

Operating

into

memory,

IMMM';!i@!ll

booted,

the

DOS

*'itii#&l;li!Mi.

by

selecting B (Run

it

may

Manual.

be

System

the

com-

to

return

Menu

Control

used

in

is

a

ENTER(E.)

INPUT

(I.)

Format:

Examples:

This

statement

using

LIST (see tokenized) complete, used

with

the

old

program

old

and

new

Format:

Examples:

This

statement

puter

displays

is

usually

information

String are

The which then

If

liiii!Jml,

the

variables

not

allowed.

#aexp

the

input

several

same

type

line

ENTER filespec ENTER ENTER "D:DEMOPR.INS"

form,

it

may

the

programs.

INPUT [ 100 INPUT X

100 INPUT N$ 100 PRINT "ENTER THE VALUE 110 INPUT X

preceded

being

is

data

is

from

strings

the

"C

causes a

Section

and

is

be

run

disk

drive.

from

requests

a?

prompt

by

requested.

are

allowed

optional

is

to

be

the

are

to

cassette

2,

LIST).

interpreted

in

the

Note

memory

This

ENTER

#aexp

{ ; } ] {

keyboard

when

a PRINT

only

and

is

input

(see

screen

be

input

string,

l;i§iii;lll , etc.

by commas.

tape

to

The

program

as

the

normal

that

both

before

statement

data

the

program

statement

if

they

used

to

Input/Output

editor

(E:).

from

play

back a program

data

is

way.

The

LOAD

loading

~~;~

specify

the

}

[,

Of

from

the

encounters

thCJ.t

prompts

are

not

the

Devices).

screen

Arithmetic

originally

is

entered

received.

ENTER

and

CLOAD (see Section 2)

new

is

usually

{

~~~~

X"

user.

subscripted.

file

editor,

in

When

command

one

. ENTER

used

} ... ]

In

execution,

an

INPUT

the

user

or

device

If

no

type

numbers

unprocessed

in

as

Matrix

#aexp

one

can

recorded

the

loading

may

merges

Direct

the

statement.

to

the

variables

number

is

specified,

string,

be

typed

(un-

also

clear

the

mode.

com-

type

from

press

is

be

It

of

on

10

PRWT 11Et-iTER 5 NUt"18EPS

20

FOR

t·~=

1

TO

5

30

I

t·~PUT

::-::

40

C=C+>::

50

NE>::T

t·~

60

70

PR r HT

um

II

THE :::ut

·1

oF

Figure

'/OUP

5-1

Input

TO

BE

SUt·1t·1ED

Nut·1E:ER::: If:

Program

11

II

; c

Listing

I/0

Commands

and Devices

25

LOAD

(LO.)

Format: Example:

This

command

LOAD

uses

long

ized

version

to

specify a number

LOAD filespec LOAD "D1:JANINE.BRY"

is

similar

inter-record

ofthe

to

program.

after

CLOAD

gaps

When

the

"D"

except

on

using

because

the

tape

only

the

full file

(see

CLOAD)

one

disk

default

name

drive, is

disk

system

and

uses

it

is

drive

can

the

not

necessary

#1.

be

used.

token-

LPRINT (LP .)

NOTE

(NO.)

Format: Example:

This

statement

on

the

screen.

device

The entered

Format: Example:

This and current read disk second

specifier

above

command

the

or

written

file (see

file

LPRINT LPRINT "PROGRAM TO CALCULATE 100 LPRINT X;" ";Y;"

program

by

the

NOTE 100 NOTE #1,

current

read

or

POINT).

which

[exp][

causes

the

It

can

be

and

no

user.

To

#aexp,

is

used

byte

number

write

is located.

The

is

then

{ : }

computer

used

in

either

OPEN

or

CLOSE

listing

illustrates a program

print a program

avar,

avar

X,

Y

to

store

the

within

position

in

This

NOTE information used

as

an

exp

... ]

";Z

to

print

Direct

current

the

specified

command

in

index

data

on

or

Deferred

statement.

listing

the

disk

sector

NOTE

into

on

sector

in

file

is

the

X"

the

line

modes.

(BASIC

that

will

the

line

number

the

second

where

used

when

command

first

file.

printer

uses

printer,

the

rather

It

requires

IOCB

add 5 numbers

see

in

the

avar.

This

writing

is

written

#7.)

LIST.

first

data

than

avar

is

the

to

into

no

be

a a

OPEN

(0.)

CLOSE (CL.)

26

J/0

Commands

and

Devices

Formats:

Examples:

Before a a specific trol parameters

#

aexp

device

variables,

OPEN

#aexp,aexp1,aexp2, CLOSE 100 OPEN #2,8,0, 100 A$ = 110 OPEN #2,8,0,A$ 150 CLOSE #2

IOCB

for

Mandatory user.

Reference for m ay

#aexp

can

be

to

the

appropriate

and

passes

the

OPEN

future

be 1 through

"D1:A

accessed,

IOCB

use

"D1:A

TARI800.BAS"

it

any

device-specific

command

character

or

file

(as

in

7.

filespec

T ARI800.BAS"

must

be

opened.

device

handler,

are

defined

that

must

number

CLOSE

command).

This "opening"

initializes

options

be

to

as follows:

entered

same

parameters

any

the

device

by

the

Number

process

CIO-related con-

handler.

links

The

aexp1

aexp2

Code

number

tion.

Code 4

Device-dependent parameter

(see

appropriate

to

8

12

6

9

indicates

determine

input

operation

output

input disk (In

tion.)

end-of-file

also

This

line

operation

and

directory

.

runs

to

trigger

seconds.

the

same

on a diskette

disk

drive

READY.

diskette.

letter

or

on

the

it,

and

the

way

or

door.

A,

type

printer.

is

A

IIO

Commands

and

Devices

31

NOTES

32

Notes

This

section

tions

incorporated

and

returns computational radians functions. or

The

(RAD)

Each

Deferred

following

describes

into

the

result

use.

Included

and

degrees

function

mode.

Multiple

functions

the

arithmetic,

the

ATARI BASIC. A

(usually a number)

in

the

(DEG),

described

functions

and

statements

trigonometric,

trigonometric

that

are

in

this

are

function

for

either a print-out

functions

frequently

section

perfectly

are

described

FUNCTION

LIBRARY

and

special

performs a computation

used

may

be

used

legal.

in

this

are

with

section:

two

in

purpose

or

trigonometri

either

func

additional

statements,

Direct

6

-

c

ARITHMETIC FUNCTIONS

ABS

CLOG

EXP

ABS CLOG EXP INT LOG RND SGN SQR

Format:

Example:

Returns or

negative.

Format: Example:

Returns theses.

Format: Example:

CLOG(O)

ABS(aexp) 100 AB = ABS (-190)

the

absolute

The

CLOG (aexp) 100 C = CLOG(83)

the

logarithm

EXP

100 PRINT EXP(3)

value

returned

should

(aexp)

to give

ATN

cos

SIN DEG/RAD

of a number

value

is

always

the

base

10

an

error

without

of

the

and

CLOG(1)

regard

positive.

variable

ADR FRE PEEK POKE USR

to

or

should

whether

expression

be

0.

it

is

positive

in

paren-

INT

Returns

by

returned digits.

Format: Examples:

the

expression

value

ofe

(approximately

in

parentheses.

is 20.0855365.

INT (aexp) 100 I = INT(3.445) 100 X

=

INT(-

In

some

14.66778)

2.71828283),

In

the

cases

, EXP is

example

accurate

(3

(-15

raised

given

would

to

the

power

above, the

only

to six

be stored

be

stored

Function Li

specified

number

signifi

in

I)

in

X)

brary

cant

33

Returns This

is

Thus,

in

example,

than

or

function

the

true

our

X is

equal

used

greatest

whether

first

example

used

to

-14.66778).

on

calculators

integer the

to

store

less

than

expression

above, I is

the

number-

This

INT

that

simply

or

equal

evaluates

used

to

15

function

truncates

to a

store

(the

to

the

positive

the

first

should

(cuts

value

number

whole

not

off)

of

or

negative

number

be

confused

all

the

expression.

3.

In

the

that

decimal

number.

second

is

less

with

the

places.

LOG

RND

SGN

Format: Example:

Returns LOG(O)

Format: Example:

Returns a hardware-generated returns and

has

be

used. statements like.

Here's a simple

1 0

20

33

Format: Example:

Returns a -1 1

if

aexp

LOG(aexp) 100 L = LOG(67.89/2.57)

the

natural

should

:~~=~~NO(

F.::x:=IHT<

PRINT

give

an

RND(aexp)

10

A=RND

1.

The

variable

no

effect

on

Generally,

or

the

functions

0)

1000:~~:;()

R?i

SGN(aexp)

100 X = SGN(-199}

ifaexp

evaluates

to a

the

routine

logarithm

error

(0)

or

expression numbers RND to

return a number

that

positive

of

the

number

and

LOG(1)

random

in

parentheses

returned.

function

to a negative

is

used

returns a random

number.

should

number

However,

in

for

numbe

or

expression

be

0.

between 0 and

following

the

dummy

combination

games,

number

r;

a 0

decision

(0

is

(-1

would

ifa

exp

in

parentheses.

1,

but

RND is a

variable

with

other

making,

between 0 and

dummy

variabl

be returned)

evaluates

never

dummy

must

BASIC

and

the

999.

e)

to 0,

or

a

s~

TRIGONOMETRIC

FUNCTIONS

ATN

cos

34

Funct

ion

Library

Format:

Example:

Returns

Format: Example:

Returns

Format: Example:

Note:

Presumes

Returns

SQR(aexp) 100 PRINT SQR(100) (10

the

square

ATN(aexp) 100 X = ATN(65)

the

arctangent

COS(aexp)

100 C = COS(X+Y+Z)

the

trigonometric

root

of

the

X,

Y, Z previously

cosine

the

variable

aexp

of

which

or

defined

the

expre

must

expression

!

be

ssion

would

positive.

in

parentheses

in

parentheses.

be printed)

.

SIN

Format: Example:

Note:

SIN(aexp) 100 X = SIN(Y)

Presumes Y previously

defined.

DEGIRAD

SPECIAL PURPOSE FUNCTIONS

ADR

Returns

Format:

Example:

These trigonometric DEG is specified.

to

See

Format: Example:

Returns parentheses. tion

the

trigonometric

DEG RAD 100 DEG 100

two

statements

function

return

to

radians.

Appendix E for

ADR(svar) ADR(A$)

the

decimal

Knowing

to

USR

routines,

RAD

Once

the

memory

etc. (See

sine

of

allow

the

programmer

computations.

the

DEG

statement

additional

address

the

address

USR

the

expression

The

computer

has

been

trigonometric

ofthe

string

enables

and

the

Appendix

in

parentheses.

to

specify

defaults

executed,

functions

specified

programmer

D)

degrees

to

RAD

that

b y

the

to

pass the

or

radians

must

can

be

derived.

expression

informa-

unles

be

for

s

used

in

FRE

PEEK

POKE

Format: Examples:

This

function Direct memory used

within

Format: Examples:

Returns specified teger

between 0 and

tion

(not

a

ran

ge from ROM locat whether location ple,

the

Format: Examples:

FRE(aexp) PRINT FRE (0) 100 IF

returns the

mode

with a dummy

space

remains

a BASIC

PEEK(aexp) 1000 IF PEEK (4000) = 100 PRINT

the

contents

must

be

hexadecimal). The

0 to

ion

s.

PEEK

function

POKE POKE 82, 10 100 POKE 82,

FRE

for

program

of a specified

an

integer

65535

255.

This

In

the

4000

(decimal)

is u

aexp1,

(0)<1000

number

variable

completion

in

"LEFT

or

and

number

function

first

examp

sed

to

aexp2

20

THEN PRINT "MEMORY CRITICAL"

ofbytes

Deferred

MARGIN IS"; PEEK (82)

memory

an

arithmetic

represe

contains

examine

of user

(0)

to

inform

of a program.

mode.

255

THEN

address

nts

the

returned

allows

le

the

above, the

the

RAM

left.

the

programmer

Of

course

PRINT

expression that

memory

will

number

left

location

also

be a decimal

user

to

PEEK is us

margin.

"255"

address in

examine

255.

Its

primary

(aexp).

evaluates to

ed

In

the

Function Li

FRE

The

decimal

integer

either

to second

use

is

how

much

can

also

address

an in-

nota-

with

RAM

determine

exam

brary

in

be

or

-

35

Although

associated

memory aexp1 be

poked. cannot it

is

contents

original

The position

spaces

ti"ti•341;1J1jj

this

with

location

is

the

Note

be

used

advisable

of

contents

above

Direct

of

2 to a

to

the

0

decimal

the

right.

is

not a function,

the

PEEK

or

modifies

address

that

this

number

to

alter

ROM

to

look

at

the

location.

can

be

poked

mode

example

new

position

To

restore

it

function.

data

of

the

locations.

memory

Then,

into

of

the

is

included This

POKE

already

location

is a decimal

In

gaining

location

if

the

POKE

the

location.

changes

10.

In

the

other

margin

in

this

command

stored

to

be

there. In

poked

number

familiarity

with a PEEK

doesn't

left

screen

words,

to

its

normal

section

because

inserts

the

and

aexp2

between 0 and

with

and

write

work

as

anticipated,

margin

the

new

margin

default

it

data

above

is

the

255. POKE

this

command

down

from

its

position,

is closely

into

the

format,

data

to

the the

default

will

be

press

8

USR

Format:

Example:

This

function pression, integer routine These

that to

should

65535. A nearest

These

integer.

values floating the

hardware

direct

control

ture

of

the

USR 100 RESULT =

returns

aexp1,

must

represents

be

performed.

be

non-integer

will

point

number

stack,

of

hardware

(aexp1

[,

the

be

an

the

arithmetic

value

be

converted

format

composed

the

6502

stack.

(Number (High

(Low (High (Low (High (Low

(Low (High

aexp2][,

results

integer

decimal

The

aexp3

USR

(ADD1,A *2)

of a machine-language

or

arithmetic

memory

input

arguments

expressions

may

be

used;

from

to a two-byte

of a group

microprocessor

of

arguments

byte

of

argument

byte

of

argument

byte

of

argument

byte

of

argument

byte

of

argument

byte

of

argument

byte

of

return

byte

of

return

..

.])

subroutine.

expression

address

aexp2,

of

aexp3,

within a decimal

however,

BASIC's

binary of

chip.

on

Binary

number,

RAM

Figure

the

it

memory

6-1

stack-may

X)

Y)

Z)

address)

that

the

machine

range

will

be

Coded

illustrates

The

evaluates

etc.,

are

of 0 through

rounded

Decimal

then

pushed

locations

be

0)

first

to

language

optional.

to

the

(BCD)

onto

under

the

struc-

ex-

an

36

Function

Library

Note:

second,

See Section 11 gramming.

language

programming.

Figure

X is

Z is

for a description

the

argument

the

6-1.

third,

Hardware

etc.

of

Appendix D defines

following

There

the

USR

the

bytes

Stack

Definition

the

address

are N pairs

function

in

RAM available for

of

bytes.

in

machine

the

routine, Y is

language

the

pro-

machine

This

section

Each

string variable together. (including string

and

perly

dimensioned

from 1 to

sioned

length

The

string ASC CHR$

LEN

describes

must

The

the

any

the

functions

be

dimensioned

end

with

individual

Atari

special

substring

(see current of

the

string.

strings

a $. A

characters

keyboard

is

accessible

end

of

string

described

and

the

(see

string

section).

length,

in

this

functions associated

DIM

statement,

itself

is a group

may

be symbols.) A substring in

Atari

BASIC

The

characters

which

section

STR$ VAL

is

less

are:

Section

of

letters, numbers,

if

the

in a string

than

7

STRINGS

with

string

handling.

8)

and

each

string

characters "strung"

or

symbols

or

is a part

string

equal

of a longer

has

been

are

to

the

pro-

indexed

dimen-

ASC

CHR$

Format: Examples:

This

function

string

expression

mode. figure

10

DH1

20

A:f.=11P

30

A=ASC(

40

PF.:H-H

When

executed,

ter

"E".

Note

marks.

Format: Examples:

This

character represented is

returned.

CHR$

functions, ters

of

the

ASC(sexp)

100A

returns

(sexp).

7-1

is a short

A$0::

3)

A$) A

this

that

when

CHR$ (a 100

PRINT

100

A$

string

by

the

In

the

alphabet.

= ASC(A$)

the

AT

This

Figure

program

the

exp)

CHR$ (65)

= CHR$ (65)

function

A TASCII

above

examples,

following

ASCII

function

program

7-1.

ASC

prints

string

code

number(s)

program

code

can

illustrating

Function

a 69

itself

is

returns

the

letter prints

number

be

used

which

u s

ed,

the

in

A is

the

for

the

first

in

either

the

ASC

function.

Program

is

the

AT

ASCII

it

must

be

enclosed

character,

parentheses.

returned.

upper case

character

Direct

code

in

string

Only

one character

Using

the

and

lower

or

Deferred

for

in

quotation

format,

ASC

case

of

the

let-

and

let-

Str-ings

37

10

~'0

I)

30

FOR

I=0

PR I HT

t·~E>=:T

TO

CHfU(

I

25

ASC(

..

A

11

)+I ) )

CHF.:$(

A:

:;C(

"a"

)+

LEN

STR$

Note:

There

Format: Example:

This

function

tion

may variable the

string. Strings

It

is

possible However, was

stored

The

following

10

Dir-1

2~3

A:i=u

3(

1

F'~~ I f

The

result

Format: Example:

Figure

can

be

only

LEN (sexp) 100 PRINT LEN(A$)

returns

then

is

simply

to

the

beginning

(using

routine

A!(

AT

-~T

ofrunning

STR$ (aexp)

A$=

the

be

printed the have a length

store

STO)

10

>

A~~

In

LEt·i<

A$

Figure

STR$(65)

7-2.

ASC

one

STR$

length

or

used

index

for

into

the

of

the

there

previously.

illustrates

>

7-3.

LEN

the

above

and

CHR$

and

in

bytes

later

the

character

ofO

until

middle

string

one

use

Function

program

Program

only

one

CHR$

of

the

designated

in a program.

which

characters

of

the

string

will

contain

of

the

LEN

Example

would

be

Example

in

a logical

string. This

The

is

currently

have

been

by

using

garbage

function:

5.

comparison.

length

at

stored

subscripting.

unless

informa-

of a string

the

end

of

in

them.

something

VAL

38

Strings

This

string parentheses. The would

Note:

F

or

exa

Format: Example:

This string. can

perform

ple

program:

10

20

30 40

from

b e

recognized

There

mple, A=

function

This

is

DH1 B:f.:

II

E:=SG!~\

PRHH

can

VAL(sexp)

100 A = V AL(A$)

returns a number

the

arithmetic operations

8$(5 )

10(10(11!

jB

Figure

number

above

only

STR$(1) > STR$(2) is

opposite

I..JAL(

11

THE

function

example

by

the

be

one

of

B$) )

SQUAPE

7-4.

VAL

computer

STR$

of

a STR$

POOT

Function

returns

would

as a

and

only

not

the

function.

on

strings

OF

the

return

str

one

valid

same

II ,

;8$

Program

string

the

actual

ing

.

CHR$

and

will

value

as

Usi

ng

this

as show n

.;

II IS

form

of

the

number

in

a logical

not

wor

the

number function, the in the

following exam-

II

number

65,

but

comparison.

k cor:rectly.

stored

as

computer

in

it

a

Upon

execution,

It

is

not number, however, number

the

possible

or

1,000,000,000.

to

that

intrepret

use

cannot

screen

the

be

floating

displays

VAL

function

interpreted

point

THE SQUARE ROOT OF

with a string

by

numbers;

the

e.g.,VAL("1E9")would

that

computer

B$

IS

100.

does

not

start

as a number.

return

with

It

can,

a

the

STRING MANIPULATIONS

Strings

rearranged, manipulations.

String

Concatenation string. substring tain can program. In

String

can

Concatenation

Each

up

to 99

be

stored

this

program,

10

D I

t1

:::.'0

A$=

[I

II

30

E:$=

GUIDE

4~3

C$=~~---CHAPTE~:

50

A$(

6£1

A$(

70

F'k:HH

Splitting

be

must

Figure

A$(

II

sr~:

11

IN

Ill

LEt-K

LHK

manipulated

and

sorted.

means

string

characters

in

A$ A$

putting

to

be

dimensioned

another

7-5 is a A$,

B$,

1m;

) ,

8$(

I

~-lGS

::.:

'AT

A~:

I

H 1

)=B$

)+

1

>=C$

A$

Figure

in a variety

The

be

included

(including string

sample

and

100 ) ..

suB:;rp

BA:::IC--A

9.

II

7·5.

String

following

two

or

in a larger

(see

DIM).

spaces).

variable,

program

C$

are

concatenated

C$(

1 (u) )

I

~-iGS

SELF-

Concatenation

of

ways.

paragraphs

more

strings

In

Atari

After

printed,

demonstrating

ARE

o I

TEACHmG

They

can

together

string

is

called a substring. Each

BASIC, a

concatenation,

or

used

and

placed

~:cu:;sE

Example

be

split,

describe

to

substring

in

later

string

in

concatenated, the

different

form

one

large

can

con-

the

substrings

sections

concatenation.

A$.

of

the

The

format

The

svarname

$).

aexp1 dicates of

the greater Figure

string

10

DH1

20

S$="A8CD#"

3e

PRWT

40

END

Result is

(without

of a subscript

indicates

the

ending

substring

than

the

7-6

illustrate

with

an

~:$(

S$(

BCD.

ending

is

used

the

location

is

the

current

ending

5)

2)

location)

string

svarname(aexp1[

to

indicate

starting

of

current

length

a split

Figure

string

location

7·6.

variable

the

location

the

substring.

end

of

indicated.

Split

is

as

,aexp2])

unsubscripted

oft

he If

no

the

string.

the

string. The

with

no

end

10

D m

20

S$=11ATAPI

30

PR

40

END

Result

(with ending

String

follows:

string

substring

aexp2 The

starting

two

location

:::$.::

2~::1

I t·H

S$( 7 ..

is 800.

loc

Examples

variable

and

is

specified,

example

indicated

>

80(1

9 >

ation

name

aexp2

(if

then

location

programs

E:A:::IC

)

(with

used)

in-

the

end

cannot

and a split

11

Strings

be

in

39

String

In

string

with

numbers.

ble

sort.

In

using

assigned

1.

AT values

2.

Upper ters. upper

Comparisons

comparisons,

The

second

logical an

ATASCII

ASCII

and

case

To

operators,

codes

are

letters

obtain

case value,

and

Sorts

the

logical

program

remember

code

number. A few

for

numbers

always

lower

have

the

AT

ASCII code

add

32

operators

lower

to

the

in

Appendix

that

are

sized

than

the

numerical

for a lower

upper

are

used

His a simple

each

letter,

general

in

codes

values

case code.

exactly

rules

order

for

case

number,

apply

of

the

letters

than

letter

the

way

example

and symbol

to

these

numbers'

(see

Appendix

the

lower

if

you

they

are

of

bub-

is

codes:

real

C).

case let-

know the

Note:

memory vary

if a program

Atari

to

BASIC's

make

memory

room

is

modified

for

new

management

statements.

or

Direct

mode

system This

causes

is

used.

moves

the

strings

string

around address

in to

40

Strings

8

An

array

is a one-dimensional

e.g.,

A(O),

A(1), A(2).

8-1

illustrates a 7-element

A

matrix, umns. stored first Figure

Rows by

row

in

BASIC

are

8-2

illustrates

this

run

stored

Subscripts

arra

Figure

context,

horizontally

in

is a two-dimensional

row-ma

first,

followed

a 7 x 4

list

range

y.

8-1.

and

jor

order.

matrix.

of

numb

from 0 to

A(O) A(1) A(2) A(3) A(4) A(S) A(6)

Example

columns

This

by

all

ARRAYS

MATRICES

ers

assigned

of

an

run verticall

means

the

elements

to

subscripted variables

the

dimensioned

Array

table containing

y .

Matrix

that all

the elem

of

the

AND

value.

rows

elements

ents

second

Figure

and

of

row,

col-

are

the

etc

;

.

DIM

(DI.)

This

section strings, and tion

are:

DIM

CLR

Format:

Examples:

M(O,O) M(1,0)

M(2, M(3, M(4,0) M(4,1) M(4,2) M(4,3) M(5, M(6,0) M(6,1) M(6,2)

describes how

to

load

D M {

svar(aexp)

1

mvar(aexp[

DIM A(100) DIM M(6,3) DIM B$(20)

0)

Figure

the

two

both

Columns

M(0,1) M(0,2)

associated

and

}

IJ{

,svar(aexp)

~

,mvar(aexp[

M(1 ,2) M(2,2) M(3,2)

of a Matrix

matrices.

STRINGS

M(1

,1)

M(2,1)

M(3,1)

M(5,1) M(5,2) M(5,3)

8-2.

Example

commands

arrays

,aexp])

used with

M(0,3) M(1,3) M(2,3) M(3,3)

M(6,3)

with

The

,aexp

arrays,

com~a

... ] U

matrices,

nds

in

}tl

and

this sec-

Ana,v

s

and

Matr·ices

41

A DIM

statement

a

string,

a

number

for

for a two-dimensional 20 sioned. gram. there Figure

Note:

matrix

an

array

bytes

Notice

are

The

250

300

310

32f1

array,

in

designated

It

actually 7 elements

8-2

variables elements

orr·1

FOR

A(3

t·E·<T

is

used

or

matrix. A character

an

array

designated

is a

good

in

Figure

is

dimensioned

ATARI

A(

to 0 at to

100

Personal

E==0

>=0

E

takes

array

B$.

habit

0,

use

>

TO

to

reserve a certain

six

bytes.

A .

The

second

(matrix)

All

strings,

to

put

all DIM

8-1

that

although

in

the

as

DIM M(6,3), 28

Computer

the

start

of

the

following

ll1l1

number

in a string

The

first

example

designated

arrays,

statements

the

array

because

locations

does

not

program

oflocations

takes

one

example

reserves 7 rows

M.

and

automatically

execution.

steps:

reserves

The

third

matrices

at

the

beginning

is

dimensioned

of

the 0 element. are

To

in

byte

in

by 4 columns

example

must

reserved.

initialize

memory memory 101 locations

be

of

as DIM A(6),

for

and

reserves

dimenthe

pro-

Although

array

or

array

or

Arrays READIDA T A

"building"

array

10

2f1

3(1

40

50

and

using

DH1

::·::=

FO~:

::-::=:~

A(E

1

of

(1

=:+

60 t·4E>::T

70

FOP

B(l

PF.:H-JT

90

t·~E::-=:T

10

DH1

20

FOR

30

F.:EAD

40

A(E>=>=:

50

PRHiT

60

t·~E::-=:T

70

am

10(1

DATA

matrices

statements

part

of

the

READ/DATA

A<

we>

E=1

TO

1

)=>=:

E

E=1

TO

E..

A(

E

Figure

A(3)

E=l

TO

>=:

A<E

E

33

.. 45.,

an

E >

).,

are

array

9(1

90

8-3.

3

12

"filled"

and

INPUT

using

statements.

Use

of

with

data

commands.

the

FOR/NEXT

by

to

using

Figure

loop

Build

FOR/NEXT

8-3

and

Figure

An

Array

statements,

illustrates

8-4

builds

the

an

42

Arrays and

Matrices

Figure

8-4.

Use

of

R.EAD/DATA

to

Build

An

Array

Figure

10

20

30

40 tl:

50

60

70 :30 90

8-5

shows

Dit·1

FOP

FOF.~

RC!l·J

t·~E~=:T

FO~:

FOF.:

F'P I rH

t·~E:=<T

an

example

t-1( 6 ..

3 >

Pm·l=0

COL=l

F.:Ol·J=O

COL=l

..

COL

t-1<

F.:Ol·J

=

TO

)=I

t·~E>=:T

TO TO

COL : F'P

6

3

tH

(

ROH

6

3

·'

COL

I r·H =

~:t-~D

>

t·~E>=:T

of

building

·:: 0 /~::

F.:O~·l

1

00(1

a 6 x 3

)

matrix.

CLR

Note

that

the

words functions, which with X and Y as

Format: Example:

This and It

also array command.

or

loop

command

matrices

clears is

needed

keyword

function

CLR

200

so

the

Figure

ROW

s.

is first.

the

variable

CLR

clears

the

memory

values

stored

after a CLR

and

They

The

names.

memory

and

in

command,

8-5.

Building A Matrix

COLUMN

are

simply

program

of

variable

undimensioned

are variable

could

all

previously

names

it

must

not

BASIC

names

just

can

var

be

dimensioned

commands,

used

here

as easily have

be

used

for

other

iable

s.

If a matrix,

redimensioned

statement

to

designate

been

strings,

purposes.

string,

with

s,

written

arrays,

or

a DIM

Ar.,.ays

and

Matr·

ice

s

43

NOTES

44

Notes

9

GRAPHICS MODES

GRAPHICS (GR.)

This

section modes create

The

commands

GRAPHICS COLOR DRAWTO

The

PUT/GET

tions

of

Format:

Example:

This

command marizes mand w

hen

code.

The

0 is a full

override

the

GRAPHICS

clearing

To

return

and press l;!jiii;Ui

describes

ofthe

ATARI

graphics

and

the

same

GRAPHICS GRAPHICS 2

is

the

nine automatically printing

text

aexp must

-screen display the split-screen,

the

scre

to

graphics

the

Personal

for

game,

to

be

described

XIO

commands

used

to

modes and

opens

in

the

be

positive,

command.

en .

mode 0 in

AND

Atari

BASIC

Computer.

graphics, and

in

LOCATE

PLOT

POSITION

described

aexp

select

one

the

screen

text window,

rounded

while

modes 1 through 8 are split

add

the

Adding

commands

Using patterns

this

section

explained

in

Section 5.

of

the

nine

characteristics

, S:(the

it

is

to

the

characters

32

prevents

Dir

ect

mode,

COMMANDS

and

the

se

commands,

.

are:

PUT/GET SETCOLOR

XIO

in

this section

graphics

of graphics windo not

nece

nearest

+ 16

to

the

pre

modes.

each. The

ssary

integer. Graphics

the

mode

graphics

ss hiii@l;li@ii

different

are

GRAPHICS

w),

as

to

specify

screen

numb

comma

graphics

it

is

possible

special

Table

applica-

9-1

device

the

displays. To

er (aexp)

nd

or

type

to

sumcom-

116.

So

device

mode

in

from

GR.O

TABLE

Gr.

Mode

0

1

2

3 GRAPHICS 4 GRAPHICS 5 GRAPHICS

6 GRAPHICS

7 GRAPHICS 8

The

following

9.1-TABLE

Mode

Type

TEXT TEXT TEXT

GRAPHICS 320

paragraphs

OF

SCREEN

Horiz.

(Rows)

40 20 20 40 80

80 160 160 80

describe

MODES

FORMAT

Vert.

(Col)

Split

Screen

20

10 20 40 40 80

160

the

nine

AND

Vert.

(Col)

Full

Screen

graphics

Graph

SCREEN

Number

24

12 24

48

48 96 96

192

modes

ic Modes

FORMATS

Of

Colors

.

and Cmnmand.

Required

2

5 513

5 261 4 273 2 537 4 1017 2

4

1/2

RAM

(Bytes)

993

2025

3945

7900

s

45

GRAPHICS

MODEO

This

mode Personal margin ed

by

poking

have

different

by

the

This

full-screen

border

tion,

use

Method

lineno lineno

Method

lineno lineno lineno

lineno

is

the

1-color,

Computer.

settings

background

is

1.

2

at 2 and

LMARGN

margin

display

specified

one

of

the

POSITION aexp1, PRINT

GR.

0 POKE 752,1 COLOR ASC(sexp)

PLOT

GOTO

2-luminance

It

contains a 24

39

allow

and

RMARGN (82

default

color.

Only

has a blue

to

be

another

following

sexp

aexp1,aexp2

lineno

(brightness)

by

40

38

characters

settings. The

the

luminance

display

color).

two

aexp2

To

methods

default

character

and

83). See

color

area

display characters

.

per

ofthe

bordered

screen

line.

Margins

Appendix

characters

Puts cursor

sp

ecified

Specifies Suppresses Specifies character

printed.

Specifies where

character.

Start

loop to prevent

from

being

same

linerw.J

Press

lll1D:I

loop.

mode

for

matrix. The

may

I.

~orne

IS

can

be

in

black

at a specified

at

location

by

aexp1

and

gr

a phics

cur

mode

sor.

to

print

printed. (GOTO

to

terminat

the

AT

ARI

default

be

chang-

syst_ems

determmed

different.

(unless

the

loca-

aexp2.

.

be

READY

e

GRAPHICS

MODES

1AND2

GRAPHICS 0 is also Deferred returns

As are

mod height. of

those

to

display

print

mand.

Example:

The default

Character

Upper Lower Inverse Inverse Numbers

Inverse

mode.

the

screen

defined

in

Table

both

split-screen

e 1 a

re

twice

Characters

in

Graphics characters

characters

default colors depend

color

Table

case case

upper

lower

numbers

in

100 110 PRINT#6;"

and

9-2.

Type

alphabetical alphabetical

case

used

as a clear

It

terminates

to

the

default

9-1,

these

(see

the

width

printed

mode

in

either

the

graphics

GR.

1

color

register

Default

alphabetical

two

Figure

of

in

Graphics

0.

In

the

ATARI"

on

the type

Colors

screen

any

previously

mode

(GRAPHICS 0).

5-color

those printed

the window,

used

modes

9-1)

modes.

mode 2 are

split-screen

text

window

specify

of

character

for

each

for

Color

command

selected

are

Characters

in

Graphics

mode,

or

device

type.

Specific

Register

0

1

2

3

0

2

either

in

graphics

Text

modes.

printed

0,

twice

the

a PRINT

the

graphics window

#6

after

input.

Table

Input

Direct

However,

in

but

are

width

and

command

the

PRINT

9-2

defines

Types

Default

Orange

Light

Dark

Red

Or

ange

Dark

mode

they

Graphics

the same

height is us

com-

Color

Green

Blue

or

and

ed

. To

the

46

Graphic Modes

and

Commands

Note:

See SETCOLOR

to

change

character

colors.

Unless inverse

756,226.

In

graphics

the

rest

(X=Ol

(Y=O)

Figure

otherwise

form.

To

return

modes 1 and

of

the

characters

9-1.

specified, all

print

lower

to

upper

2,

in

Split-Screen

case

case,

there

four

Display

characters

letters

use

POKE

is

no

inverse

different

For

are

and

graphics

756,224.

video,

colors

Graphics

displayed

characters,

but

(see

end

Modes 1 and

in

it is

of

upper

use

possible

section).

case

a

POKE

to

get

S:

Graphics

(graphics

E:

Text

Window

(4

lines)

border

depends individual

TV's

overscan)

2

non-

Window

or

(size

on

all

tt>xt)

GRAPHICS MODES

3,

5,

AND

GRAPHICS MODES

4AND6

GRAPHICS MODE8

7

The X and Y coordinates are

the

numbers

This

split-screen

the

characters

Example:

These

three

state,

but

may Modes 3, 5, plotting,

drawing,

giving a much

These

two

only

two

colors of a two-color it

is

used

when two

modes

Graphics

This takes

mode

graphics

a lot

maximum

of

rows

configuration

+ 16

to

the

GRAPHICS 1 + 16

4-color

and 7 are

be

changed

graphics

alike

and

higher

2-color

while

mode

only

also

resolution.

graphics

the

is

that

two

have a higher

3.

mode

gives

of

RAM

to

obtain

of

one

color

start

at 0 (upper

and

columns

can

mode

number.

modes

to

full

except

positioning

modes

other

modes

it

requires

colors

are

resolution

the

highest

this

and

two

different

left

minus

be

changed

are

also

split-screen

screen

that

by

adding

modes 5 and 7 use

the

cursor;

are

split-screen

can

display 4 and

less RAM

needed

and

which

resolution

kind

of

resolution,

luminances.

of

screen).

1 (see

to a full

the

points

displays

space RAM is

means

of

Table

screen

displays

+ 16

5 colors.

(see

getting

all

the

it

can

The

9-1).

to

the

more

are

and

Table

smaller

other

only

maximum

display

in

by

their

mode

points

smaller,

can

display

The

advantage

9-1).

Therefore,

crowded.

points

modes.

accomodate

values

adding

default

number.

(pixels)

thereby

These

than

As

in

it

a

Graphic Modes

and

Commands

47

COLOR (C.)

Format: Examples:

The

value

of stored mands and nearest ways can

ly

is

usually

in

be

from 0 through

and

its

64

different

in

the

until

integer.

the

color. (The

256-character

COLOR

aexp 110 COLOR ASC("A") 110 COLOR 3

the

expression

display

the

integer

The

different

graphics

in

the

memory

COLOR

statement

from 0 through

display

graphics

modes. In

255 (8 bits)

two

most

significant

characters

are

set.)

COLOR

for

all

subsequent

hardware

and

determines

bits

available

statement

is

executed. The

255.

Non-integers

interprets

text

modes 0 through

determine

in

these

determines

PLOT

the

character

the

modes

the

and

DRA

value

must

are

rounded

this

data

2,

to

color. This

instead

data

WTO

be

positive

in

different

the

number

be

displayed

is

why

of

the

to

com-

to

be

the

on-

full

DRA

WTO

(DR.)

Tables and

modes expression one value pa Table numbers.

Note

9-6

the

character/color

generation

easy

5,5

will

display

Graphics RAM

modes 3 through 8 are

simply

require

or

two

in

the

rticular

9-5,

that GRAPHICS Therefore,

and

determines

in

the

bits

color

graphi

which

Colors

when

command nothing

through 7 when

first

COLOR 1

Fonnat: Example:

This state

PLOT)

(see represents

ur

e 9-1 ). T h e color

Fig

.

DRA 100 DRA

ment caus

to

the X coordinate

PLOT.

9-7

at

the

end

assignment.

of

some

of

the

an

orange A character

the

either 0 or

COLOR

will

register

cs

may

BASIC is

1 (1-bit)

statement may

be

used.)

mode

gives

the

be

changed

which

b e

first

(without

seems

no

WTO

to

COLOR statem e

aexp1, aexp2

WTO

es a line to

the

location

specified

of the

ofthis

color

Table

colors.

not

text

of

and

section

9-2

For

example,

in

graphics

modes,

each

four-color

have a value

The

actual

color

corresponds

ing used .

default

happen

This· may be

colors

by

using

powered

+ 32) is

to PLOT

nt

up,

executed

has bee

10, 8

be draw

and

lin

e is the sam e color

n fr

om the last p o

b y

aexp1

the second

illustrate

the

is a simplified

COLOR

modes 1 or 2 at

so

the

pixel.

Two-color

modes

which

is

displayed

to

the

data

de t e

and

the

SETCOLOR.

the

color

, all

of

and

DRA

n execut

and

aexp2.

represents the

as th e point dis

internal

table

ASC("

data

stored

or

two-luminance

require

greater

0, 1, 2 , than

depends

of

0, 1,

rmin

ed

by

corresponding

data

is

0,

the

pixels

WTO

in

ed. Cor

rec

int display

The

first

¥-coordinate

character

set

which allow

A"):

PLOT

location

in

the

3,

2,

or 3 in

display

or

3.

but

on

5,5.

(The

onl

the the

looking

register

and when

are

set to 0.

GRAPHICS 3

t by

doing

ed

b y a PLOT

expression

(see

played

by the

s

y

in

a

LOCATE (LOC.)

48

Graphic Modes a

nd Commwu

Format: Example:

This

command

th

e graph specified mode

s 0

4-co

lor

m od es. The t w o arithmetic expre

of the

point. LOCATE

is

LOCATE a

exp1, aexp2, va

150 LOCATE 1

ics w

positions

ind

the invisible

ow,

ret r i

arithmetic variable

through

2;

0

or 1 for

is e

POSITION

2,

15, X

eves th

. T

the

quivale

r

graphics

e d at a a t that pixe

his gives a

2-color

number

graphics modes; and

ssion s specify

nt

to:

aexp1

, a

exp

2:GET #6,av

cursor

at

the

specified loc

l, a

nd

from 0 to

th e X a

ar

stor

255

0, 1, 2,

nd

Y coo

es

it

for

Graphics

or 3 for

ation

in

in the

the

rdinates

Doing

a PRINT

the

pixel

which repositioning before LOCATE

doing

command.

10

GF.:AF'H

;2€1

COLOP

30

::;ETCOLOF.: 2 ..

40

PLOT

5€1

DPAl·nO

6ft

LOCATE

70

F'RH-H

the

I

C::;

1

1~3

;:.::

after

was cursor

PRINT.

3+

..

15

_,

12

..

a LOCATE

examined

and

The

16

1

~3,

:3

15

15_,

i<

or

to

putting

following

GET

be

the

from

the

modified.

data

that

program

screen

This was

read,

illustrates

may

cause

problem

back

is

into

the

data

avoided

the

pixel

use

of

in

by

the

PLOT

(PL.)

POSITION

PUT/GET (PU./GE.)

(POS.)

On

execution,

ment

which

Format:

Example:

The

PLOT

command

the

graphics Y-coordinate. luminance change COLOR. mode the Table

Format: Example:

The

at a specified statement until

Formats:

Examples:

this

Points

being

total

number

9-1.

POSITION

can

an

I/0

Figure

the

was

PLOT 100 PLOT 5,5

window.

The

in

the

color

used.

POSITION 100 POSITION

location

be

command

PUT GET 100 200 GET #1, X

9-2.

program

stored

aexp1,

is

color

register,

that

can

The

of

rows

statement

on

used

in

which

#aexp, #aexp,

PUT

#6, ASC("

Example

prints

in

pixel

aexp2

used

in

graphics

The

aexp1 specifies

of

the

register

and

be

plotted

range

of

points

(X-coordinate)

aexp1,

aexp2

8,

12

is

used

the

screen

all modes.

involves

aexp

avar

A")

Program

the

12, 15.

plotted

from

the

on

the

to

place

(usually

Note

Using

data

(1)

determined

modes 3 through 8 to

the

X-coordinate

point

is

the

last

screen

or

the

invisible

precedes

that

screen

COLOR

of

are

at 1

columns

the

color

begins

the

LOCATE

determined

statement

the

plotted

dependent

and

extends

(Y-coordinate)

graphics

a PRINT

cursor

is

issued.

does

by

the

COLOR state-

display a point

and

the

by

the

executed. point, on

the

to

one

window

statement).

not

actually

aexp2

hue

and

use

SET-

graphics

less

than

shown

cursor

This

move

in

the

To

in

In

graphics

ment

works

the

cursor causes The

byte

the

color

GET is tion,

into respond used.)

work,

hand-in-hand

is

moved

the

one-byte

is

either

data

used

to

the

to

the

PUT

to

input

an

AT

(modes

input

the

specified

values

is

used

with

the

ASCII code

3-8).

code

byte

arithmetic

in

the

COLOR

to

output

the

POSITION

location

aexp)

byte

of

the

variable.

statement.

data

to

the

statement.

on

the

screen. Doing

to

be

displayed

for a particular

character

The

displayed

values

(PRINT

Graphic Modes

screen

After a PUT

at

the

character

used

in

and

display.

a PUT

cursor

(modes

at

the

PUT

INPUT

and

This

(or GET),

to

device

position.

0-2)

cursor

and

GET

may

also

Commands

state-

#6

or

posi-

cor-

be

49

Note:

Doing a PRINT

data

in

the reposition doing

the

pixel

the

cursor

PRINT.

after a LOCATE

which

was

and

put

examined

the

data

or

to

that

GET be

modified.

was

from

read,

the

To

back

screen

avoid

into

may

the

this

pixel

cause

the

problem,

before

SETCOLOR (SE.)

Format: Example:

This

statement

in

the

defined

aexp1

aexp2

aexp3

SETCOLOR

100 SETCOLOR 0, 1, 4

specified

below:

=

Color

=

Color Color

higher white.)

TABLE

COLORS

GRAY LIGHT ORANGE RED-ORANGE PINK PURPLE-BLUE BLUE BLUE LIGHT BLUE TURQUOISE GREEN-BLUE GREEN

YELLOW-GREEN ORANGE-GREEN LIGHT ORANGE

ORANGE

is

used

to

color

register.

register hue

number

luminance

the

9.3-THE

(GOLD)

aexp1,

choose

aexp2,

the

The

(0-4

depending

(0-15. See

(must

number,

the

ATARI

NUMBERS

aexp3

particular

parameters

on

Table

be

an

even

brighter

HUE

(SETCOLOR

AND

SETCOLOR

hue

and

of

the

SETCOLOR

graphics

9-3)

number

the

display.

COLORS

luminance

statement

mode)

between 0 and

14

is

almost

COMMAND)

(aexp2)

NUMBERS

0

1

2

3

4

6

7

8

9

10

11 12 13 14 15

to

be

14;

pure

stored

are

the

50

Graphic Modes

and

Commands

Note:

Colors

The

ATARI from 0 through through the these every to because This

tables

No

Although

than

and

COLOR4,

current

RAM

colors.

locations.

television

specify a color

it

specifies

can

be

in

this

SETCOLOR

128

five

can

SETCOLOR

will

vary

display

4.

The

see

The

(The

frame.)

register.

data

confusing,

section

is

commands

different

be

displayed

statement

with

type

hardware

Operating

Appendix

I -

SETCOLOR

OS

transfers

The

SETCOLOR

The

which

so

only

careful

advised.

are

needed

color-luminance

at

any

is

to

specify

and

adjustment

contains

System

Memory

five

(OS)

Locations)

statement

these

values

statement

COLOR

statement

indirectly

experimentation

if

the

default

combinations

one

time.

The

these

five

of

TV

color

has

five

RAM

where

is

used

to

the

requires a value

uses

corresponds

and

set

are

purpose

colors.

or

monitor

registers,

locations

it

change

hardware

different

to a color

study

of

five

possible,

of

the

numbered

keeps

the

from 0 to

of

the

colors

color

used.

(COLORO

track

values

registers

numbers

register.

various

is

used.

not

more

registers

of

in

4

TABLE

9.4-TABLE

OF

SETCOLOR

"DEFAULT"

COLORS*

Set

color

(Color

"DEF

*

Note:

and

A this section

Register)

0

1

2

3

4

AULT"

Colors may

adjustment.

program

10

GPAFHICS

2'€1

~:;ETCOLO

30

PLOT

40

PLOT 19.'

50

PLOT

60

PLOT

70

POKE

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F'P

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occurs

vary

illustrating

is

shown

3

F 0

.~

2

17

..

1 :

DF.'At.JTO

1 :

DRAL·HO

20

..

1 :

D~~AL.JTO

22

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WT

9(1

Defaults

Color

if

not

SETCOLOR

depending

Graphics

below:

_,

B = C

:OL!)P

~.JT

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II

To

2

12

9

4

0

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1 7

..

1 0 :

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AT

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statement

upon

the

1

DPAl·JTO 9 ·' 1 ::

D~:A~·lTO

: I FEF~:~~Gt

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8

10

4 DARK

6

0 BLACK

is

used.

television

the

monitor type,

commands

PINK OR RED

explained

:

30, 18

·

iAL

COi·1P

Color

ORANGE

GREEN

BLUE

condition,

so

far

in

The

SETCOLOR

(see

Table (orange) displayed. sion

ATARI

Note th col

If the and

or

(black).

the

at

program

and

COLOR

9.5).

The

SETCOLOR co

and a luminan

Line

90

PERSONAL COMPUTERS

the

background

is execut

string

expression

ce

of 8 ("norma

suppresses

color

ed , it

in

statements

the

was

will

the text window

mmand

l").

cursor

in

never

print

set

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and

the text

the

the color

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line 100

set

because the

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of

the

ds

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or

regist

next 4 lines plot the

prints

window

logo

in the

as

in

Figure

Graphic

points

er

the

(6

spaces

default

graphics

9-3.

Modes

to

be plotted

0 w i

points

string

in).

is

the desired

and

Commands

th

hue

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window

2

be

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0

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0

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'-'

fl.)

E-

z

...

0

C).

fl.)

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I

...

18 19

10

11

12

13

14 15

16

17

X-AXIS

POINTS

2

0 1

0

1

2

3

4

5

6 7

8

9

1

2

3

4

4 5 6 7 8

3

9

10

11

1213

1415

16

171819,20

ATARI PERSONAL COMPUTERS

(COLUMNS)

2122

23

2425

26

27282930

31

32

33

3435

3637

38 39

DEVICE

(Graphics

/(TEXT

DEVICE

CODE

Screen

Editor

(Text

"S."

or

Text)

WINDOW)

CODE

"E."

Only)

Figure

9-3.

Atari

Logo

Program

Execution

"

~

;:r

c;·

~

;:s

"'

....

g

;3 ;3

;:s

"'

~

"'

Default

Colors

LIGHT

BLUE

DARK

BLUE

BLACK

ORANGE

LIGHT GREEN

BLUE

DARK

RED

BLACK

ORANGE

LIGHT GREEN

BLUE

DARK

BLACK

ORANGE

BLACK

LIGHT GREEN

DARK

BLUE

BLACK

Mode

or

Condition

MODE 0

ALL TEXT WINDOWS

MODES 1

and

2

(Text Modes)

MODES 3, 5,

and

7

(Four-color

Modes)

MODES4

and

6

(Two-color

Modes)

4

MODE8

(1

Color

Luminances)

2

and

TABLE

SETCOLOR

(aexpt)

Register

9.5-MODE,

Color

No.

0 COLOR

1

2

3

4

0

1

2

3

4

0

1

2 3

4

0

1 -

2 3 0

0

1

2 3 4

--

actually

character

-

SETCOLOR, COLOR

Color

(aexp)

data

actually

determines

character

be

plotted

COLOR

data

determines

plotted

1

2 3

- -

0

1

-

1

0

-

to

be

DESCRIPTION

-

Character Background

-

Border

Character Character Character Character Background,

Graphics Graphics Graphics

Graphics

-

Graphics

-

Graphics Graphics

-

Border

~--

TABLE

AND

luminance

Border

point point point

point

(background

point

(background

point

luminance

point

(background

COMMENTS

(same

color

default),

(same

default)

as

background)

Border

color

as

background)

XIO

(X.)

SPECIAL FILL APPLICATION

Format: Example:

This

special

plotted

used

The

1.

2. DRA

3.

4. POSITION

5.

6.

The

that

points

for

aexp1

following

PLOT

bottom

WTO

area

to

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DRA

WTO

POKE

address

This

method

cified

area. The

until

it

reaches a pixel

necessary).

been

filled

will

go

into

which

has

fill

if

this

following the

XIO

XIO 18, 100 XIO 18, #6, 0, 0,

application

happens

command

#aexp,

ofthe

and

lines

with a non-zero

and

aexp2.

steps

illustrate

right

corner

upper

right

filled.

upper

left

corner

cursor

at

lower

765

with

is

used

to fill

fill

starts

This

means

in

with a non-zero

an

infinite

no

non-zero

.

program

creates a shape

draws

aexp1,

XIO

corner

the

each

at

which

that

loop

pixels

aexp2,

"S:"

statement

the

fill

(point 1).

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left

corner

fill

color

horizontal

the

left

contains

fill

cannot

value, as

if

a fill

.

I:I;H!M

in

the

filespec

color

process:

2).

3). (point

data

and

proceeds

be

the

with

or

and

lines

of

fills

an

area

value.

This

outlines

4).

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or

line

from

across

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used

to

change

fill

will

zero

(0)

data

(ifjWI;I@§i

fills it

with a data

the

left

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on

the

Dummy

the

3). top

to

the

data

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stop.

is

attempted

can

bottom

screen

variables

right

bottom

line

wraparound

an

area whi

The

fill

b e

used

(color)

of

between

(0)

edge

of

oft

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to

the

ch h

command

on a line

to

stop

of

3.

the

figure.

are

the

spe-

right

if

as

the

Note

10

GRAF'H

2'0

COLOF.'

30

PLOT

40

D~:A~-H

:-0

[tRA~~JT~J

60

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70

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set.

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the

conversion

Example:

1.

In

Table

2.

Using 32

(114-

I

70;

C!

765

1:::

90

Colors

look

Assign w

9-6,

Table

32 = 82

c:;

5+

3

45

50

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3(t

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10

10,45

.:

3.

, #6, o

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describes

up

the

of

that

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find

9-7,

16

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o.,

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9-4.

To

Characters

the

character

numb

er

SETCOLOR 0

color

is

determin

the

column

locate

column

).

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In

method

numb

required

to

and

4.

"FILL"

Text

Modes 1 and

of

assigning

er

·in

Table

to

ass

lower

case "r"

ed

by

register

number

Conversion

Program

colors

9-6.

ign a co

in

0.

for

" r"

is

the

2

to

the

Then,

see

lor

register

mode

2

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ch a

racter

Atari Table

to

4).

number

character

9-7

to

get

it.

minu

s

54

Graphic

Modes

and

Commands

Table

9.6-INTERNAL

CHARACTER

SET

If

0

1

2

3

4

5

6

7

8

9 )

10

11

12

13

14

15

Column

CHR

Spa

ce

!

"

It

$

%

&;

'

(

*

+

'

-

I

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

If

1

CHR

0

1 33

2

3

4

5

6

7

8

9 41

42

43

'

44

<

-

45

-

46

>

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47

If

32

34

35

36

37

38

39

40

Column

CHR

@

A

B

c

D

E

F

G

H

I

J

K

L

M

N

0

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48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

2

CHR

p

Q

R

s

T

u

v

w

X

y

z

[

\

J

A

-

1.

In

m ode 0 these characte

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64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

Column

CHR

c

G

ll

g

a

Cl

~

Iii

~

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80

81

82

83

84

85

86

87

88

89

.

90

91

92

93

94

95

r s must be precede d w

3

CHR

g

~

=

c c

~

11

~

CD

~

0 D

Q

Cl

Column

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CHR

96

D

97

98

99

100

101 e

102

103

104

105 i

106

107

108

109

110

111 0

ith

an escape,

a

b

c

d

f

g

h

J

k

I

m

n

CHR$(27),

It

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

4

to

CHR

D

CD

<D

CD

b e

p

q

u

v

w

X

y

z

...

-4

~

print

r

s

t

I

ed.

Table

9.7-CHARACTER/COLOR

ASSIGNMENT

MODEO

MODE1

OR

MODE2

zSETCOLOR

SETCOLOR 0

SETCOLOR 1

SETCOLOR 2

SETCOLOR 3

3. POKE

Conversion

2

#+32 #+32

_$32

NONE

#+160

#+128

Z.

Luminance

the

Character

ters

or

special

756,226

POKE

or

CHBAS =

756

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1

POKE

controlled

Base

graphics

226

Conversion

756,224

#+32

#+64

#+160

#+192

by

SETCOLOR

Address

characters

2

1,

0, LUM .

(CHBAS)

; e.g.,

Conversion

#-32

#-64

#+96 #+96

#+64

with

POKE

226

3

to

specify

756,226

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NONE

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NONE

#+128

lower

case

4

let-

To

return

with

to

224.

4. A PRINT "r"

to

SETCOLOR 0

Graphic

These alphabetic design,

Control

characters

keys

pictures,

upper

case

statement

Characters

are

shown

etc.,

letters, numbers,

using

the

converted

in

mode

2 (see

produced

on

back

in

mode 0 and

when

cover.

and

punctuation

number

Table

9-5).

the

&ml

These

characters

in

modes 1 and 2 if

(82)

assigns

key is

CHBAS

marks

, POKE CHBAS

the

pressed

can

be

lower

used

is

changed

with

to

case

the

draw

.

56

Graph

ic

Mod

es

and Commands

10

SOUND (SO.)

This

section through can

be

"played"

also

be

fects.

The

used

to

tions

allow

games,

The

SOUND

Format:

Example:

The

statement

counters

This

etc.

command

SOUND

command

describes

the

audio

used

to

other

manipulate

these

and

SOUND

100 SOUND 2, 204, 10, 12

statement

is

executed.

another

the

statement

system

simultaneously

simulate

commands

controllers

SOUND

can

ofthe

explosions,

the

keyboard,

functions

PADDLE

PTRIG

aexp1,

causes

The

statement

be

used

SOUNDS

CONTROLLERS

used

to

generate

television

creating

described

joystick,

to

be

plugged

covered

aexp2,

the

specified

note

will

in

either

harmony.

whistles,

in

this

aexp3,

continue

with

Direct

monitor.

this

and in

and

section

aexp4

note

the

same

or

AND

musical

Up

to

This

and

other

section

paddle

playing

Deferred

to

deal

controllers.

used

are:

STICK STRIG

begin

aexp1

GAME

notes

four

different

SOUND

interesting

with

in

BASIC

playing

until

the

or

an

END

modes.

and

sounds sounds

statement

sound

the

functions

These

programs

as

soon

program

statement.

can

func-

as

ef-

for

the

en-

The

aexp1

aexp2

aexp3

aexp4

SOUND

=

parameters

Voice.

ment.

Pitch.

the

lower

various

one

octavf'

Distortion. Can

sound gives

an

a

race

with

the

value

of volume special effects,

Volume control. Can

barely mal.

If

should

are

described

Can

be

0-3,

but

Can

be

any

the

pitch.

musical

effects. A 10 is

interesting

track)

1 is (see aexp4).

audible more

not

notes

below

be

can

be

distortion

used

to

noise

whereas

than 1 sound

exceed

middle

32.

each

number

Table

ranging

C.

even

numbers

used

buzzer

produced

value

(aexp3)

force

output

The

rest

generation,

be

between 1 and

a 15 is

statement

This

will

as follows:

voice

requires a separate

between

10-1

to

sound. A buzzing

using

0-255.

defines

from

created a "pure"

to

of

and

loud. A value

create

the

two octaves

between

two

separate

alternating

the

speaker

the

numbers

experimental

15.

is

being

an

unpleasant

Sounds

Using

The

larger

pitch

numbers

above

0-14.

Used

tone

sound

(like

SOUND

between 0 and

using

are

used

use.

a 1

creates a sound

of

B is

considered

used,

the

"clipped"

and

Game Controllers

SOUND state-

the

number,

for

the

middle C to

in

creating

whereas a 12

engines

commands

the

for

total

at

1.

A

specified

other

nor-

volume

tone.

57

Using

the

note

write a program

values

that

in

will

Table

"play"

10-1,

the

following

C scale.

example

demonstrates

how

to

TABLE

HIGH

NOTES

MIDDLE C

LOW

NOTES

10

F.:EAD

20

IF

30

SOUr·iD

40

FOP

50

PRWT

60

GOTO

70

END

80

DATA

191.·

90

[lATA

Note

that

designated

10.1.

A=256

~·J=1

96.:

the

range.

A

~3

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A

10

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108.:

12:3.~

DATA

TABLE

~

iHEt·i

A

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1

(1

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1 0

TO

400:

31.·

35,

121

144.~162

Figure

statement

The

256 is

OF PITCH

NOTES

c

B A#

orB~

A

G#

or

A~

G

F#

or

G~

F E

orE

D# D

or

D~

C#

c

B A#

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G#

or

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G F#

or

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45

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1:::2.~

193.:217)243

10-1.

Musical

in

line

used

as

VALUES

..

53

..

6(1, 64,

80

ends

an

end-of-data

72

..

Scale

Program

with a 256,

FOR

29

31 33 35

37 40 42 45 47

50

53

57

60 64

68

72

76

81

85

91

96

102

108

114

121

128

136

144

153

162

173

182

193 204

217 230

243

·'

:31

256

marker.

THE

which

MUSICAL

is

outside

ofthe

58

Sounds

and

Game Controllers

GAME CONTROLLER

FUNCTIONS

Figure sonal sonal fed

directly

10-2 is

an

Computers.

Computer

to

the

illustration

The

controllers

or

to

external

computer

of

the

three

can

mechanical

for

processing

controllers

be

attached

devices

and

used

directly

so

that

control

with

the

to

the

outside

purposes.

Atari Atari

events

can

PerPer-

be

PADDLE

PTRIG

STICK

Format: Example:

This

function controllers other

functions

controls,

"PADDLE

etc.

ween 1 and

troller

Format: Example:

The

is

rotated

PTRIG

controller

number

Format:

Example:

This used 0-3

between 0 and 7 as

function

with

from

left to

Figure

P ADDLE(aexp) PRINT P ADDLE(3)

returns

are

For

ACTIVE."

228,

the

numbered

or

commands

example,

with

the

status

0-7

Note

counterclockwise

PTRIG(aexp) 100

IF

PTRIG(4)"'0 THEN PRINT "MISSILES FIRED!"

function

is

pressed. Otherwise,

returns a status

STICK(aexp) 100 PRINT

works

the

joystick

STICK(3)

exactly

controller.

right.

10-2.

Game

of a particular

from

left

to

"cause"

the

statement

that

the

number

(turned

it

designates

the

same

The

Controller Controller Controller Controller

Controllers

numbered

to

right.

This

further

IF

PADDLE(3) = 14

PADDLE

increasing

ofO

to

ifthe

function

in

the

trigger

returns a value

the

controller.

way

as

the

PADDLE

joystick

1 =

controllers

STICK(O) 2 = STICK(l) 3

==

STICK(2) 4 =

STICK(3)

controller.

function

actions

like

returns a number

size

as

the

left).

button

of

1.

The

command,

are

The

can

be

sound,

THEN

knob

on

ofthe

designated

aexp

numbered

paddle

used

with

graphics

PRINT

the

must

but

can

from

bet-

con-

be

a

Figure

troller

10-3

is

moved

shows

in

the any

numbers

direction.

that

will

be

returned

Sounds

when

the

and

Game Controllers

joystick

con-

59

14

13

STRIG

Fonnat: Example:

The

STRIG

with

both

Figure

STRIG(aexp) 100

IF

function

the

joystick

10-3.

Joystick

STRIG(3) = 0

works the

and key

Controller

THEN

PRINT " FIRE TORPEDO"

same

way

as

the

board controller

Movement

PTRIG

s.

function

.

It

can

be

used

GO

Sound.s

a nd Gam e

Contro

llers

11

MEMORY

CONSERVATION

ADVANCED

This

section

memory,

grams.

processor language.

a

careful

These

hints grams necessary

1.

less

In

many characters true Statements were conventional keywords

and

This

chip

An

study

due

of

used

the

includes

combining

section

nor

additional

of

Atari's

give

ways

readable

to

memory

small

as

they

ATARI

are

on

program

typewriter)

and

hints

machine

does

not

does

it

purchase

Assembler

of

conserving

and

harder

limitations.

computers,

are

typed

Personal

always

variable

displayed

on

increasing

include

give

eliminating

into

Computer

entry.

between

names.

PROGRAMMING

TECHNIQUES

programming

language

an

instructions

of

the

Atari

Editor

memory

to

modify,

the

keyboard

System,

the

same

Spaces

Here

should

successive

is

programs

instruction

on

Assembler

Manual

. Some but

there

blank

regardless

be

an

example:

efficiency,

with

set

for

programming

Editor

are

strongly

ofthese

are

cases

spaces

will

which

between

save

removes

of

used

Gust as

keywords

memory. This

Atari

the

6502

in

cartridge*

recommended

methods

where

extra

how

many

in

and

conserving BASIC

words

typing

micro-

machine

make

this

is

spaces.

spaces

between

pro-

and

pro-

and

not

on

.

is

a

Note

the cases, a spaces

2. Each " logical used

to colon bytes.

*Available

space

statement

are

left

new

line

line".

full

(:)

to

late

between

out,

number

Each

capacity

separate

1980.

10

will

but

logical

or

each

IF A

IF

and A and

be

interpreted

this

is

represents

line

not.

Adding

pair

5 THEN PRINT A

between

correctly

not

always

takes

of

statements

the

beginning

6 b ytes

an

additional

true.

of "overhead

on

Advanced Programming Techniques

THEN

by

the

Use

conventional

of

what

BASIC the

same

and

PRINT.

computer

is

called a new

" ,

whether

statement

line

takes

In

most

even

if

spacing.

it

by

using

only

all

is

a 3

61

If

10

20

3e

40

5e

and

10

This

3.

Variables constant variable But its twice used

you

need

to

save

>{='r'+1

V=Y+1

Z=X+"i'

PRI~H

GOTO

consolidate

>::=:~+l:Y='l+1:2=::·::+'-f

each

length.

Z

53

lines

consolidation saves

and

constants

(4,5,16,3.14159, etc.) is used,

requires 8 bytes

time

it

is

Thus,

in a program,

throughout

memory,

like

this:

:

PRINT

12

bytes.

should

plus

used

after

if a constant

it

the

being

should

program.

avoid

programs

Z:GOTO

be

"managed"

the

length

defined,

(such as 3.14159) is

be

defined

For

example:

10

it

takes 7 bytes.

of

the

it

takes

as a variable,

like

this:

for

savings,

variable

only 1 byte,

used

too. Each

Defining a new

name

(in characters).

regardless

more

than

and

the

variable

time

once

name

a

of

or

10

PI=3 .

20

PRINT

SQUARED T It1ES

4. Literal (including

5.

String (including ofthe Obviously,

6. Definition variable size umns). mately times

strings

variables

string

name

of

the

Thus,

3 (for

100 (the

14159

"AREA

all spaces)

spaces)

itself(1

the

of a new

matrix

OF

II

require 2 bytes

take 9 bytes

plus

byte

use

of

matrix

plus

the

(product

a 25

row

variable

matrix

A

CIRCLE

i

pI

in

the

string.

the

space

per

string

requires

space

of

by 4 column

name) + approximately

size),

or

IS

overhead

each

plus

eaten

character,

variables

15

needed

the

number

about

for

630

THE

the

up

by

including

is

very

bytes

the

matrix

bytes.

RADIUS

and 1 byte

length

the

plus

DIM

of

would 10

costly

rows

of

DIM

statement

spaces)

in

the

statement

and

require

(for

the

for

the

when

terms

length

plus 6 times

the

DIM

each

character

variable

plus

the

it is

defined.

of

RAM.

of

the

number

15 +

approxi-

statement)

name

size

matrix

the

of

col-

+ 6

82

Advanced Programming Techniques

7. Each

8.

9.

character people remove

Subroutines take hand, a subroutine and·

Parentheses cases However, precedence

trying

remark

less

memory

RETURN

if

they

after

REM

takes

to

understand a program,

statements

can

save

memory

than

duplicating

that

is

only

statements.

take

one

byte

make

an

expression

removing

will

unnecessary

same a few

to

save

because

each.

bytes.

one

byte

memory.

called

Extra

more

parentheses

of

memory.

but

sometimes

one

subroutine

the

code

several

once

takes

parentheses

understandable

extra

are

and

Remarks

it

and

several

times.

bytes

a good to

the

relying

are

helpful

is

necessary

short

On

the

for

the

GOSUB

idea

in

programmer

on

operator

to to

calls

other

some

.

PROGRAMMING

IN

MACHINE

LANGUAGE

Machine

puter subroutines entered

Before it cumulator the ped

The (decimal), struction. in format

The

subroutine

array

The decimal decimal language routine.)

language

contains

into a program

returns

stack.

off

the

subroutine

locations 212

to

ADR

function may

or

string,

following

codes, co

number

is

a 6502

from

BASIC

to

(PLA)

instruction

If

this

number

stack

also

should

and

then

The

BASIC

and

obtain

subroutine.

in

machine

program,

the

and

nverting

into

written

microprocessor

BASIC,

return

interpreter

213

value

then

entirely

using

the

by

hand

the

to

remove

is

not

0,

using

PLA. (See

end

by

placing

to

BASIC

into

an

returned

be

used

to

language. Use

use

this

Hexcode Loader,

each

hexadecimal

an

array.

(An

array

in

binary

and

USR

assembly

the

then

all

Figure

the

using

will

convert

integer

by

the

pass

data

the

address

The

array

is

used

code.

The

AT

it

is possible to call 6502

function. Short

(if

necessary).

language

number

ofthe

input

6-1).

low

byte

an

RTS

the

2-byte

between 0 and

USR

function.

that

is

stored

ADR

function

as

one

of

provides

number

is

then

to

allocate space

routine

(N)

of

arguments

of

its

(Return

binary

65535

in

to

the

USR

the

means

to

decimal,

executed

routines may

get

ARI

must

input

result

from

arrays

the

input

of

in

Personal

machine

then

do a pull

arguments

must

be

in

location 212 Subroutine) number

in

floating-point

or

strings

address

arguments.

entering

and

storing

as

an

assembly

memory

for

Com-

code

be

ac-

off

pop-

in-

stored

to

of

the

hexa-

the

a

Advanced Programming Techniques

63

1. To use

disk

or

10

GRAPHICS RAI'1" 20

REM

A~t

A,

S'

AT 21

REM

30

REM

0

OUTPUT

31

REM

SR

STATEMENT.

43

DIM

50

REM

60

N=0 = PRWT

ONE

70

INPUT 89

IF 90

FOR

100

:~

I } I ) ) = 110 120 13£1 140 150 190

200 210 220 230

240 250 260 300 ES

IH

999

1000 1910

)

1030 1940 1050 1060 1970

LLO~~S

this

program,

cassette

for

0,

future

PRINT

=PRINT

STORES

OUTPUTS

LI~E

USEJ;.:

REST

A<

INPUT,COt·MEF.:~3IOt

NUMBER

TI-H~

LINE,

OF

50)..

HE:)=:$(

OECit1AL

IN

HITS

BASIC

"Et-HER

IS

IN}

EtHEF.:

1·£:=0::$

HE:~=

II

DONE

1=1

TO

LEW

IF

HE:~<

I,

I ){="9"

GOTO

120

N=~t=n6+ASC<

NE'I.T

I

PRit·IT

A<

C

)=N

IF

N<>999

REM

PRHIT

GRAPHICS

HE:);:$(

H =

C=C+1

THEN

OUT

0=PRINT 111500

c=e

C=C+1

IF

A< C )=999

PRINT A<C GOTO PRIHT

f'E1

A(

C);

II}

)=0

220

"PUT

CORRECT

Lit·E

1000.

:r.~

E>;ECUT

CLR : BYTES=0 TRAP

390:

DIM

FOR

I=l

TO

READ

A=

IF

A>255

POKE

ADR<E$)+J,A

NE:>n

I

REM

BASIC

PART

first

enter

it.

After

entering

use.

"rE:~~CODE

LOADER

EQUILIALHHS

PRINTED • DATA

STAT8·1ENT

1500.

PLACES

CURSOR

ON

"RETURHu, ~ ENTERS

PROGRAM

IOCLUDING

5)

·

V:;TORAGE

1

1-1)::

CODE

. IF

I

DOHE

I •

II;

II

THEN

N=999:

HE:~{$>

H£t-~

L I> >-Asu

GOTO

DATA

LWE

THEt-~

PRHH

II;

t-UMBER

":STOP : REt1

I

Ot~

MODULE

E$(

1 ),

GOTO

N=t-t=~16+UAL<

11

60

AT

DATA

"999

OF

TRAP

:f.::;::

E( I NT<:

8\'TES . ...-6

A"

1500

11

B'lTES

TI·El~

GOTO

1060

OF

USER

Is

P~:OI;RAt1

PROG

IN

ARR

PR

It·ITE

OF

DATA.

LAST

130

>+10

;

:STOP

HE:=< BYT LmE

)+1

it, save

U

HE

FO

this

program

on

64

Advanced

Programming

Techniques

Figure

11-1.

He.-rcode

Loader

Input

Program

2.

Now

add

cluding

example

3.

Count line

1000

replace

4 .

Run

the subroutine DONE

5.

Now

the

program

pressed.

6.

Add a program

hexcode using

CSA

the

program

routine

(ftii@l;li!+ii

reload

the

below.)

the

total when

it.

program

and

DATA

loader

VE

may

the

BASIC

USR

function

number

requested.

pressing

press

IDiiJ.

line

until

line

through

or

SAVE.

containing

cause

.

If

the

program,

language

and

1Di1J

(1500)

the

5 GOTO 1000 to

the

system

and

that

of

hex

If

enter

displays

cursor

line

It

is

important

the

system

doe

correct

part

calls

codes another

the after

is

260).

USR

to

sn 't

of

your

program

the

machine

to

be

entered

number

hexadecimal

each

entry. After

on

the

screen.

moved

calL A

crash.

it.

to

bypass

Now

save

to

do

If

respond,

mistake

the

this

the

turn

starting

language

and

enter

is

already

codes

of

It

will

DATA

hexcode

the

completed

before

in a machine

system

power

at

subroutine.

this

entered,

the

machine

the

last

not

be

line

and

loader

(or

executing

does

hang up,

off

and

line

1080 in-

number

simply

entry,

entered

fiiiim

delete

program

the

part

language

on

again,

(See

on

level

type

into

is

the

by

of

press

Note:

The

following Loader machine BASIC

1980 1090 1100 1110 1120 1130 1140 1150

1160

After

entering

Type

RUN

This

method

program.

program

graphics

GRAPHICS FOR PRIHT

PF~INT

PRIHT PRIHT

NE:)::T

Q=USR( FOR

liimmJ.

two

The

changes

design,

I=1

#6j

#6;

#6.:

I

ADR<

I=1

this

program,

only

sample

first

then

1+16

TO

11

t10t.hir.s

11

t~OTHH~

11

not.hins

11

NOTHit·~

E$

TO

works

with

programs

program

the

colors.

changes

6

is

IS ls IS

)+

1 )

25: t·

E=<T

I =

check

that

1000 CLR:BYTES

relocatable

can

each

prints

colors.

The

second

1v1

t"II0

in::t!

t10UH~G!

1

mo

...

•ins!

t101...!H~G!

GOTO

line

NOTHING

1150

1000 reads:

= 21

machine

be

entered

sample

11

II

11

II

language

into the

IS

MOVING

program

routines.

Hexcode

while

displays

the

a

Ad

vanced

Progra

mmin

g Techn

iqu

es

65

Now

enter

the

hexadecimal

codes

as

shown

column

by

column.

When

completed,

last

entry

Now

run

has

been

5.

The

second

NOTHING

line

1000.

1080 1090 110(1 1110 1120 1130 1140 115(1 1160 117(1 1180 1190 1200 121(1 1220

68

A2

0

AC

C4

2

BD

cs

2

9D

C4

type

(999)

on

the

program

added,

type

RUN

program,

IS

MOVING

Follow

steps 2 through

GRAPHICS

SET

COLO~~

SETCOLOF.: SETCOLOR

CR=1

FOR

::-::=0

TO

COLOR

PLOT

~AL·JTO

CR=CR+0

IF

NE:x:T

:~=US~'(

FOR

GOTO

INT<

801

:;

CR=4

:<

ADR(

1=1

1200

0

::

..

.

125

THEN

TO

DONE

and

DATA

by

line

typing

lilll!lmJ.

which

program. Be

follows,

7+16

€L

91

4

L 9 ..

E:

2~9~4

159

CR)

95

CR=1

E$

)+

1 )

15=N£:;::T

2

E8

EO

3

90

F5 8C C7

2

60

press

&mJ.

and

pressiDmJ.

GOTO 1000

Press

illil1tito

should

sure

to

check

6.

I

Now

and

place

pressing

stop

be

entered

the

BYTES =

BYTES=

the

l;liilll;!ll,

program

cursor

and

in

place

__

21

after

or

if

delete

of

count

the

line

5

the

in

66

Advanced

Type

Enter

Programming Techniques

RUN

lim!liJ3

the

hexadecimal

68

A2

AC

C4

BD

C5

9D

-

CA

codes

for

this

program

2

E8

0

2

EO

2 90 F5

8C C6

2

60

column

by

column.

BYTES=

21

When

completed,

last

entry

Now

run

the

GOTO 1000

5.

(999)

program

and

on

type

the

RUN

DONE

DATA

by

typing

lilii!lmJ.

and

press

line

and

GOTO 1000

Press

lilii!lmJ.

press

lilii!lmJ.

and

l!m!!:l

Now

pressing

to

stop

place

limml3,or

program

the

cursor

and

after

add

delete

line

the

5

Address

02C4

02C5 02C6 02C7

6000 68 6001 6003 6006 6009 600C

600D

600F

6011 8CC602 6014 60

Object

Code

A200 ACC402 BDC502

9DC402

E8

E002

90F5

Figure

might

prove

Assembler

Line

No.

0100 0110 0120 0130 0140

0150 0160 0170 0175 0180 0190 0200 0210 0220 0230

0240 0250 0260

0270

0280 0290

Label

11-2

LOOP

illustrates

useful.

It

an

is

included

Subroutine

Mnemonic

*= PLA LDX LDY

LDA COLOR1,X

STA

INX

CPX

BCC

STY RTS

assembler

to

COLORO

COLORO,X

COLOR3

subroutine

here

Rotate

Data

$6000

110

113

LOOP Loop

used

for

the

information

Colors

Routine From

4

Operating COLOR 0 = $02C4

COLOR 1 = $02C5 COLOR 2 = $02C6 COLOR 3 = $02C7

Machine

Pop

Zero

Save COLOR 0

Increment

Compare

with

less Save COLOR 0 Return routine

..

to

one

colors

are

stack

the X register

2

if X register

than

from

to

rotate

of

rotate

register

rotated.

system

program

(See

Chapter

the

X re.e;ister (add

contents

2

in

machine

colors

the

user.

COLOR

address

starting

contents

COLOR 3

data

to

another.

address*

4)

of X register

level

which

one)

are

sub-

Assembler

Prints

11

Indicates Routine

*

$

Indicates a hexadecimal

This

data

(source)

is

relocatable

number

Figure

This

11-2.

Portion

is

Using

Assembler

Source

Information

Atari

Subroutine

Assembler

To

Programmer

Cartridge

Rotate

Advanced Programming Techniques

Enters

Colors

67

APPENDIX

A

ALPHABETICAL DIRECTORY

Note:

The

period

RESERVED

WORD:

ABS

ADR

AND

ASC

ATN

BYE

OF BASIC RESERVED

is

mandatory

ABBREVIATION:

after

B.

all

abbreviated key

word

Function va

riable

Function

Logical oper a pressions

String string

Function sion

Exit system

returns abs

or e

returns

joined

function

character.

returns

in

radi

from

BASIC

or

console

s.

BRIEF

OF

BASIC

xpr

essio

tor:

by

returns the

an s

or

SUMMARY

STATEMENT

olute

n.

memory

Expression

the

deg

and

processor

address

AND

are

arctangent

r ees.

return

WORDS

value

is

numeric value

.

(unsigned) of

of

a s

true only if

true.

of a number

to

the res

tring.

ident

the

both subex-

of a single

or

expres-

operating

CLOAD

CHR$

CLOG

CLOSE

CLR

COLOR

COM

CONT

cos

CSAVE

CLOA.

CL.

c.

CON.

data

from

Loads

String to a numeri

Function sio

I/0 operations.

The opposite matrices.

Chooses co work

Sa

Continue. Causes a next ing

Function sion

Outpu tape

function

n.

statement

.

me

as DIM.

line

a

STOP

(degrees

ts data f

storage.

returns

following

returns

Program

returns a single

c v

alu

used

of

lor reg

.

or

radians).

rom

e b e

twe

the

base

to

close a file

DIM:

ist

er

program

use

the

cosine

RAM

Recorder

en 0

and 255

10

logarithm

Undimension

to

b e used

to

of

restart

the

i·l;it!M key

of

to the Prog

string

at

the

into

RAM.

byte

in

AT

of

conclusion

s a ll

in

color

execution

or

variable

ram Rec

equivalent

ASC

II

cod

an

expres-

of

string

graphi

on

encounter-

or

expre

ord

er for

e.

I/0

s;

cs

the

s-

Ap

pendix

A-1

RESERVED

WORD:

DATA

ABBREVIATION:

D.

Part

ofREAD/DATA

succeeding

individual

as

BRIEF

OF

items

data

BASIC

combination.

(which

items.

SUMMARY

STATEMENT

be

separated

Used

must

to

identify

by

the

commas)

DEG

DIM

DOS

DRAWTO

END

ENTER

EXP

FOR

FRE

DE.

DI.

DO.

DR.

E.

F.

Statement trigonometric (Default

Reserves array, must

be

Reserved be

displayed.

DEG

functions

in

radians.)

the

specified

or

string.

dimensioned

word

for

(See

Draws a straight

specified

Stops

Program

may

I/0

tokenized

Function

point.

program

may

be

used

command

(source)

returns

execution; closes files;

be

more

used

power.

Used

with troduces during

Function memory

range

the

execution

returns

(in bytes).

tells

computer

in

degrees

amount

All

string

variables,

with a DIM

disk

operators.

DOS

Manual.)

line

between a plotted

restarted

than

to

using

once

store

form.

e (2.7182818)

to

establish

that

the

loop

of

loop.

the

amount

to

instead

of

memory

arrays,

statement.

Causes

turns

CONT. (Note:

in a program.)

data

or

programs

raised

to

FOR/NEXT

variable

of

remaining

will

perform

of

for

matrices

the

point

off

the

specified

loops. In-

operate

radians.

matrix,

menu

and

sounds.

END

in

un-

user

to

in

GET

GOSUB

GOTO

GRAPHICS

.

INPUT

INT

LEN

A-2

Appendix

IF

GE.

GOS.

G.

GR.

I.

Used

mostly

of

data.

Branch

with

to a

subroutine

number.

Unconditional

Specifies used. GR.O

Used another pression

Causes ecution inputting

Function the even

String ing

which

may

to

cause conditional

statement

is

true).

computer

continues

data.

returns

specified value.

when

number

function

in

bytes

or

disk

branch

of

be

on

to

only

the

to

the

used

the

ask

when

next Rounding

is negative.

returns

characters

operations

beginning

a specified

eight

graphics

to

clear

branching

same

line (only

for

input

i;i§ii@l

lowest

the

length

(1

byte

to

input

at

line

the

number.

modes

a single

specified

byte

line

is to

screen.

or

to

execute

ifthe

first ex-

from

keyboard.

key

is

whole

is

always

of

integer

the

pressed

specified

downward,

after

below

contains 1 character).

be

Ex-

str-

RESERVED

WORD:

ABBREVIATION:

BRIEF

OF

BASIC

SUMMARY

STATEMENT

LET

LIST

LOAD

LOCATE

LOG

LPRINT

NEW

NOTE

ON

LE.

L.

LO.

LOC.

LP.

N.

NO.

Assigns a value tional

in

Atari

BASIC,

Display

Input

or

from

otherwise

disk,

Graphics: Stores, controls

Function

Command

Erases all

Causes a defending Al

A " it is

See DOSIFMS

Used Multiple depending

loops

1"

is

true,

with

a specified

returns

to

line

contents

FOR/NEXT

on

the

are

executed

returned

a

"0"

Manual

GOTO

branches

on

the

sion.

to

a specific

output

etc.

into

in

a specified

graphics

the

natural

printer

of

particular

only

is

returned.

...

or

to

different

value

and

may

the

to

print

user

RAM.

loop

at

least

if

the

used

only

GOSUB

of

the

variable

be

simply

the

program

computer.

variable,

point.

logarithm

the

specified message.

to

terminate

variables

once

.

expression

in

disk

for

branching

line

numbers

ON

variable

name.

LET is op-

omitted.

list.

the

value

of a number.

or

continue

or

expressions.

is NOT

operations.

purposes.

are

possible

or

that

true.

expres-

If

OPEN

OR

PADDLE

PEEK

PLOT

POINT

POKE

POP

POSITION

PRINT

POK.

POS.

PR.

o.

PL.

P.

or?

Opens

the

Logical either

one

if

both

are

Function

Function memory

Causes a

specified.

Used

with

Insert

the

tion

. May

ROM

or

Removes when

departure

normal

Sets

the

I/0

command

specified

specified file for

operator

is

true,

used

a

"1"

false.

returns

position

decimal

location (RAM

single

point

disk

operations

specified

be

you'll

the

byte

used

only

get

an

loop variable

from

manner.

cursor

to

the

causes

output

device.

input

between

is evaluated. A

of

the

paddle

form

or

ROM).

to

be

plotted

only.

into

the

with

RAM.

error.

from

the

loop is

specified

output

screen

from

of

output

two

of

contents

at

specified

Don't

the

GOSUB stack. Used

made

operations.

expressions.

"0

'

results

game

controller.

of

specified

the

X, Y location

memory

try

to

in

other

position.

the

computer

only

loca-

POKE

than

to

the

If

Appendix

A-3

RESERVED

WORD:

ABBREVIATION:

BRIEF

OF

BASIC

SUMMARY

STATEMENT

PTRIG

PUT

RAD

READ

REM

RESTORE

RETURN

RND

RUN

SAVE

R.

PU.

REA.

or

RES.

RET.

RU.

•

lffilS'J

s.

Function

returns

controllers.

Causes to

Specifies

degrees

output

the

specified device.

that

when

Default is to

the

Read specified

Remarks. may reference starts

Allows

RETURN

ly

following

Function

but

Execute

dims

I/0

disk

This

be

printed

by

with

DATA

from

returns a random

never

the

arrays

statement

under

of a single

information

RAD.

items

statement

the

REM

to

subroutine

the

1.

program.

and

causes

filespec

status

of

the

byte

using

the

(See DEG.)

in

the

does

within

the

programmer.

are

not

executed.

be

read

more

to

one

in

which

Sets

string.

data

or

provided

of

is

trigger

data

in

button

from

radians

trigonometric

DATA

list

nothing,

program

Statements

than

once.

the

statement

GOSUB

number

normal

program

with

between 0 and

variables

to

SAVE.

on

the

computer

rather

functions.

and

assign

but

comments

list

for

on a line

immediate-

appeared.

to

be

recorded

game

than

to

future

that

0,

un-

on

1,

SETCOLOR

SGN

SIN

SOUND

SQR

STATUS

STEP

STICK

STRIG

STOP

A-4

Appendix

SE.

so.

ST.

STO.

Store

hue

register.

Function negative.

Function

(DEG

or

Controls a

tone

or

Function

status

Calls

Used

with

skipped

Function

Function if

pressed.

Causes off

execution

sounds.

and

luminance

returns

RAD).

register,

sound

note.

returns

the

routine

FOR/NEXT.

between

returns

each

position

returns 1 if

to stop,

color

+ 1

if

value

trigonometric

pitch,

square

for

root

specified

Determines

pair

of

stick

trigger

but

data

in a particular

is

positive, 0 if

sine

distortion,

of

the

device.

loop

variable

game

button

does

not

zero,

of

given

and

volume

specified

quality

values.

controller.

not

pressed,

close files

color

- 1

value

value.

to

or

turn

if

of

be

0

RESERVED

WORD:

ABBREVIATION:

BRIEF

OF

BASIC

SUMMARY

STATEMENT

STR$

THEN

TO

TRAP

USR

VAL

XIO

T.

X.

Function

value

returns a character

given. For example:

string.

Used

with statements trol

passes

Used loop

Takes and

directs

Function

with

range

control

are

to

FOR

expressions.

execution

returns

subroutine.

Function

returns

string.

General I/0

DOSIFMS

Manual)

IF:

If

executed.

as

in

of

program

results

the

statement

and

string

STR$(65)

expression

If

the

"FOR X = 1

in

to

case

a specified

of a machine-language

equivalent

used

with

in

graphics

equal

returns

is

true,

expression

TO

10".

of

an

line

number.

numeric

disk

operations

work

to

numeric

65

the

THEN

is false, con-

Separates

INPUT

error

value

(Fill).

as a

the

of

(see

a

App

endix

A-5

ERROR

CODE

NO.

ERROR

CODE

MESSAGE

APPENDIX

ERROR

MESSAGES

B

2

3

4

5

6

7

8

9

10

Memory

new

string

Value

pected

Too

(See

String

Out

DATA

Number

32767.

Input

numeric

Array

reference has array

Argument

sion.

Error: A value

to

Many

Variable

Length

of

Data

statement(s).

Statement

variable.

or

been

already

or

string.

insufficient

variable.

be

within

Variables: A maximum

Name

Error:

Error: READ

greater

String

is

out

of

Stack

to

expected

a specific

Limit.)

Attempted

than

32767:

Error:

DIM

Error:

the

range

DIMensi

Overflow:

store

range

statement

Attempted

of

oned,

the

statement

to

be a positive

is

not.

of

128

to

store

requires

Value

is

not a positive

to

DIM

size

is

the

dimensioned

or a reference

There

are

too

or

the

new

variable

integer

different

beyond

greater

the

more

INPUT a non-numeric

than

size, or

has

been

many

GOSUBs

is

negative, a value

variable

DIMensioned s

data

items

integer

32767

or

the

array/matrix

made

to

or

too

name

or

to

names

or

an

is

allowed.

tring

than

supplied

is

greater

value

an

array/martix

or

undimensioned

large

an

DIM a

ex-

length.

by

than

into

string

expres-

a

11

12

13

14

15

Floating

refer

to a number

Line

Not

number

No

Matching

FOR,

or

the

Too

handle.

GOSUB

and

the

Point

Overflow/Underflow

larger

Found:

.

nested

statement,

Long

or

FOR

corresponding

A GOSUB, GOTO,

FOR

FOR/NEXT

Error:

Line

than

1 x

Statement:

statements

not

at

FOR).

The

statement

Deleted:

FOR

or

96

10

A NEXT

GOSUB

or

do

has

Error:

smaller

THEN

was

not

match

is

too

or

RETURN

been

Attempted

than

referenced a non-existent

encountered

properly.

complex

deleted

to

1 x

statement

99

10-

without a previous

(Error

or

too

since

the

divide

•

long

was

last RUN.

by

zero

line

is

reported

for

BASIC

encountered

App

endix

or

at

to

B-1

ERROR

CODE

NO.

ERROR

CODE

MESSAGE

16

17

18

Note:

19

20

21

128

129

130

RETURN

Garbage

code POKE. any

Invalid

in

VAL

The

drives,

vided

LOAD

Device

LOAD

BREAK

IOCB

Nonexistent

Error:

may

indicate a hardware

Try

POKE

String

statement

following

printers,

with

program

Number

File

Abort:

1

already

A RETURN

Execution

typing

NEW

commands.

Character:

is

are

INPUT

or

the

auxiliary

Too

Larger

Error:

Attempted

User

open.

Device

was

of"garbage"

problem,

or

powering

String

not a numeric

/OUTPUT

other

Long:

accessory

hardware.

Insufficient

than 7 or

to LOAD a non-LOAD file.

hit

M,!;@M

key

specified.

encountered

(bad RAM bits)

but

may

down,

does

not

start

string.

errors

devices.

memory

Equal

to 0.

during

without a matching

was

attempted.

also

be

the

result

then

re-enter

the

with a valid

that

I/0

operation.

result Further

remains

during

information

to

GOSUB.

of

faulty

program

character,

the

use

complete

This

use

without

or

string

of

is

LOAD.

error

of

disk pro-

131

132

133

134

135

136

137

138

139

140

141

142

1

IOCB

refers

IOCB

Invalid

Device

Bad

IOCB

EOF:

using

Truncated

Device

Serial

Cursor

Serial

to

Input/Output

Write

IOCB

Read

End

Only.

Command:

or

File

Number:

Only

of

File

cassette files.)

Record:

Timeout.

NAK:

Garbage

bus

input

out

of

range

bus

data

Control

READ

The

command

not

Open:

Illegal

Error: WRITE

read

has

Attempt

Device

doesn't

at

framing

for

particular

frame

overrun.

Block.

command

to a

is

invalid

write-only

No OPEN specified

device

number.

command

been

reached.

to

read a record

(NOTE:

respond.

serial

port

or

bad

error.

mode.

The

device

number

for

to a

longer

disk

is

device

this

device.

the

device.

read-only

This

message

than

drive.

the

same

(Printer).

device.

may

256

characters.

as

the

IOCB

occur

number.

when

B-2

Appendix

ERROR

CODE

NO.

ERROR

CODE

MESSAGE

143

144

145

146

147

160

161

162

163

164

165

166

167

168

Serial

Read

Function

bus

Device

diskette.

after

data

done

write

not

Insufficient

Drive

Too

Disk

number

many

full

OPEN

(no

Unrecoverable

File

number

File

name

error.

POINT

File

Command

data

locked.

invalid

frame

error

(invalid "done"

compare

implemented

RAM

for

operating

error.

files

free

sectors).

system

mismatch:

length

error.

(special

checksum

error

in

(no

sector

data

I/0

Links

operation

error.

byte):

(disk

handler.

selected

buffer

error.

on

disk

code).

Attempt

handler)

graphics

available).

are

messed up.

to

or

bad

mode.

write

on a write-protected

screen

mode

handler.

169

170

171

Atari 400 Basic Reference Manual

Specifications and Main Features

Frequently Asked Questions

User Manual