Commodore vic-1540 User Manual

commodore

WiC-Ii

USER'S

MANUAL

SINGLE

DRIVE

FLOPPY

piSK

by

commodore

SINGLE

DRIVE

FLOPPY

DISK

USER'S

MANUAL

p

N154OOO18-OS

commodore

The

information

in

this

manual

has

been

reviewed

and

is

believed to

be

entirely

reliable.

No

responsibility,

however,

is

assumed

for

inaccuracies.

The

material

in

this

manual

is

for

information

purposes

only,

and

is

subject

to

change

without

notice.

©Commodore

Business

Machines,

Inc.,

September

1981

"All

rights

reserved."

Commodore

Business

Machines

3330

Scott

Boulevard

Santa

Clara,

California

95050

TABLE

OF

CONTENTS

Page

Chapter

1

Introduction

j

General

Information

j

Description

j

Front

Panel

4

Back

Panel

4

Interior

Configuration

4

The

Diskette

4

Specifications

4

Care

Of

The

VIC-1540

7

Care

Of

The

Diskettes

7

Unpacking

The

Disk

Drive

7

Chapter

2

Preparing

To

Use

Your

Disk

Drive

9

Connecting

The

Disk

Drive

To

The

Computer

9

Performing

The

Power-On

Test

10

Inserting

The

Diskette

!

1

Disk

Drive

Performance

Test

12

Chapter

3

Learning

How

To

Use

Your

Floppy

Disk

Drive

15

The

Block

Availability

Map

(BAM)

..-...-

jg

The

Disk

Operating

System

(DOS)

.

16

Disk

Maintenance

Commands

jg

NEW

17

Initialization

19

The

Directory

20

LOADS

20

Printing

The

Directory

•

• • ••21

VALIDATE

t

21

COPY

22

RENAME

23

SCRATCH

23

Chapter

4

BASIC

Commands

For

Data

Handling

25

BASIC

Commands

Ascociated

with

Floppy

Disk

Drives

25

SAVE

(Writing

a

Program

toaDiskette)

26

VERIFY

27

LOAD

(Reading

a

Program

fromaDiskette)

27

OPEN

28

CLOSE

29

Closing

The

Command

Channel

30

Closing

The

Data

Channel

30

PRINT

#

31

INPUT

#

32

GET

#

33

MovingaTape

Program

to

Disk

34

Chapter

5

Advanced

Disk

Programming

35

Commodore

Disk

Operating

System

(DOS)

35

Special

OPEN

and

CLOSE

Statements

for

Direct

Access

..

3$

Disk

Utility

Command

Set

36

BLOCK-READ

38

BLOCK-WRITE

39

BLOCK-EXECUTE

39

BUFFER-POINTER

39

BLOCK-ALLOCATE

40

BLOCK

FREE

40

MEMORY

41

MEMORY-WRITE

41

MEMORY-READ

41

MEMORY-EXECUTE

42

USER

42

Structure

of

Diskette

43

Chapter

6

Sequential

File

49

To

CreateaSequential

File

and

Accessing

49

Example

ofaSequential

File

Program

5q

Chapter

7

Random

File

53

Data

Flow

in

Random

File

..

53

Example

of

Using

Record

Number

55

Example

ofaRandom

File

Program

57

Chapter

8

Error

Messages—Pattern

Matching

File

Names

61

Requesting

Error

Messages

..

61

Summary

of

DOS

Error

Messages 61

Description

of

DOS

Error

Messages

62

Pattern

Matching

66

Appendix

69

List

of

Illustrations

Figure

Title

Page

1

Front

Panel

5

2

Back

Panel

5

3

Floppy

Disk

Hookup

jq

4

Position

For

Diskette

Insertion

• • •

11

5

1540

Format.

Expanded

View

ofASingle

Sector

47

6

Data

Flow

between

Computer,

Buffer

and

Disk

Drive

53

List

of

Tables

Table

Title

Page

1

Suggested

Reading

List

2

Specifications:

Model

1540

Single

Drive

Floppy

Disk

6

3

Standard

Jump

Table

43

4

Block

Distribution

by

Table

43

5

1540

BAM

Format

44

6

1540

Directory

Header

44

7

Directory

Format

45

8

Sequential

Format

46

9

Program

File

Format

46

10

Allocation

of

Record

Number

57

Chapter

1

INTRODUCTION

GENERAL

INFORMATION

With

the

purchaseofyour

Commodore

VIC-1540

Single

Drive

Floppy

Disk

you

have

greatly

enhanced

the

computing

power

of

your

Commodore

VIC

system.

To

get

the

most

outofyour

system

you

should

study

your

computer's

user

guide,

and

if

necessary

the

BASIC

manuals

listed

in

Table

1.

You

will

benefit

mostifyou

first

read

through

this

entire

manual,

taking

note of

those

features

that

relatetoyour

particular

floppyaswellasthose

which

are

commontoall

Commodore

Floppys.

The

information

presentedinthis

manualisextensive

and

may,insome

cases,

present

information

that

is

currently

beyond

your

particular

level

of

expertise.

However,

by

carefully

and

thoughtfully

studying

its

contents

you

will

gain

the

confidence

necessary

to

progressively

upgrade

your

programming

skills

and

expertise.

This

manual

presents

discussions,

descriptions, practices

and

procedures

relat

ingtothe use

and

operation

of

the

VIC-1540

Single

Floppy

Disk

Drive.

DESCRIPTION

The

VIC-1540

described

in

this

manual

is

an

intelligent

single

drive

diskette

storage

device.

Its

individual

primary

components

consists

of

read/write

controls,

drive

motor

electronics,

drive

mechanism,

read/write

head,

and

track

positioning

mechanism.

The

disk

drive

discussed

in

this

manual

uses

Serial

interface

same

as

The

VIC-1515

graphic

printer.

Because

the device

is

an

"intelligent"

peripheral,

its

operation

requires

no

space

in

the

computer's

memory.

This

means

you

have

just

as

much

computer

memory

available

to

you

as

when

youdonot have

the

disk

attached.

Table1.Suggested

Reading

List

Pet/CBM

Personal

Computer

Guide.

C.S.

Donahue

and

Jit.

Enger,

Osborne/McGraw-Hill,

630

Brancroft

Way,

Berkeley,CA94710

Hands-On

Basic

withaPet.

H.D.

Peckham,

McGraw-Hill

1979

Entering

BASIC.

J.

Sack

andJ.Meadows,

Science

Research

Associates,

1973

BASIC:AComputer

Programming

Language.

C.

?Qgeh,Holden-Day,

Inc.,

1973

BASIC

Programming.

J.

Kemeny

and

T.

Kurtz,

Peoples

Computer

Co.,

1010

Doyle

(P.O.

Box

3100),

Menlo

Park,

CA

94025,1967

BASIC

FOR

HOME

COMPUTERS.

Albrecht,

Finkle

and

Brown,

People

Computer

Co.,

1010

Doyle

(P.O.

Box

3100),

Menlo

Park,

CA

94025,1973

A

Guided

TourofComputer

Programming

in

BASIC.

T.

Dwyer,

Hough

ton

Mifflin

Co.,

1973

Programing

Time

Shared

ComputerinBASIC.

Eugene

H.

Barnet,

Wiley-Interscience,

L/C

72-175789

Programing

Time

Shared

ComputerinBASIC.

Eugene

H.

Barnett,

Wiley-Interscience,

L/C

72-175789

Programming

Language

#2.

Digital

Equipment

Corp.,

Maynard,MA01754

101

BASIC

Computer

Games.

Software

Distribution

Center,

Digital

Equipment

Corp.,

Maynard,

MA

01754

WhatdoTo

After

You

Hit

Return.

Peoples

Computer

Co.,

1010

Doyle

(P.O.Box

3100),

Menlo

Park,

CA

94025

Basic

BASIC.

JamesS.Coan,

Hay

den

Book

Co.,

Rochelle

Park,

NJ

WORKBOOKS

1-5.

T.I.S.,

P.OJBox

921,

Los

Alamos,NM87544

Programming

the

6502.

R.

Zaks,

Sybex,

1978

24

Tested,

Ready-to-Run

Game

ProgramsinBasic.

K.

Tracton,

Tab

Books,

1978

Some

Basic

Programs.

M.

Borchers

andR.Poole,

Osborne&Assoc.

Inc.,

1978

Basic

Programming

for

Business.

I.H.Forkner,

Prentice-Hall

1977

The

Channel

Data

Book.

B.

Lewis,

5960

Mandarin

Ave.,

Goleta,CA93017,1978

PET

and

the

IEEE

488

Bus

(GPIP).

Osborne/McGraw-HW,

630

Bancroft

Way,

Berkeley,

CA

94710

Personal

Computingonthe

VIC

20

Commodore

International,

Ltd

Norristown,

PA

19403,

1981

VIC-20

Programmer's

Reference

Guide

Commodore

Business

Machines

Inc.

3330

Scott

Blvc.

Santa

Clara,

CA95050,1981

Front

Panel

The

front

panelofthe

disk

drive

consistsofan

identification

panel

across

the

top;

slotinwhichtoinsertadiskette;

andadoortoclose

after

inserting

the

diskette.

When

the

door

is

closed,

the

diskette

is

clamped

onto

the

diskette

spindle

hub.

Alsoonthe

front

panel

are

two

LED

indicator

lights.

The

red

LED

on

the

slot

side

lights

when

driveisactive

and

flashes

wheneveradisk

error

occurs.

The

green

LED

on

the

lower

left

side

isapower

indicator

which

lights

when

powerisON.

Back

Panel

The

Back

of

the

disk

drive

contains

two

serial

interface

connectors.

Near

the

panel's

lower

edge

is

the

power

connector.

There

is

alsoa"slow

blow"

fuse.

Interior

Configuration

The

interior

of

your

floppy

contains

a

disk

drive.

All

the

logic

for

the

disk

drive

is

contained

within

the

unit.

The

mechanical

devices

are,

for

the

most

part,

located

beneath

the

disk

spindle.

The

Diskette

The

diskette

(also

known

asaminifloppy,

floppy

diskette,

minidiskette,

etc.)

is

similar

to the standard

flexible

disk.

There

are

several

reputable

manufacturers

of

the

5&-inch

diskettes.

You

should

make

sure

that

you

buy

diskettes

for

SOFT

SECTORED

FORMAT.

Your

Commodore

dealer

can

supply

your

needs.

Specifications

Table2presents

the

specifications

for

the

VIC-1540.

iVIC-1540!

\

DRIVE

INDICATER(RED

LED)

LIGHT:ACTIVE FLASH:

ERROR

POWER

INDICATER

(GREEN

LED)

LIGHT:POWER

ON

Figl. Front

Panel

POWER

SWITCH

SERIAL

BUS

FUSE/HOLDER

Fig

2.

Back

Panel

Table

2.

Specifications

VIC-1540

Single

Drive

Floppy

Disk

STORAGE

Total

capacity

Sequential

Relative

*

Directory

entries

Sectors

per

track

Bytes

per

sector

Tracks

Blocks

IC's:

6502

6522(2)

Buffer

2114(4)

PHYSICAL:

Dimensions

Height

Width

Depth

Electrical:

Power

requirements

Voltage

Frequency

Power

MEDIA:

Diskettes

174848

bytes

per

diskette

168656

bytes

per

diskette

167132

bytes

per

diskette

65535

records

per

file

144

per

diskette

17to21

256

35

683

(664

blocks

free)

microprocessor

I/O,

interval

timers

2KRAM

97

mm

200

mm

374

mm

100,120,220,

or

240

VAC

50or60

Herts

25

Watts

Standard

mini

5%",

single

sided,

single

density

*

Although

VIC-1540isdesigned

withacapability

to

handle

relative

files,

it

can

notbeused

with

the

current

versionofVIC-1001

personal

computer.

CAREOFTHEVIC-1540

The

disk

drive

shouldbeplacedona

flat

surface

freeofvibration.

It is

important

that

dust

particles

be

kept

ataminimum

sinceaparticle

buildup

will

interfere

with

optimum

operation.

If

you

should

experience

a

hardware

failure

contact

your

Commodore

dealer.

Any

attempt

to

correct

the

problem

yourself

could

resultinvoiding

the warranty.

CARE

OF

THE

DISKETTES

Handle

diskettes

with

care.

Follow

these

instructions

to

maintain

the

quality

of

the

diskette

and

to

protect

the

integrity

of

the

data:

1.

Return

the

diskette

to

its

storage

envelop

whenever

it is

removed

from

the

drive.

2.

Keep

the

diskettes

away

from

magnetic

fields.

Exposure

toamagnetic

field

can

distort

the

data.

3.

Never

leaveadisketteontop of

your

computerordisk

drive.

4.

Do

not

writeonthe

plastic

jacket

withalead

pencilorball-point

pen.

Use

a

felt

tip

penorfill

out

the

label

before

attaching

ittothe

jacket.

5.

Do

not

expose

diskettes

to

heat

or

sunlight.

6.

Do

not

touch

or

attempt

to

clean

the

diskette

surface.

Abrasions

will

cause

lossofstored

data.

7.

Before

applying

power

to

the

VIC-1540

open

the

drive

door

and

remove

the

diskette.

UNPACKING

THE

DISK

DRIVE

Before

unpacking

the

disk

drive,

inspect

the

shipping

carton

for

signs

of

ex

ternal

damage.Ifthe

cartonisdamaged,beespecially

careful

when

inspecting

its

contents. Carefully

remove

all

packing

material

and

the

contentsofthe

carton.DONOT

discard

any

packing

material

should

contain:

1.

VIC-1540

Single

Floppy

Disk

Drive

2.

UserMannual,

Number

1540018-02

3.

TEST/DEMO

diskette:

4.

WARRANTY

CARD

If

any

items

are

missing,

please

contact

your

Commodore

dealer

immediately.

NOTES

Chapter

2

PREPARING

TO

USE

YOUR

DISK

DRIVE

Before

starting

to

use

your

disk

drive,

make

sure

it

is

in

good

working

condition.

This

includes

properly

connecting

it

to

your

computer,

giving

itapowr-on

and

initial

checkout

test,

and

finally

the

performance

test

using

the

appropriate

TEST/DEMO

diskette.

CONNECTING

THE

DISK

DRIVE

TO

THE

COMPUTER

The

connector

cable

is

required

to

interface

the

floppy

to

the

computer.

This

cable

is

be

supplied

with

your

disk

drive.

NOTE:

The

disk

drive

should

be

the

first

peripheral

attached

to the

computer

if

other

devices

aretobe

"daisy-chained".

Follow

these

stepstoconnect

the

disk

drivetoyour

computer:

STEP

1:

Turn

power

OFF

to

the

computer

and

the

expansion

module,

STEP

2:

Place

the

disk

drive

inaconvenient

location

as

close

as

possible

to

the

computer.

DO

NOT

connect

the

disk

drive

to a

power

outlet

at

this

time.

STEP

3:

Connect

the

serial

cable

between

the

serial

interface

connector

on

the

computer

and

the

connectoronthe

disk

drive.

STEP

4:

Connect

the

disk

drive

power

cable

to

an

AC

outlet.

DO

NOT

turn

on

power

at this

time.

VIC-20

Personal

Computer

VIC-1540

Single

Drive

Floppy

Disk

VIC-1515

Graphic

Printer

Fig

3.

Floppy

Disk

Hookup

PERFORMING

THE

POWER-ON

TEST

You

are

now

ready

to

proceed

with

the

power-on

part

of

the

checkout:

STEP

1:

Open

the

disk

drive

door.

Ensure

that

no

diskette

is

present

in

the

drive.

STEP

2:

Turn

Power

ON

to

the

expansion

module

(have

the optional

cartridge

inserted

before

turning

power

on.)

STEP

3:

Turn

power

ON

to

the

COMPUTER

and

verify

that

is

working

properly.

STEP

4:

Apply

power

to

the

disk

drive.

All

two

indicator

lights

(LED)

on

the

front

panel

will

light.

After

about1second

the

red

drive

indicator

will

go

out

and

the

green

power

indicator

will

remain

on.

If

the

red

drive

indicator

keeps

on

flashing,

turn

the

power

OFF.

Wait

one

minute

and

try

again.

If

the

above

condition

continues,

contact

your

Commodore

dealer.

10

Note:

If

the

problem

persists,

try

disconnecting

the

other

devices

attached

to the

sesial

interface.

This

should

assure

thataproblem

another

device

does

not

affect

the

disk

drive.

WRITE

PROTECT

NOTCH

WHEN

COVERED,

DISKETTE

CONTENTS

CANNOT

BE

AL

TERED

Fig4.Position

for

Diskette

Insertion

INSERTING

THE

DISKETTE

CAUTION:

NEVER

APPLY

POWER

TO THE

DISK

DRIVEIFDISKETTE

IS

PRESENT

(LOCKED

AND

SEATED)

IN

THE

DRIVE.

STEP

1:

Ensure

that

the

power

to

the

disk

drive

is

OFF

and

DO

NOT

apply

power

until

you

complete

this

step.

Open

the

disk

drive

door

and

make

sure

that

no

diskette

is

present

in

the

drive.

STEP

2:

STEP

3:

STEP

4:

STEP

5:

If

the

preceeding

conditions

have

been

met,

you

may

apply

power

to

the

disk

drive.

Insert

the

diskette

into

the

slot

and

with

the

write

protect

tab

oriented to

the

left.

Once

the

diskette

is

in

the

slot,

gently

push

on

it

until

it

is

fully

seated.

Press

DOWN

firmly

on

the

spring-loaded

door

of

the

drive

until

you

hearadistinct

"click".

The

diskette

is

now

locked

and

seated

in

the

drive,

ready

for

processing

by

the

computer.

STEP

6:

To

remove

the

diskette,

insert

your

index

finger

under

the

lip

of

the

spring-loaded

door

and

gently

PULL.

This

will

release

the

door

and

permit

access

to

the

diskette.

The

diskette

is

now

free

to

be

removed

from

the

drive

11

DISK

DRIVE

PERFORMANCE

TEST

When

you

have

successfully

completed

the

Power-On

test,

proceed with

the

Performance

Test.

Don't

worryifyou

don't

fully

understand

exactly

what

is

happening

in

this

test.

At

this

point,

enter

the

commands

just

to

getafeel

for

what

you

can

do

with

your

disk.

If

UNEXPECTED

results

are

obtained

during

any

step

of

the

test,

stop

and

start

over

again.

The

most

likely

cause

of

a

problem

is

an

improperly

entered

command.

This

is

to

be

expected

until

you

become

familiar

with

your

disk

unit.

All

commands

are

entered

via

the

keyboard

and

must

be

followed

byacarriage

return:

press

the

RETURN

key

on

your

keyboard.

NOTE:

Commands

must

be

entered

exactly

as

shown.

DO

NOT

insert

any

spaces

unless

shown

in

the

example.

If

the

error

indicator

lights,

you

may

be

able

to

continue

the

example anyway.

Re-enter

your

last

command.

If

the

light

goes

out,

your

correction

was

successful

and

you

may

continue.

STEP1:

Insert

the

DEMO

diskette

into

the

drive

as

previously

instructed.

STEP

2:

Type:

OPEN

1,

8,15,

"10"

and

press

return.

This

pocedure

initializes

the

diskette

and

makes

it

ready

for

use.

STEP

3:

Type

LOAD

"PERFORMANCE

TEST",

8

The

screen

will

display:

SEARCHING

FOR

PERFORMA

NCE

TEST

LOADING

READY.

STEP

4:

Type:

RUN

and

press

RETURN,

the

following

will

display:

FERFQRMflNCE

TEST

INSERT

SCRflTCH

DISKETTE

IN

DRIVE

12

B:SK

NEW

CCMMRNB

WRIT

flBOUT

30

SECONDS

Do

not

use

diskettes

containing

any

valuable

information

since

the

Performance

Test

Program

will

re-format

it

and any

data

will

be

lost.

The

test

program

will

label

this

diskette

"Test

Disk".

This

diskette

is

ready

for

further

use

when

the

test

program

is

completed

and

the

performance

test

has

been

satisfied.

The

computer

will

first

format

the

diskette

in

the

drive.

At

the

end

of

the

operation

the

screen

displays:

9

OK

0

9

DRIVE

PflSS

MECflNICRL

TEST

The

computer

conducts

the

remainder

of

the

Performance

Test

and

displays:

OPEN

URITE

FILE

0

OK

0 0

WRITING

DRTfl

0

OK

6 0

CLOSE

WRITE

DflTfl

9

OK

0 0

0^

RERD

g

0K

0

e

RERDING

DflTR0ok

^ @

SCRRTCH

FILE

CRflTCHED

10

13

WRITE TRRCK

35

8

OK

0

9

WRITE

T'?flCK

1

0

OK

0

9

REflD

TRRCK

35

8

OK

0 0

REflD

TRflCK

1

0

OK

0

HBS

PfiSSEB

PERFORMfiRCE

TEST!

PULL

DISKETTE

FROM

DRIVE

BEFORE

TURNING

POWER

OFF.

STEPS:

Remove

the

diskettes

and

return

them

to

their

protective

jackets.

The

floppy

has

passed

the

Performance

Test.

STEP

6:

If

any

problems

have

been

encountered

during

this

phase

of

the

test,

return

to

Step1and

repeat

the

entire

procedure.

If

problems

persist

and

you

do

not

reachasatisfactory

conclusion

to

the

Performance

Test,

contact

your

Commodore

dealer.

14

Chapter

3

LEARNING

HOW

TO

USE

YOUR

FLOPPY

DISK

DRIVE

Your

Floppy

Disk

Drive

adds

and

enhances

your

computing

power

with

added

storage

and

file

handling

capability

andiscontrolled

directly

with:

•

BASIC

commands

entered

via

the

keyboard,

•

BASIC

statements

within

programs,

and

•

special

disk

commands.

In

this

chapter

you

will

learn

howtoapply

those

commands

and

statements.

This

chapter

is

organized

in

suchaway

that

the

functions

and

format

of

disk

commands

are

described

inamanner

which

permits

the

user

to

perform

disk-

Before

using

your

floppy

disk

make

sure

you

know

how

to:

1.

operate

your

Commandore

VIC

Computer,

2.doelementary

programming

in

BASIC,

and

3.

open

and

close

files.

This

chapter

will

first

acquaint

the

user

with

those

fundamental

disk

commands

that

perform

disk

maintenance

and

file

manipulation

and

will

then

progressively

advance

towardanunderstanding

of

those

BASIC

commands

used

for

data

handling.

Approachedinthis

manner,

the

user

will

then have

developed

the

necessary

confidence

and

programming

skills

to

proceed

to

advanced

disk

programming

techniques.

Practice

the

disk

commands,

read

the

examples,

and

follow

the

step-by-step

illustrations

of

their

usage.

The

understanding

of

the

more

advanced

disk

programming

techniques

will

dependtoa

large

degree

upon

how

well

the

fundamentals

have

been

mastered.

To

facilitate

your

understanding

and

masteryofCommodore

BASIC,

two

computer

terms

are

stressed

in

this

Chapter:

Block

Availability

Map

(BAM)

and

Disk

Operating

System

(DOS).

Although

these

are

conventional

terms,

they

will

be

riefly

discussed

as

they

relate

to

Commodore

Floppy

Disk

Usage.

15

THE

BLOCK

AVAILABILITY

MAP

(BAM)

The

BAM

isadisk

memory

representation

of

available

and

allocated

space

on

a

disk.

When

the

system

stores

informationona

disk,

the

BAM

willbeauto

matically

referenced

by

the

DOS

to

determine

what

space

is

available

and

how

many

blocks

can

be

allocated.

Iff

sufficient

space

is

available

to

storeagiven

file,

it

will

be

stored

on

the

disk

and

the

BAM

updated

to

account

for

the

space

allocated.

However,

if

the

DOS

detects

thatafile

will

occupy

more

space

than

available,

an

error

message

will

be

generated.

Formatting

a

disk

creates

the

BAM

which

is

then

loaded

into

DOS

memory

upon

initialization.

The

BAM

is

stored

on

diskette

in

varying

locations

depending

upon

the

drive

used:

BAM

Location

and

Memory

Required

Track

18,

Sector0128

bytes

As

changes

occur

to

the

BAM

in

DOS

memory,

the

BAM

on

disk

will

be

updated

to

reflect

these

changes.

Updates

to

the

BAM

occur

whenaprogram

is

saved

or

a

CLOSE

is

performed

onanew

SEQuential

data

file.

THE

DISK

OPERATING

SYSTEM

(DOS)

The

DOS

is

responsible

for

managing

information

exchange

between

the

disk

controller

and

the

computer.

The

DOS

performs

many

functions

which

are

transparent

to

the

user

but

which

are

vital

to

the

operation

of

the

system.

For

example,

the

DOS

monitors

the

input/output

(I/O)

of

the

disk

so

that

channels

are

properly

assigned

and

that

no

lengthy

waits

for

an

open

channel

occur.

In

addition

to

monitoring

of

disk

I/O,

the

DOS

also

uses

the

channel

structure

to

search

the

directory

and

to

delete

and

copy

files.

DISK

MAINTENANCE

COMMANDS

The

following

disk

commands

permit

the

user

to

perform

file

manipulation

and

disk

maintenance.

16

Diskette

Level

<

File

Level

<

BASIC

COMMAND

NEW

INITIALIZE

LOAD

"$"

VALIDATE

COPY

RENAME

SCRATCH

FUNCTION

Formatsadisk

Prepare

diskette

for

use

Read

disk

directory

Reconstruct

Block

Availability

Map

(BAM)

Copies

files

(optional

con

catenation)

Renamesafile

Erasesafile

NOTE:

Diskette

commands

can

be

transmitted

to

the

disk

by

PRINT#

com

mands.

The

examples

in this

chapter

assume

thatafile

has

been

opened

with

the

OPEN

15,

8,

15

command.

If

the

error

message?FILE

OPEN

ERROR

ap

pears

upon

typing

the

OPEN

command,

it

means

that

the

logical

file

was

opened

but

had

not

been

properly

closed.

When

this

error

appears

such

logical

file

mustbeproperly

closedbytyping

CLOSE

15.

NEW

Each

timeadiskette

is

placed

in

one

of

the

drives,

both

the

diskette

and

the

drive

must

be

prepared

for

use.Apreviously

unused

diskette

must

first

be

formatted

in

the

soft-sector

format

recognized

by

your

particular

disk

drive.

This

may

be

accomplished

by

use

of

the

NEW

disk

command.

To

use

the

NEW

command,

to

format

the

diskette

and

initialize

the

disk

drive,

enter

the

command:

PRINT#15,

"commandstring"

where

15

is

the

logical

file

number

ofafile

which

has

been

opened

to

the

disk

command

channel

(primary

address

8,

secondary

address

15).

The

format

of

NEW

is:

17

"NEWdr:fn,xx"

or

•

"Ndrfnjcx"

Where

d=the

drive

number0(0

may

be

omitted)

fn=the

file

name

you

wishtoassigntothe

disk.Itmaybeup

to

16

characters

long.

xx=a

unique

two-character,

alphanumeric

identifier

supplied

by

the

user.

The

NEW

command

(with

ID

specified)

is

used

on

an

unformatted

diskette

or

one

which

the

user

wishestoreformat.

NEW

creates

the

block

headers,

writing

the

sync

characters,

disk

ID,

and

track

and

sector

numbers

at

the

beginning

of

each

block.

The

directory

header

and

the

BAM

are

created

and

the

diskette

is

made

readytoaccept

data.

The

command

maybeusedonan

already

formatted

diskette

(with

no

ID

specified)

to

clear

the

disk

directory

and

reinitialize

the

BAM,

deallocating

all

blocks

on

the

diskette.

The

time

involved

in

reformatting

withoutanIDismuch

less

than

formatting

withanID.

Example1:OPEN

15,8,15

PRINT#15,

"NO:TESTDISK,

88"

These

commands

will

open

the

command

and

error

channeltothe

disk

drive

and

format

a diskinthe

drive,

givingita

disk

identifer

of

88.

The

following

simplified

form

maybeused

for

this

purpose:

Example

2:

OPEN

15,

8,15,

"NO:TESTDISK,

88"

Here'sanexampleofreformatting

a diskette

using

the

NEW

command

and

no

disk

ID.

Example

3:

OPEN

1,8,15,

"NO

:NEWNAME"

The

diskette

will

be

assigned

the

name

"NEWNAME"

and

the

directory

and

BAM

will

be

cleared.

This

procedure

will

work

only

if

the

diskette

has

been

formatted.

The

NEW

disk

command

SHOULD

NOT

be

confused

with

the

NEW

command

18

in

BASIC.

The

latter

will

delete

the

program

currently

in

memory

and

clear

all

variables

before

enteringanew

program.

INITIALIZATION

Wheneveradiskette

is

inserted

into

the

drive,

for

any

reason,

it

MUST

be

initialized

to

ensure

that

the

information

on

the

BAM

(in

the

disk

memory)

is

the

proper

information

for

the

diskette

currently

in

the

drive.

Failure

to

proper

ly

initialize

a

diskette

each time

it

is

inserted

or

reinserted

into

the

drive

will

result

inaDISK

ID

MISMATCH

ERROR

and/or

loss

of

data.

The

VIC-1540

utilizes

a

DOS

2.6

software

routine

each

time

the

disk

is

ad-

dresed

to

determine

if

initialization

is

required.

Ifadifferent

ID

is

detected, the

VIC-1540

will

automatically

initialize

the

new

disk.

Operator

initialization

is

not

required

if

unique

IDs

are

assigned

each

diskette.

The

format

of

INITIALIZE

command

is:

PRINT#15,

"INITIALIZEdr"

Where:

dr=drive

number0(0

may

be

ommitted).

Note:

You

may

abbreviate

INITIALIZEtoI.

Example1:OPEN

15,

8,15

PRINT#15,"I0"

Example2:OPEN

15,

8,15,"I"

(You

may

omit

the

closing

double

quotation)

NOTE:

FILE

OPEN

ERROR

could

occurifa

previously

opened

file

was

ad

dressed

withasecond

OPEN

command.

When

this

error

appears

such

logical

file

must

be

properly

closed

by

typing

CLOSE

lfn.

The

disketteinthe

driveisnow

initialized.

Do

not

confuse

formatting

and

initialization.

Remember

that

formatting

is

usuallyaone-time

operation

and

that

re-formatting

a

disk

will

destroy

previously

stored

data.

Since

the

VIC-1540

initialization

function

depends

uponachange

of

ID

to

detectachange of

diskette,

inserting

a

diskette

with

an

ID

identical

to

one

previously

used

may

lead toaloss

of

data.

This

happens

because

the

computer

will

reference

the

BAM

left

over

from

the

Since

the

IDs

are

19

identical

the

DOS

assumes

there

have

beennochangeofdiskette.

A

SAVE

command

may

now

cause

new

datatobe

written

over

good

data

already

present

on

the

disk

because

the

DOS

will

use the

old

map

of

available

storage

area,

instead

of

the

current

one.

The

results

are

unpredicable,

and

the

diskette

may

become

totally

useless.

For

this

reason,

unique

disk

IDs

must

be

used

when

ever

possible

for

each

diskette.

THE

directory

display

includes

the following

information:

Disk

name

Disk

ID

DOS

version

number

File

name

File

type

Numberofblocks

used

Number

of

available

(free)

blocks

To

list

the

directory,

at

first

type

LOAD

"$0",

8.

(LOAD

"$",

8)

LOADS

This

procedure

will

destroy

any

program

currently

in

computer

memory

when

the

directory

is

LOADed.

STEP

1:

Placeaformatted

disk

in

the

drive.

STEP

2:

Type:

LOAD'T',8then

press

RETURN.

The

screen

displays:

LOAD"$",

8

SEARCHING

FOR

$

LOADING

READY'

STEP

3:

Type:

LIST

The

directory

for

the

drive

willbedisplayed.

20

Printing

The

Directory

Quite

often,itbecomes

convenient

to

affixadiskette

directory

listing

directly

on

the

protective

jacket.

This

permits

the

user

to

scan

the

printed

directory

listing

without

having

to

insert

the

diskette

into

the

drive

to

obtain

this

in

formation.

Should

you

desiretoprint

the

directory,

place

the

disketteinthe

drive

and

enter

the

following

commands:

LOAD

"$",

8

Loads

the

directory.

OPEN

4,

4:CMD4

Opens

device4(printer)

and

changes

the

primary

output

deviceto4.

LIST

Prints

the

directory.

PRINT#4:CLOSE4

Returns

output

to

the screen

and

closes

the

file.

VALIDATE

The

VALIDATE

command

traces

through each block

of

data

contained

in

all

files

on

the

diskette.

If

this

trace

is

successful,

a

new

BAM

is

generated

in

the

disk

memory

and

written to the

diskette.

Any

blocks

which

have

been

allocated

but

are

not

associated

withafile

name,

as

in

the

case

of

direct

access

files

will

be

freed

for

use.

In

addition

to

reconstructing

the

BAM,

VALIDATE

deletes

files

from

the

directory

that

were

never

properly

closed.

IfaREAD

error

is

encountered

duringaVALIDATE,

the

operation

aborts

and

leaves

the

diskette

in

its

pre

vious

state.

IfaVALIDATE

error

does

occue,

you

must

re-initialize

before

proceeding.

The

formatofVALIDATE

is:

PRINT#15,

"VALIDATEdr"

Where:

dr=drive

number0(0

may

be

ommited)

NOTE:

You

may

abbreviate

VALIDATE

to

V.

Example:

OPEN

1,8,15

PRINT#l,"V0"

21

or

OPEN1,8,15

"V"

COPY

The

COPY

command

allows

you

to

create

multiple

copies

(under

different

names)offilesonthe

same

diskette.

This

command

can

alsobeusedtocon

catenate

data

files.Upto

four

source

files

canbeconcatenated

into

the

destina

tion

file.

The

COPY

command

may

be

abbreviated

withaC.

COPY

disk

command

canbeformatted

two

ways

depending

upon

application:

To

copyasingle

file:

PRINT#1

fn,

"COPYddr:dfn=sfn"

or

PRINT#lfn,

"Cddr:dfn=sdr:sfn"

To

concatenate

and

copy:

PRINT#lfn,

"COPYddr:dfn=sfn,

sdnsfn

...

or

PRINT#lfn,

"Cddr:

dfn=sdr;sfn,

sdnsfn

Where:

ddr=is

the

destination

drive0(0

may

be

ommitted)

dfn=is

the

destination

file

name.

This

name

must

beanew

name.

sdr=is

the

source

drive0(0

may

be

omitted)

sfn=is

the

source

file

name.

Example

1:

PRINT#1,

"CO:ACCT1=0:ACCT"

A

file

named

ACCT,

is

copied

underanew

name

ACCT1

Example

2:

PRINT#1,"CO:JDATA=O:

ACCT1,

0:

ADATA,

O:BDATA"

Files

are

concatenated

intoafile.

Note

that

file

names

shouldbeshort,

as

the

maximum

lengthofa disk

command

stringis40

characters.

NOTE:

The

COPY

command

is

normally

used

in

the

Dual

Drive

Floppy

disk

to

copy

files

from

one

diskettetoanother.

But

this

function

can

not be

used

in

the

VIC-1540

which

isaSingle

Drive

Floppy

Disk.

22

RENAME

The

RENAME

command

renamesanexisting

file.Afile

can not

already

exist

with

the

file

name

specified

in

the

commandorthe

FILE

EXISTS

error

message

willbegenerated.

The

formatofRENAME

is:

PRINT#lfn,

"RENAMEdr:nfn=ofn"

Where:

dr=the

drive

number0(0

may

be

ommitted)

nfn=the

new

name

of

the

file.

ofn=the

old

nameofthe

file.

lfn=a

logical

file

number.

You

assign

this

number

arbitrarily

and

it

maybeany

whole

number

between1and

255.

NOTE:

The

letterRisalegal

abbreviation

for

RENAME.

NOTE:

Close

any

open

files

before

using

the

RENAME

command

since

the

disk

will

not

execute

this

command

on

any

active

files.

SCRATCH

The

SCRATCH

command

erases

unwanted

files

from

the

specified

diskette

and

its

directory.

You

can

eraseonfile,

several

files,orall

the

filesona

diskette.

The

formatofSCRATCH

IS:

PRINT*

lfn,

"sdr:fn,

dr:fn

. ..:dr:fn"

Where:

dr

is

the

drive

number

0.

(0

may

be

omitted)

fn

is

the

name

of

the

file

to

be

erased.

To

erase

one

file

enter,

the

entire

nameofthe

file:

Example:

PRINT#1,

"SO:ACCT"

To

erase

several

files

with

unrelated

names,

enter

the

entire

name

of each

file

to

be

deleted:

23

Example:

PRINT#1,

"SO:ACCT,

CUSTOMER,

INV"

To

erase

several

files

at

one

time

when

names

have

something

in

common,

refer

to the

rulesinclapter8concerning,

pattern

matching.

You

may

erase

all

files

onadiskette

using

pattern

matching

as

in

the

following

example:

Example:

PRINT#1,

"SO:*"

NOTE

24

Chapter

4

BASIC

COMMANDS

FOR

DATA

HANDLING

BASIC

COMMANDS

ASSOCIATED

WITH

FLOPPY

DISK

DRIVES

The

BASIC

commands

described

in

this

chapter,

allow

the

user to

communicate

with

and

transfer

datatoand

from

the

disk

drive.

These

commands

are

available

for

ALL

versions

of

Commodore

BASIC:

OPENlfn,

8,

sa,

"dr:fn,

ft,

mode"

VERIFY

"dr.fn",

8

CLOSElfn

PRINT#lfn

LOAD

"dr:fn"

8

GET#lfn

SAVE

"dr:fn",

8

INPUT#lfn

Where:

lfn=logical

file

number

(any

number

between1and

255)

fh=file

name

suppliedbyuser

dr=disk

drive

number0:

(0

may

be

omitted)

8=device

number

(8

for

disk,2for

second

cassette,

4

for

printer)

sa=secondary

address

ft=the

file

type.

It

may

be

SEQ

(for

sequential),

USR

(for

user),

or

PRG

(for

program)

mode=either

READ(R)

or

WRITE(W).

All

upper-case

characters

shown

in

format

are

essential

for

the

proper

execution

ofacommand

and

must

be

typed

by

use.

These

commands

are

entered

via

the

keyboard

using

unshifted

characters only.

NOTE:

The

device

numberofthe

disk

driveissetat8atthe

factory

prior

to

shipment.

If

you

wish

to

change

the

device

number

to

use

multiple

number

of

VIC-1540

etc.

Please

consult

your

Commodore

dealer

(the

device

number

may

be

any

number

from8to

11)

25

SAVE

(Writing

a

Program

toaDiskette)

Ifaprogramisin

computer

memory,itcanbemovedtoa

diskette

for

storage.

Thisisaccomplished

with

the

SAVE

commands.

Any

data

transferred

with

the

SAVE

command

are

automaticaly

designated

by

the

DOS

asaprogram

(PRG)

file.

Command

transfers

PRG

files

from

the

computer's

memory

to

the

specified

diskette.

You

must

specify

the

drive

number,

the

program name, and

the

device

number.

The

device

number

will

default

to

device1which

is

the

tape

unit

if

it

is

not

specified.

The

format of

SAVE

is:

SAVE"dr:fn",

dn

Where:

dr=is

the

drive

number0(0:

may

be

omitted)

fn=is

any

file

name

of

16

characters

or

less

you

wish

to

assign

to

the

file

to

be

transferred

to

the

diskette.

Blanks

are

counted

as

characters.

dn=is

the

device

number

anditmustbe8.

This

following

example

illustrates

creating

a

one

line

program,

SAVEing

it

on

the

diskette

in

the

drive

under

the

name

TESTPROG.

Example:

10?"THIS

ISATEST"

SAVE"0:TESTROG",

8

Another

formatofSAVE

is

SAVE"@dr:fn",dn

Where

@=means

to

replace

the

contents

of

an

existing

diskette

file.

fn=is

the

nameofthe

diskette

file

whose

contents

istobe

replaced.

Example:

SAVE

"@0:

TESPROG",

8

In

this

caseaprogram

named

TESTPROG

will

be

replaced,

but

if

the

specified

program

does

not

exist,

then

normal

SAVE

procedures

are

executed.

NOTE:

In case@is

used

in

the

SAVE

command,

avoid

its

repeated

use.

If

@

must

be

repeatedly

used,

execute

the

VALIDATE

command

before

the

SAVE

command.

26

VERIFY

The

VERIFY

command

performsabyte-by-byte

comparison

of

the

file

just

writtentothe

diskette

against

the

fileinthe

computer's

memory.

The

format

of

the

VERIFY

command

is:

VERIFY

"dr:fn",dn

Where:

dr=the

drive

number0(0:

may

be

omitted)

fn=the

same

file

nameasusedinthe

immediately

proceding

SAVE

command.

dn=the

device

number,inthis

case

8.

Another

formatofVERIFY

is:

VERIFY

"*",dn

Where:*causes

the

program

just

savedtobe

verified.

You

should

give

the

VERIFY

command

everytime

you

use

the

SAVE

command

to

placeafile

onadiskette.

If

you

do

this,

you

will

always

know

whether

or

not

the

file

was

copied

correctly.

LOAD

(Reading

a

Program

fromaDiskette)

A

program

stored

on

diskette

may

be

loaded

into

memory

using

the

LOAD

command.

The

LOAD

command

transfers

PRG

files

from

the

specified

diskette

to

the

computer's

memory.

You

must

specify

the

drive

number,

the

program

name,

and

the

device

number.

The

device

number

will

default

to

unit1which

is

the

cassette

unit.

The

formatofLOAD

is:

LOAD"dr:fn",

dn

Where:

dr=is

the

drive

number

0.

(0:

may

be

omitted)

fn=is

the

file

name

previously

specified

in

the

SAVE

command

and/or

stored

in

the

disk

directory.

27

dn=is

the

device

number

and

it

must

be

8.

The

following

example

illustrates

howaprogramisloaded

from

the

diskette

into

the

computer

memory,

then

executed.

To

do

this

example,

first

type

NEW

and

depress

RETURN

keytoclear

your

computer's

memorysothat

you

can

see

that

it

really

works.

Don't

confuse

the

NEW

command

in

BASIC

with

the

NEW

disk

command

usedtoformat

your

disk.

Example1:LOAD"0:TESTPROG",

8

READY.

RUN

THISISA

TEST

A

successful

LOAD

closes

all

open

files.

Therefore

you

must

giveanew

OPEN

command

in

order

to

continue

communicating

with

the

disk

drive

command

and

error

channel.

OPEN

This

command

sets

upacorrespondence

betweenalogical

file

number

and

a

file

which

exists

on

disk.

It

also

reserves

the

buffer

space

within

the

disk

unit

for

operations

on

the

file

being

opened.

The

format

of

the

complete

OPEN

command

is:

OPENlfn,

dn,

sa,

"dr:fn,

ft,

mode"

Where:1fn=the

logical

file

number

dn=the

device

number,inthis

case

8.

sa=the

secondary

address.

It

maybeany

number

from2to14and

maybeused

either

for

inputoroutputasspecified

in

mode.

See

note

below

dr=the

drive

number

0.

(0:

may

be

omitted)

fn=the

name

of

the

file.

ft=the

file

type.

It

may

be

SEQ

(for

sequential),

USR

(for

user),

or

PRG

(for

program).

mode

describes

how

the

channel

is

to

be

used.

It

may

be

either

READ

(R)

or

WRITE

(W).

28

NOTE:

Secondary

address15is

the

command

and

error

channel

and

has

special

uses

which

are

discussedinsubsequent

chapters.

Secondary

addressed

0

and

1

are

reservedbythe

operating

systems

(BASIC

and

DOS)

for

LOADing

and

SAVEing

programs.

Examples:

OPEN2,8, 2,

"O:FILE1,

SEQ,

WRITE"

OPEN

3,8,9,

"O:TESTDATA,

PRG,

WRITE"

OPEN8,8, 8,

,,0:NUM,USR,

READ"

The

contentsofan

existing

file

maybereplacedbypreceding

the

drive

number

with

an

at

sign

(@)

in

the

OPEN

command.

OPEN3,8,5,"@0:JDATA,

USR,

WRITE"

If

the

spefified

file

does

not

exist,

then

normal

OPENing

procedures

are

exe

cuted.

You

can

also

assign

some

of

the

OPEN

parameters

toavariable

name

as

il

lustrated

in

these

examples:

Example

1:

FL$="0:FILEA,

SEQ,

READ"

OPEN

1,8,14,

FL$

Example2:FL$="0:FILEA"

OPEN1,8,14,

FL$+",

SEQ,

WRITE"

The

preceding

methods

are

convenient

when

it

is

necessary

to

open

several

channelstothe

same

file

name.

CLOSE

The

CLOSE

command

closesafile

opened

by

the

OPEN

command.

Its

format

is:

CLOSE

lfn

Where:1fn=the

logical

file

number

ofafile

opened

by

the

OPEN

command.

Always

closeafile

after

working

with

it.

You

are

not

allowed

to

have

more

than

ten

open

files

in

the

computer

and

five

in

the

disk

drive,

so

it

is

prudent

to

make

a

habit

of

closing

files

as

soon

as

possible.

This

way

you

will

always

have

the

29

maximum

numberoffiles

available

for

use.

CLOSING

THE

COMMAND

CHANNEL

Closing

the

command

channel

closes

all

channels

associated

with

the

disk

drive.

No

other

partofthe

logical

file

environment

is

affected.

That

is,

the

computer

does

not

recognize

that

the

files

have

been

closed.

The

following

example

illustrates

a

situation

in

which

several

channels

are

closed

downbya

single

CLOSE

command.

Example:

The

command

channelisopened.

OPEN3,

8,

2,

"0:FILE1,SEQ,

WRITE"

Data

Channels

are

opened

for

OPEN4,

8, 5,

"O:FILE2,

SEQ,WRITE"

writing.

PRINT#3,

"IMPORTANT

DATA"

PRINT#4,

"MORE

DATA"

OPEN3,

4

A

channel

is

opened

to

the

printer

by

mistake.

?FILE

OPEN

ERROR?

An

error

messageisdisplayed

on

READY.

the

screen.

a

Since

there

was

an

error,

all

logical

files

in

the

computer

are

closed,

but

the

channelsinthe

disk

drive

are

still

open.Toclose

the

disk

channels,

type:

OPEN1,8,15

CLOSE1

Now

all

data

channelsinthe

disk

drive

are

properly

closed.

CLOSING

THE

DATA

CHANNEL

The

CLOSE

command

closesafile

and

the

data

or

command

channel

associated

with

it.

Whenever

you

closeafile

opened

with

a write

channel,

the

closing

of

that

file

writes

the

final

block

of

data

to

the

disk

and

updates

the

disk

directory.

When

you

closeafile

opened

witharead

channel,

that

channel

is

simply

closed

down.

NOTE:

Whenadrive

is

initialized

with

INITIALIZE,

NEW,

or

VALIDATE,

all

30

channels

associated

with

that

drive

are

deleted.

These

commands

should

not

be

executed

when

there

are

any

files

open

since

the

files

will

be

disrupted.

PRINT*

The

PRINT#command

transmits

a

disk

command

string

to

the

drive.

The

formatofPRINT#

is:

PRINT#lfn,

"commandstring"

Where:

lfn

=a

file

previously

opened

using

secondary

address

15

"commandstring"=disk

handling

or

disk

file

handling

commands.

These

disk

commands

are

discussedindetailinChapter3of

this

manual.

PRINT#

may

also

be

used

to

transmit

data

toapreviously-opened

sequential

or

user

file.

In

CBM

BASIC

V2

the

logical

file

number1to

127

send

carriage

return

alone

and

the

logical

file

number

128

to

255

send

CRLF.Asemicolon

(;)must

be

used

asaterminator

for

each

PRINT#

statement

when

using

the

logical

file

number

128to255toavoid

sending

extraneous

line

feedstothe

diskette.

It

is

important

to

be aware of

this

face

because

the

carriage

return

alone

is

seen

asaterminatory

by

the

DOS.

The

line

feedisthen

storedinthe

fileasthe

first

character

in

the

To

avoid

this,

use

the

following

format:

Example:

PRINT#128,

"JONESABC";

CHR$(13);

The

CHR$(13)

is

the

carriage

return

necessary

for

the

proper

terminating

of

the

record

on

the

disk.

When

that

record

is

input,

the

result

will

be

JONESABC

whichisthe

desired

result.

The

following

format

may

that

be

used:

PRINT#lfn,A$

It

will

produce

the

desired

value

of

A$

for

the

record,

and

will

not

interfere

with

the

Several

variables

maybewrittentothe

diskatthe

same

time.

31

The

format:

PRINT#lfn,A$,B$,C$

will

result

inasingle

variable

(A$+B$+C$)

being

retrieved

by

the

input

command.

The

format:

PRINT#lfn,A$CHR$(13)B$CHR$(13)C$

will

result

in

the

variables

A$,

B$,

and

C$

being

separated

by

carriage returns,

and

they

may

thenbeinputasseparate

variables.

INPUT*

The

INPUT#

command

is

used

to

transfer

information

fromaperipheral

device

such

as

the

disk

drive

into

computer

memory.

INPUT#is

valied

only

when

used

inaprogram

and

only

when

referencing

a

logical

file

that

has

been

OPENed

for

input.

The

format

for

INPUT*is:

INPUT#1

fn,

A$

or

INPUT#1

fn,

A

Where:

1

fn=file

previously

opened

using

secondary

address

15

A$=astring

variable

which

will

contain

the

data

transferred.

A=a

numeric

variable

which

will

contain

the

data

transferred.

INPUT

may

also

be

used

to

transfer

several

strings

of

data

at

one

time:

INPUT#lfn,A$,B$,C$

Where:

A$,

B$,

C$

will

contain

the

data

transferred

from

the

disk.

In

this

format,

the

data

strings

must

have

been

separated

by

carriage

returns

(

CHR$(13)

)

at

the

time

they

were

written

to

the

disk

in

order

to

be

retrived

separately.

No

single

string

may

contain

more

than

88

characters

if

it is

to

be

INPUT.

32

Example

1:

.

20

INPUT#2,

A

Input

the

item

which

must

be

in

numeric

form

and

assign

the

valuetoaviable

A.

Example

2:

10INPUT#8,A$

Input

the

item

asastring

and

assign

it

to

variable

A$.

Example

3:

60

INPUT#7,

B,

C$

Input

the

data

items

and

assign

the

first

to

numeric

variable

B

and

the

second

to

string

variable

C$.

For

strings

longer

than

88

characters,

the

GET#

commmand

must

be

used.

GET#

The

GET#

command

is

used

to

transfer

individual

bytes

of

information

from

an

serial

device

such

as

the

disk

drive

into

computer

memory.

GET#

is

valid

only

when

usedina

program

and

only

when

referencing

a

file

that

has

been

OPENed.

The

format of

GET#is:

GET#lfn,A$

Where:

lfn=a

file

previously

opened

using

secondary

address

15

A$=a

string

variable

which

will

contain

the data

transferred.

GET#

may

also

be

used

to

transfer

several

bytes

of

information,

which

is

useful

for

retrieving

strings

which

has

been

written

to

the

disk

inaformat

which

is

unacceptable

for

the

INPUT

command

(strings

longer

than

88

characters).

33

Forexampel:

10AA$=""

20

FOR

1=1TO254

30GET#lfn,A$

40

AA$=AA$+A$

50

segment

which

would

result

inastring

of

length

254

being

trans

ferred

from

the

disk

(logical

file

number

lfn) to

the

computer

memory

and

stored

in

the

variable

AA$.

MOVINGATAPE

PROGRAM

TO

DISK

This

example

illustrates

a

session

with

the

computer,atape

cassette

andadisk

drive.

The

purpose

is

to

copyacassette

program

toadiskette.

The

program

is

than

read

from

the

diskettetothe

computer's

memory

and

printed.Itis

assumed

that

the

BASIC

program

was

previously

stored

on

the

cassette.

Example:

LOAD"DEMO"

PRESS

PLAY

ON

TAPE

OK

SEARCHING

FOR

DEMO

FOUND

DEMO

LOADING

READY.

SAVE"DEMO",8

VERIFY

"DEMO",

8

READY.

NEW

LOAD

"DEMO",

8

SEARCHING

FOR

DEMO

LOADING

READY.

RUN

Load

the

file

from

the

cassette

tape

to

the

computer's

memory.

Createaprogram

file

containing

the

programondiskette.

Erase

everything

from

memory.

(The

NEW

command

in

BASIC

will

clear

memory;

the

NEW

disk

command

will

formatadisk.)

Load

the

program

back

into

the

com-

putegr's

memory

Run

the

program

to

verify

it

has

been

loaded.

34

Chapter

5

ADVANCED

DISK

PROGRAMMING

This chapter

provides

detailed

information

about

DOS

structure

and

disk

utility

commands.

The

utility

commands

provide

the

programmer

with

low-level

func

tions

that

may

be

used

for

special

applications

such

as

special

disk

handling

routines

and

random

access

techniques.

COMMODORE

DISK

OPERATING

SYSTEM

(DOS)

The

DOS

file

interface

controller

is

responsible

for

managing

all

information

be

tween

the

disk

controller

and

the

serial

interface.

Most

disk

I/O

is

performed

on

a

pipelined

basis,

resulting

inafaster

response

to a

requested

operation.

The

file

system

is

organized

by

channels

which

are

opened

with

the

BASIC

OPEN

statement.

When

executed

with

the

OPEN

statement,

the

DOS

assigns

a

workspace

to

each

channel

and

allocates

either

one

or

two

disk

I/O

buffer

areas.

If

either

the

workspaceorthe

bufferisnot

available,

a

NO

CHANNEL

error

is

generated.

The

DOS

also

uses

the

channel

structure

to

search

the

directory,

and

to

delete

and

copy

files.

Three

of

the

eight

buffers

are

used

by

the

DOS

for

the

Block

Availability

Maps

(BAM),

variable

space,

command

channel

I/O,

and

disk

controller's

job

queue.

The

job

queueisthe

vital

link

between

the

two

controllers.

Jobs

are

initiated

on

the

file

sidebyproviding

the

disk

controller

with

sector

header

and

type

of

operation

information.

The

disk

controller

seeks

the

optimum

job

and

attempts

execution.

An

error

condition

is

then

returned

in

plade

of

the

job

command.

If

the

job

is

unsuccessful, the

file

side

re-enters

the

jobagiven

number

of

times,

depending

upon

the

operation,

before

generating

an

error

message.

The

secondary

address

giveninthe

OPEN

statementisusedbyDOSasthe

channel

number.

The

number

the

user

assignstoa

channelisonlyareference

number

thatisusedtoaccess

the

work

areas,

andisnot

relatedtothe

DOS

orderingofchannels.

The

LOAD

and

SAVE

statements

transmit

secondary

35

addresses

of0and

1,

respectively.

The

DOS

automatically

interprets

these

secondary

addresses

as

LOAD

and

SAVE

functions.

Unless

these

functions

are

desired

when

opening

files,

avoid

secondary

addresses

of0and

1.

The

remaining

numbers,

2 through

14,

may

be

used

as

secondary

addresses

to

open

up

to

five

channels

for

data.

Special

OPEN

and

CLOSE

Statements

for

Direct

Access

The

BASIC

statement:

OPEN2,8,4,

"#"

or

OPEN2,8,4,

"#7"

opensachanneltoone

buffer,tobe

used

with

the

block

commands. The

first

available

bufferisallocatedtochannel4in

the

first

example.

The

second

exampleisan

attempttoallocate

buffer7to

the

channel.Ifthe

buffers

are

not

available,

a

NO

CHANNELS

error

conditionisgenerated.

The

explicit

buffer

allocation

canbeusedtoreserve

a buffer

for

position

dependent

code

as in

the

caseofan

execute

command.

You

can

find

the

number

of

the

allocated

buffer

by

executing

a

GET#

state

ment.

The

byte

transmitted

is

the

buffer

number.

The

only

time

you

can

get

a

buffer

numberisbefore

any

writeorread

operationtothat

buffer.

The

CLOSE

statement

clears

the

opened

channel

and

writes

the

BAMtothe

diskette

that

was

last

usedbythat

channel.Itis

recommended

thattoavoid

con

fusion,

you

limit

yourself

to accessing

one

drive

with

any

direct

access

channel.

DISK

UTILITY

COMMAND

SET

The

disk

utility

command

set

consistsofthe

following

commands:

Commands

BLOCK-READ

BLOCK-WRITE

BLOCK-EXECUTE

BUFFER-POINTER

BLOCK-ALLOCATE

BLOCK-FREE

memory-write

memory-read

memory-execute

USER

Abbreviations

B-R

B-W

B-E

B-P

B-A

B-F

M-W

M-R

M-E

U

General

Format

"B-R:"ch,dr,t,s

"B-W:"ch,dr,t,s

"B-E^'ch.dr.t.s

"B-P:"ch,p

"B-A:"dr,t,s

"B-F:"dr,t,s

"M-W"adl/adh/nc/data

"M-R"adl/adh

"M-E"adl/adh

"Ui:parms"

36

Where:

ch

=

the

channel

number

in

DOS:

identical

to

the

secondary

address

in

the

associated

OPEN

statement.

dr

=

the

drive

number:

0

t

=

the

track

number:1through

35.

s

=

the

sector

number,0through

20.

For

each

track

number,

the

sector

rangeisshowninTable

4.

p

=

the

pointer

position

for

the

buffer

pointer.

adl=the

low

byte

of

the

address*.

adh=the

high

byte

of

the

address*.

nc

=

the

number

of

characters:

1

through

34*.

data=the

actual

data

in

hexidecimal.

This

is

transmitted

by

using

the

CHR$

function,

i.e.

CHR$(1)

would

send

the

binary

equivalent

of

hexidecimal

01,

(decimal

1).

i

=

the

index

to

the

User

Table.

parms=the

parameters

associated

with

theUcommand

(optional).

The

values

used

in

conjunction

with

the

memory

commands

exist

in

the

VIC-

1540

as

hexidecimal

values

and

must

be

transmitted

as

CHR$(n),

wherenis

the

decimal

equivalent

of

the

desired

hexidecimal

value.

NOTE:

If

using

variables

the

format

must

have

only

the

command

in

quotes.

For

example:

"B-R:"ch,dr,t,s

correct

"B-R:ch,dr,t,s"

incorrect

To

avoid

confusion,

it

is

good

practice

to

use

this

format

when

using

variables

or

constants.

As

implied

in

the

preceding

format,

these

commands

may

be

abbreviated

to

the

first

character

of

each

of

the

key

words.

Abbreviations

only

are

accepted

for

those

commands

shown

in

lower

case.

The

parameters

associated

with

each

com

mand

are

searched

for

starting

atacolon

(:),

or

in

the

fourth

character

position

ifacolon

is

not

present.

The

example

following

shows

four

ways

that

the

same

block-read

command

may

be

given.

37

NOTE:

Initialize

the

disk

before

the

buffer

readorwrite.

Examples:

"BLOCK-READ:

"

2,0,4,0

"B-R"2,0,4,0

"B-R"2;0;4;0

"B-READ:"2;0;4;0

Parameters

following

the

key

words

within

quotation

marks

maybeseparated

by

any

combination

of

the

following

characters:

Character

Name

Keyboard

Representation

Skip

<

cursor

right

>

Space Space

bar

Comma

The

useofthese

characters

permits

sending

both

ASCII

strings

and

integers.

Parameters

not

within

the

confinesofquotation

marks

shouldbeseparated

by

semi-colons

(;).

In

the

following

discussions,

a

PRINT#is

assumed

in

all

examples.

BLOCK-READ

This

diskette

utility

command

provides

direct

access

to

any

block

on

a diskette

in

either

disk

drive.

Usedinconjunction

with

other

block

commands,arandom

access

file

system

may

be

created

through

BASIC.

This

command

finds

the

character

pointerinthe

0-position

of

the

block.

Whenacharacter

in

this

posi

tion

is

accessed

with

GET#

or

INPUT#,

an

End-or-Identify

(EOI)

is

sent.

This

terminates

an

INPUT#

and

sets

the

Status

Word

(ST)

to

64

in

the

computer.

The

format

"B-R:"ch;dr;t;s

is

illustrated

in

the

following

example.

Example:

"B-R:"5;0;18;0

Reads

the

block

from

track

18,

sector0into

channel5buffer

area.

After

using

BLOCK

READ

to

transfer

the

data

to

the

buffer,

the

data

may

be

transferred

to

memory

by

INPUT*

or

GET#from

the

logical

file

opened

to

that

disk

channel

(i.e.,

using

that

secondary

address).

38

The

Ul

command

described

under

USER

is

similar

to

the

BLOCK-READ

com

mand.

BLOCK-WRITE

When

this

commandisinitiated,

the

current

buffer

pointerisusedasthe

last

character

pointer

andisplacedinthe0positionofthe

new

buffer.

The

buffer

is

then

writtentothe

indicated

blockonthe

diskette

and

the

buffer

pointerisleft

in

position

1.

The

format

"B-W:"ch;dr;t;s

is

illustrated

in

the

following

example.

Example:

"B-W:"

7;0;35;10

Writes

channel7buffertothe

blockontrack

35,

sector

10:

The

U2

command

described

under

USER

is

similar

to

the

BLOCK-WRITE

com

mand.

BLOCK-EXECUTE

This

command

allows

partofthe

DOSoruser

designed

routinestoresideondisk

andbeloaded

into disk

drive

memory

and

executed.

B-EisreallyaB-R

with

an

addition.

The

File

Interface

Controller

begins

executionofthe

contents

after

the

blockisread

intoabuffer.

Execution

mustbeterminated

withareturn

from

the

subroutine

(RTS)

instruction.

Future system

extensions

or

user-created

func

tions

may

implement

this

command.

The

format

"B-E:"ch;dr;t;s

is

illustrated

in

the

following

example.

Example:

"B-E:"6;0;l;10

Readsablock

from

track1,sector10into

channel6buffer

and

executes

its

contents

beginning

at

position

0

in

the

buffer:

BUFFER-POINTER

This

command

changes

the

pointer

associated

with

the

given

channel

toanew

value.

This

is

useful

when

accessing

particular

fields

ofarecord

inablock

or,

if

the

block

is

divided

into

records,

individual

records

may

be

set

for

transmitting

or

receiving

data.

39

The

format

"B-P:"ch,p

is

illustrated

in

the

following

example.

Example:

"B-P:"2;l

Sets

channel2pointer

to

the

beginning

of

the

data

area

in

the

direct

access

buffer:

BLOCK-ALLOCATE

The

appropriate

BAM

is

updated

in

the

DOS

memory

to

reflect

the

indicated

block

as

allocated

(used).

In

future

operations,

the

DOS

skips

over

the

allocated

block

when

saving

programs

or

writing

sequential

files.

TTie

updated

BAM

is

written

to

diskette

upon

the

closure

ofawrite

file

or

the

closure

ofadirect

access

channel.

If

the

block

requested

has

been

previously

allocated,

the

error

channel

indicates

the

block

(increasing

track

and

sector

numbers)

withaNO

BLOCK

error.

If

there

are

no

blocks

available

that

are

greater

in

number

than

the

one

requested,

zeroes

are

displayed

as

track

and

sector

parameters.

The

format

"B-A:"dr;t;s

is

illustrated

in

the

following

example.

Example:

"B-A:"0;10;0

Requests

that

block

(sector)

0

of

track

10

be

flagged

as

allocated

on

the

diskette.

NOTE:

The

error

channel

should alwaysbecheck

when

using

BLOCK

AL

LOCATE,sothatifthe

blockisalready

allocated,

it

will

notbeoverwritten.

If

the

block

is

allocated,

the

error

message

will

also

indicate

the

block.

Example:

INPUT#15

,EN,EM$

JET

JES

Reads

the

and

sector,

respectively,

into

ET

and

ES,

as

suming

that

lfn=15

has

been

previously

OPENed

to

the

disk

error

channel.

BLOCK

FREE

The

BAMisupdatedinmemorytofree

the

block

indicated.

The

diskisup

datedona

closeaspreviously

mentioned.

Neither

the

B-A

nor

B-F

commands

40

require

thatadirect

access

channel

be

open,

since

there

is

no

channel

relation

ship

associated

with

the

operations.

However,

if

the

BAM

is

to

be

updated

on

disk,

these

operations

should

be

used

in

conjunction

the

other

block

com

mands.

The

format

"B-F:"

dr;t;s

is

illustrated

in

the

following

example.

Example:

"B-F:"0;9;20

Freeupthe

block

(sector)20of

track

9.

MEMORY

All

three

MEMORY

commands

are

byte-oriented

so

that

the

user

may

utilize

machine

language

programs.

BASIC

statements

may

be

used

to

access

informa

tion

through

the

MEMORY

commands

by

using

the

CHR$

function.

The

system

accepts

only

M-R,

M-W,

and

M-E:

neither

verbose

spelling

or

the

use

of

the

colon

(:)

is

permitted.

Memory-Write

This

command

provides

direct

access

to

the

DOS

memory.

Special

routines

may

be

down-loaded

to

the

disk

drive

through

this

command

and

then

executed

using

the

MEMORY-EXECUTE

command

or

one

of

the

USER

(U)

commands.

Up

to

34

bytes

may

be

deposited

with

each

use

of

the

command.

The

low

byte

of

the

address

must

precede

the

high

byte

of

the

address.

The

format

"M-W:"adl/adh/nc/data

is

illustrated

in

the

following

example.

Example:

uM-W:"CHR$(00X:HR$(7X:HR$(4)CHR$(32)CHR(0)CHR$(17)-

CHR$(96)

Writes

four

bytes

to

$0700

(decimal

1792):

Memory-Read

The

byte

pointed

to

by

the

address

in

the

command

string

may

be

accessed

with

this

command.

Variables

from

the

DOS

or

the

contents

of

the

buffers

may

also

be

read

with

this

command.

The

M-R

command

changes

the

contents

of

the

error

channel

since

it

is

used

for

transmitting

information

to

the

computer.

The

from

the

error

channel

(secondary

address

15)

transmits

the

byte.

An

INPUT#

should

not

be

executed

from

the

error

channel

afteraMEMORY-

41

READ

command

untilaDOS

command

other

than

oneofthe

MEMORY

com

mandsisexecuted.

The

format

"M-R:"adl/adh

is

illustrated

in

the

following

example.

Example:

"M-R"CHR$(128);CHR$(0)

Accesses

the

byte

located

at

$0080

(decimal

128):

Memory-Execute

Subroutines

in

the

DOS

memory maybeexecuted

with

this

command.

To

return

to

the

DOS,

terminate

the

subroutine

with

RTS

($60).

The

format

"M-E:"

adl/adh

is

illustrated

in

the

following

example.

Example:

"M-E"CHR$(128);CHR$(49)

Requests

the

executionofcode

beginningat$3180

(decimal

12672).

USER

This

command

provides

a

linkto6502

machine

code

accordingtoa

jump

table

pointedtoby

the

special

USER

pointer.

RefertoTable5.The

second

character

in

this

commandisusedasan

indextothe

table.

The

ASCII

character

0

through

9

orAthrough0may

be

used.

Zero

sets

the

USER

pointer

toastandard

jump

table

that

contains

linkstospecial

routines.

The

special

USER

commands

Ul

(or

UA)

and

U2

(or

UB)

can

be

used

to

replace

the

BLOCK-READ

and

the

BLOCK-WRITE

commands.

The

formatofUl

is:

"Ul:"ch;dr;t;s

Ul

forces

the

character

count

(buffer

pointer)

to

255

and

reads

an

entire

block

into

memory.

This

allows

complete

access

to

all

bytes

in

the

block.

The

format

dfU2

is:

"U2:"

ch;dr;t;s

42

U2

writes a

buffertoa

blockonthe

disk

without

changing

the

contentsofposi

tion0as

B-W

does.

This

is

useful

whenablock

is

to

be

read

in

(with

B-R)

and

updated

(B-P

to

the

field

and

PRINT#),

then

written

back

to

diskette

with

U2.

Table3.Standard

Jump

Table

USER

DESIGNATION

Ul

U2

U3

U4

U5

U6

U7

U8

U9

U:

ALTERNATE

USER

DESIGNATION

UA

UB

UC

UD

UE

UF

UG

UH

UI

UJ

FUNCTION

BLOCK-READ

replacement

BLOCK-WRITE

replacement

jump

to

$0500

jump

to

$0503-

jump

to

$0506

jump

to

$0509

jump

to

$050C

jump

to

S050F

jump

to

$FFFA

powerupvector

U3

thru

U9

commands

are

user-defined.

The

locations

jumped

to

are

located

in

the

buffer

areas

of

RAM

and

routines

may

be

written

to

reside

there

and

down

loaded

using

the

M-W

command.

STRUCTURE

OF

DISKETTE

Any

block

onadiskette

may

be

examined

by

using

the

program

DISPLAY

T&S,

provided

on

the

TEST/DEMO

diskette.

Table4.Block

Distribution

by

Track

number

1to17

18to24

25to30

31to35

Block

or

Sector

Range

0to20

0tol8

0tol7

0tol6

Total

21

19

18

17

Tables5through

11

will

assist

the

user

in

interpreting

information

obtained

using

the

DISPLAY

T&S

program.

43

Table5.VIC-1540

BAM

Format

Track

18,

Sector

0.

BYTE

0,1

2

3

4-143

CONTENTS

18,01

65

0

DEFINITION

Track

and

sector

of

first

directory

block.

ASCII

character

A

indicating

1540

format

(Same

as

CBM

4040).

Null

flag

for

future

DOS

use.

Bit

map

of

available

blocks

for

tracks

1-35.

*1=available

block

0 =

block not

available

(each

bit

represents

one

block)

Table6.Directory

Header

Track

18,

Sector

0.

BYTE

144-161

162-163

164

165,166

166-167

171-255

CONTENTS

160

50,65

160

0

DEFINITION

Disk

name

padded

with

shifted

spaces.

Disk

ID.

Shifted

space.

ASCII

representation

for2AwhichisDOS

version

and

format

type.

Shifted

spaces.

Nulls,

not

used.

Note:

ASCII

characters

may

appearinlocations

180

thru

191onsome

diskettes.

44

Table7.Directory

Format

Track

18,

Sector

1.

BYTE

0,1

2-31

34-63

66-95

98-127

130-159

162-191

194-223

226-255

DEFINITION

Track

and

sectorofnext

directory

block.

♦File

entry

1

*File

entry

2

♦File

entry

3

*File

entry

4

♦File

entry

5

♦File

entry

6

♦File

entry

7

♦File

entry

8

*

Structure

of

single

directory

entry

BYTE

0

1,2

3-18

19,20

21

22-25

26,27

28,29

CONTENTS

128

+type

DEFINITION

File

type

OR'ed

with

$80

to

indicate

properly

closed

file.

TYPES:0=

DELeted

1=SEQential

2=PROGram

3=

USER

4=RELative

Track

and

sector

of

1st

data

block.

File

name

padded

with

shifted

spaces.

Relative

file

only: track

and

sector

for

first

side

sector

block.

Relative

file

only:

record

size.

Unused.

Track

and

sector

of

replacement

file

when

OPEN©

is

in effect.

Number

of

blocks

in

file:

low

byte,

high

byte.

45

Table8.

Sequential

Format

BYTE

0,1

2-256

DEFINITION

Track

and

sector

of next

sequential

data

block.

254

bytes

of

data

with

carriage

returns

as

record

terminators.

Table9.

Program

File

Format

BYTE

0,1

2-256

DEFINITION

Track

and

sector

of next

block

in

program

file.

254

bytes

of

program

into

stored

in

VIC

memory

format

(with

key

words

tokenized).

End

of

file

is

marked

by

three

zero

bytes.

Figure5illustrates

an

expanded

view ofasingle

sector

onadiskette

formatted

for

the

1540.

In

addition

to

other

information,

each

sector

contains

a

data

block

consisting

of

256

stored

characters.

Blocks

within

the

same

file

are

linked

to

gether

by

means

ofatwo

character

block

pointer.

By

pointing

to

the

location

of

the

block,

block

pointers

enable

the

system

to

retrieve

data

from

non-

continuous

blocks.

Retrieving

the

first

data

block

withinafile

triggers

a

search

for

the

block

which,

in

turn,

utilizes

block

pointers

to

locate

until

the

entire

file

is

assembled

and

made

available

for

display.

All

PRG,

SEQ,

and

USR

files

utilize

this

format.

A

data

block

is

addressed

by

track

and

sector.A1540

diskette

contains

35

tracks

(or

rings)

numbered1to

35.

The

number

of

sectors

per

track

will

vary

(as

illustrated

in

Table

4)

due

to

differences

in

track

circumference

and

recording

frequency.

The

1540

maintains

a

system

file

on

track

18

which

contains

the

BAM,

diskette

name,

ID,

and

file

directory.

The

BAM,

resident

in

the

first

128

bytes

of

sector

0,

monitors

available

and

occupied

storage

locations

on

diskette.

The

last

128

bytesofsector0are

usedtostore

the

diskette

name

and

ID.

The

file

directory

beginsonthe

sector

1.

46

POINTERSTOLINK

Nv

TOGETHER

ALL

BLOCKS

\

WITHINAFILE

\

SYNC

08

ID1

ID2

TRACK

SECTOR

CHECK

SUM

GAP1

SYNC

07

i

I

254

BYTES

OF

DATA

CHECK

SUM

GAP

2

Fig.

5.

VIC-1540

Format:

Expanded

View

of a

Single

Sector

47

NOTES

Chapter

6

SEQUENTIAL

FILE

A

file

handling

of

sequential

file

which

is

the

most

basic

form

of

the

date

file

is

described

in

this

chapter.

A

sequential

fileisa

file

which

mayberead

onlyinthe

sequenceitwas

written

in.

For

example,afile

with

records,

A,Band

C,

must

be

read

in

the

sequence

of

A,BandCif

they

were

written

in

that

sequence.

The

recordCand

not

be

directly

read

without

reading

the

recordAand

B.

If

it

is

necessary

to

read

the

recordConly,

thenAandBmust

be

read

without

doing

any

work.

In

the

sequential

file,

no

partial

re-write

of

the

record

can

be

made.

Only

change

which

can

be

made

to

the

sequential

file

is

an

addition

of

new

record

to

the

end

of

the

file.

TO

CREATEASEQUENTIAL

FILE

AND

ACCESSING

The

following

steps

are

taken

to

create

a sequential

file

and

accessing.

STEP1

Openafile

for

write

in.

OPEN

2,8,2,

"0:DATE,

S,W"

A

sequential

file

withaname

DATE

is

opened

to

be

written

upon.

Note

the

designation

W

for

write

in at

the

end

of

the

command.

.STEP2Write

in

data

in

the

file

using

PRINT

#.

PRINT#2A$;B$;C$

In

this

case

the

datas

are,3string

variables,

A$,

B$,

and

C$.

STEP

3

Close

the

file

for

the

access

later

CLOSE

2

49

STEP4

Open

the

file

withaname

DATAtobe

read

out.

The

designation

R

for

read

out

may

be

omitted.

OPEN

#2,8,2,

"0:

DATA,

S,R"

STEP

5

Read

in

the

data

from

the

sequential

file

to

the

program

using

INPUT

#.

INPUT#2,X$)Y$,Z$

STEP

6

Check

the

endofthe

filebytheSTvariable.

IF

(ST)

AND

64

THEN

CLOSE

2

EXAMPLE

OF A

SEQUENTIAL

FILE

PROGRAM

An

example

ofasimple

program

to

createasequential

file

is

shown

below.

Records

consisting

of

string

field

and

numeric

field

are

written

in

and

the

con

tents

of

the records

is

displayed

at

the

end

by

typing

END.

1

REM

***************

2

REM

*

EXfiMPLE

3

REM*REfiB&WRITE

4

REM*fl

SEQUENTIfll

5

REM*DflTfl

FILE

9

REM

***************

10

PRINT"3BW»i!INITIRlIZE

DISK."

29

DIMfl*<25>

■

30

DIME<25>

40

OPEN15,8,15,"I0"

60

GOSUB

1000

70

CRS=CHRf<13)

80

PRINT

90

PRINT"

WWRITE

SEQ

TEST

FILES"

95

PRINT

10Q

REM

*.**♦******♦**

101

REM

*

102

REM

*

WRITE

SEQ

103

REM

♦

TEST FILE

104

REM

*

50

105

REM

4************

110

0PEN2,S,2,"@Ci:SEQ

TEST

FILE

..S,U"

115

GOSUB

l&C'O

126

INPUT"fi*,B".:P!,B

13Q

IFR*="END"THEN

168

140

PRINT#2,

fl$","

STP.f

(B>CR#;

.145

GOSUB

1000

15G

GOTO

126

160

CLOSE

2

20Q

REM

*************

201

REN

*

202 REM

*

READ

SEO

203

REM

*

TEST FILE

204

REM

*

205

REM

*************

206

PRINT

207 PRINT"

MREflD

SEQ TEST

FILES"

208

PRINT

210

OPEN2,B,2,"0:SEQ

TEST

FILE

,S,R"

215

GOSUB

1000

220

INPUTt2,fl$<I),B<I)

224

RS*ST

225

OOSUB

1000

230

PRINTfif<I),Ba>

240

IFR

S-64

THEN

300

250

IF

RSO0

THEN

400

260

1*1+1

270

GOTO

220

300

CLOSE

2

310

END:

400 PRINT"

IBRDMDISKIBTRTUSMI

SIB"

RS

410

CLOSE

2

420

END

1000

REM

************

1601

REM

*

1002

REM

*

REBD

1003

REM*THE

ERROR

1004

REM

*

CHRNNEL

1005

REM

*

51

1886

REN

♦♦*****♦»***

1818

INPUT#13,EN,EM$,ET,E$:

1828

IF

EN»8 THEN

RETURN:

1838

PRINT"iniflERROR

ON

DISK"

1048

PRINT"rEN,EM*,ET,ES"r

1858

CL0SE2

1068

END

52

Chapter

7

RANDOM

FILE

A

random

access

fileiscreated

with

the

BLOCK

and

USER

commands

described

in

Chapter

5-Adranced

Disk

Programming.

DATA

FLOW

IN

RANDOM

FILE

In

the

random

access

file

the

data

can

notbeas

simply

writteninor

read

from

as

in

the

caseofa

sequential

file.

Itisnecessarytounderstand

the

data

flow

between

the

computer,

buffer

and

disk

driveinordertotransfer

the

datainthe

random

access

file.Itcanbeillust

ratedasFig.

6.

Channel

5

OPEN

5,8,15

PRINT#5,"B-W";3;0;6;4

Transfer

the

data

from

the

buffer

to

the

computer

Channel

3

OPEN

4,8,3,

"#7"

PRINT

#4,

A$;

CHR$(44)I;

CHR$(13)

Writeinthe

data

from

the

computer

into

the

buffer

move

the buffer

pointer

PRINT#5,"B-P"3;120

»

i

Disk

Drive

Buffer

Computer

f

\

move

the

buffer

pointer

PRINT#5,"B-P"3;120

Transfer

the

data

from

the

disk

to'

the buffer

Read

in

the

data

from

the

buffer

to

the

computer

PRINT#5,"B-R";3;0;6;4

INPUT

#4,

A$,

I

Fig.

6.

Data

Flow

between

Computer,

Buffer

and

Disk

Drive

53

The

above

can

be

more

specifically

described

as:

STEP1.

Openafile

Disk

File

OPEN

5,8,15

'—

Command&Error

Channel

-Device

Number

-Logical

File

Number

Buffer

File

OPEN

4,8,3,

"#7"

'—Buffer

Number

-Channel

Number

-Device

Number

-Logical

File

Number

STEP

2.

Move

the

buffer

pointer

PRINT#5"B:P:"3;120

L'—Pointer

Position

—Channel

Number

of

(§)

SettingofBlock

Pointer

STEP

3.

Place

the

data

in

the buffer

PRINT

#4,

A$;

CHR$(44);

I;

CHR$(13)

Logical

File

Number

of

(

Comma

Carriage

Return

-Variables

STEP

4.

Transfer

the data

from

the

buffer

to

the

disk

PRINT^,"B-W:"3;0;6;4

Logical

File

Number

of

@

Write

•—Sector

number

-Track

number

Drive

number

-Channel

Number

of

(§)

54

STEP

5.

Transfer

the

data

from

the

disk

to the

buffer

PRINT#5)"BTR:"3;0;6;4

Logical

File

Number

of

(A/

Read

Out—I

L-

Sector

Number

Track

Number

Drive

Number

Channel

Number

of

STEP

6.

Move

the buffer pointer

PRINT

#5,

"B-P:"

3;

120

Logical

File

Number

of

®J

-Pointer

Position

Channel

Number

of

(B)

Setting

of

Block

Pointer

STEP

7.

Take

out

the

data

from

the buffer

INPUT#4,A$,1

Logical

File

Number

of (By

Variables

EXAMPLE

OF

USING

RECORD

NUMBER

More

practical

program

which

uses

variables

will

be

as

follows:

It

assumes

OPEN

15,

8,

15

and

OPEN

CH,

8,

CH,

"#"

and

uses

Ul

and

U2

instead

of

B-W

and

B-R.

5166

5185

516S

5110

5120

5130

5140

5150

5160

5180

5190

REN

***'**3|e*#***#*sl**#******

REM*FDD

BLOCK

REflD

*

REM

*#*#**#***#**#*♦*******

GQSUB5330

print#i5,"U1:";ch;fb,ft/fs

print#15/"b-p:";ch;fp

GOSUB5270

FORFI=1TOFX

IHPUT#CH,FB$(FI.):

55

520©

REM

*#*************♦*****•+•*

5281

REM*FDD

BLOCK

WRITE

*

5292

REM

******♦♦**#***♦***+•+***

5210

G0SUB5339

5220

PRINT#15

>"B-P

=";CH;

FP

5230

FORFI=1TOFX:

PRIHT#CH,

FBI-<FI

>■;

£HR*<13),=NEXT

5240

PRINT*15>"U2:";CH;FD;FT;FS

5250

GOSUB5270

5260

RETURN

5270

REM

♦**♦**♦+**♦*****♦•*♦*♦•**

5275

REM

*

ERROR

CHECK

*

527S

REM

**###♦**♦***#***#**♦***

5280

INPUT#15,EN,EM*,ET,ES

5290

IFEN=0THENRETURN

5390

PRINT"ERROR

STflTUS:",EN;EM*;ET;ES

53101HPUT"CONTINUE?">V*:IFY$="V"THEHRETURN

5320 STOP

5322

REM

**##******#*#**********

5324

REM*SET

TRflCK&SECTOR

*

5326

REM

***********************

5330

IFF<358THENF1=0:F2=22

=

F3=1=GOTO5370

5340

IFF>357RNDF<471TRENF1=357:F2=20

=

F3=19:GOTO5370

5350

IFF*>471RNDFO88THENF

1=4?1-F2=19:

F3=25:

G0T03378

5360

IFF>580THENF1=580:F2=18:F3=31

5370

FT=INT<<<P-F1)-1>/<F2-1))+F3

5380 FS=F-F1-<FT-F3)*F2+<FT-F3-1)

5390

RETURN

Where:

CH=Channel

number

FD=Drive

number

FP=Buffer

pointer

The

line

numbers

5270

to

5320

in

the

above

are

the

error

check

routine.

Also

indicated

in

above

by

GOSUB

5330

isasubroutine

which

is

for allocating a

sectorinthe

disk.

A

track

and

sector

mustbedesignated

in

the

random

access

whichisrather

troublesome

and,

therefore,

a

concept

of

record

number

is

used

here

to

reduce

the

burden

of

the

programmer.

For

example,

serial

numbers

as

shown

in

Table

below

are

assignedtothe

sector0in

the

track1to

the

sector16of

the track

35,

in

VIC-1540.

These

serial

numbers

are

called

as

the

record

number,

which

is

in-

56

dicated

byFin

the

subroutine

starting

from

the

line

number

5330

in

the

above

example.

WhenaF

number

is

designated

and

this

subroutine

is

called,

the

corres

ponding

track

and

sector

are

allocated

automatically.

The

directory

will

not

be

destructed

as

the

track

18

has

been

avoided.

Table

10.

Allocation

of

Record

Number

Track

Number

1to17

18

to

24

25to30

31to35

Sector

0to20

Oto

8

0tol7

Oto

16

Number

of

Sector/Track

21

19

18

17

Record

No.

1-357

358471

478-579

586-664

EXAMPLE

OFARANDOM

FILE

PROGRAM

A

simple

program

has

been

made

using

method

to

createarandom

access

file

described

above.

This

program

can be used

for

the

preparation,

deletion

and

inquiry

of

an

address

list.

Line

number

line

number

line

number

Line

number

Line

number

line

number

50

100

200

300

5100

5200

-

76

-

190

-

280

-

390

-5190

-5260

Job

menu.

Creationoffile

Making

deletion

to

the

file

Search

processirig

File

input

routine

File

output

routine

16

REM

******♦****##*****#**#*

12

REM*RRNDOM

FILE

EXRMPLE

*

14

REM

##*#♦##♦♦*♦#*♦♦#**#*#**

16

BIMI$<664>:FD=

18

PRINT'TMW-

20

PRINT"

BINSERT

DRTfl

SHEETS"

22

PRINT"

:

";

24

PRINT"WW

STflRT

PRESS

rS'B"

26

GETP*:IFP*O"S"THEN26

28

0PEN15,8,15,"16":0PEN2,8,2,"#'

38

PRINT"3M-

II

>

32

PRINT"INDEX

FILE

OPERATION"

34

PRINT"

57

36

INPUT"W

MEN

SHEET?

NIMH"

;0$=PRINT'S"

38

IF0*="N"THEN46

48

IF0*O"V"THEN36

42

PRINT:PRINT"

WflIT!":FORI=1TO664

44

PRINT"

>fr

»§mm*M*Mf.

45

PRINTI*

=NEXT:GOTO50

46

OPEN5,8,5,"0:INDEX,S,R

4?

FORI=1TO664:INPUT#5,

4S

PRINT"

»TXtiMRl«}!MO»»ai»

49

NEXTI:CLOSES

56

PRINT

'TM

52

PRINT"

JOE MENU

54

PRINT"

56

PRINT

53

PRINT"

60

PRINT"

62

PRINT"

IIISII"

I;:I$< I

>='V"

IB91B!"

I;

I$<

I)

l=CREfiTE"

2=DELETE"

3=SEP.RCH"

0=ENH"

64

PRINT"

65

PRINT

66

INPUT"1

,2,3,0

1UM";O*

68

IFO$="0"THENCLOSE15:CLOSES:CL0SE2:END

70

IFO*="1"THEN104

72

IFO*="3"THEN300

74

IFO*O'"2"THES50

76

GOTO200

100

REM

♦*#*#*♦#***♦******♦***#

102

REM*MflSTER

FILE

CREflTE

♦

103

REM

*#*****#*#**#***♦♦*#***

104

PRINTMBW

";

105

PRINT"

MflSTER

FILE

CREflTE"

106

PRINT"

"

107

INPUT"IRECORD

NO.=0IIIB";F

109

IF

F=0THEN170

110

IHPUT'NflME

=.IHI";FB$<1)

120

INPUT"RDDRESS

«.IMH";FB*<2>

130

INPUT"ZIP

=.III!",FEJ(3>

132

INPUT

"TEL

a.HM";FB*<4)

134

INPUT'COMMENT

=.IM!";FB$<5>

140

GOSUB5200

150

58

160

GOTO104

170

OPENS,8,5,"80=INDEX,S

M"

175

FORI=1TO664:PRINT#5,I$<I);CHR*<13);

180

PRINT"

WUUHMKHDM»l»ftUR

IT!

IHIII"

I;I$

185

NEXT:CLOSES

196

G0T074

200 REM

***********************

201

REM

*

MflSTER

FILE

DELETE

*

202

REM

*********************+*

210

PRINT"

ZtiM

■

"

•■

212

PRINT"

MflSTER

FILE

DELETE"

214

PRINT"

"

PRINT

220

INPUT"iRECORD

NO.=031153",

F

230

IFF=QTHEN260

'235

IFI*<F)O"1"THEN220

240I*<F)

=" /"■PRINT"

WKECORD

NO."

F;"

DELETES"

250

GOTO220

260

OPENS,8,5,"SO:INDEX,£,1*1"

265

FOR

I=1T0664:

PRINT#5,1

i-

(I);

CHR*<13

>;

276 PRINT"

*!lS»M?I»W»*Si»lJH

IT!

IllSai"

I;I$<I)

275

NEXT:CLOSES

280

GOTG50

300

REM

***********************

301

REM

*

FILE

SEflRCH

*

302

REM

***********************

310

PRINT

".KM

-";

312

PRINT"

SEflRCH

314

PRINT"

":

PRINT

320

INPUT"1RECORD

NO.=SIIIB'SF

321

IFF=0THEN50

322

IFI$(F)O"1"THEN320

325

GOSUB5100

360

PRINT"NRME=";FB*<1)

370

PRINT"flDDRESS

=

";FB*<2>

330

PRINT"ZIP

=

";FB$<3>

382

PRINT"TEL

=

";FB$<4>

383

PP.INT

"COMMENT=";FB$<5)

385

PRINT"

"

390

GOTO320

59

51S6

REM

******************+**+*

5185

REM*FDD BLOCK

RERL

*

5168

REM

*♦♦*♦**********♦*****+*

5116

G0SUB5330

5120

PRINT#15,

"Ul:

",CH.;FD,F7;F5

5136

PRIHT#15,"B-

P;",CH,FP

5140

G0SUB5276

5150

FGRFI=1TOFX

5160

1HPUT#CH..FB$(FI):

51S0

5209

REM

#.#*♦**#********♦*#*****

5201

REM*FDD-BLOCK

WRITE

*

5202

REM

#******#*******♦*******

5210

GOSUB5330

5220

PRINT#15,"B-P:";CH;

FP

5230

FORFI=1TOFX=PRINT#CH,F£$<FI);CHR$<13)>

■NEXT

5240

PRINT#15,"U2:"iCH;FD;FT;FS

525Q

GOSUB5270

5260

RETURN

5270

REM

******************#****

.5275

REM

*

ERROR

CHECK

*

527S

REM

********#****♦♦♦♦******

5280

INPUT#.l

5..

EH,

EM*

.•

ET,

ES

5296

IFEN=0THENRETURN

5360

PRINT"

ERROR

STflTUS:"

.■

EH;

EM*;

ET;

ES

5310

INPUT'-CONTINUE?";'f't

=

IFV$="V"THENRETURN

5320 STOP

5322

REM

**********if:********+if:*+

5324

REM*SET

TRflCK&SECTOR

*

5326

REM

#*#**#**♦****♦*********

5330

IFFC358THEHF1=0:F2=22

=

F3=1:GOT05378

5340

IFF>357FlHIiF<471THEHFl=357:

F2=20

'•

F3=19:

GOTO5370

5350

IFF>471fiHDF<580THENFl=471:F2=19:F3=25:GOTO5370

5366

IFF>580THENF1=589

=

F2=18:F3=31

5370

FT=INT<

<<P-F1>-1)/(F2-l))+F3

5380

FS=F-F1-<FT-FS)*F2+(FT-F3-1>

5330

RETURN

60

Chapter

8

ERROR

MESSAGES-

PATTERN

MATCHING

FILE

NAMES-

REQUESTING

ERROR

MESSAGES

When

the

drive

indicator

of

the

disk

drive

flashes,

it

indicates

an

error

occurred

in

the

disk

drive.

The

execution

of

the

following

program

displays

the

error

on

the

computer

screen

and

resets

the

device

error

indicator:

10

OPEN

1,8,15

20INPUT#l,A,B$,C,D

30

PRINT

A,B$,C,D

where

A=error

message

number

B$=error

message

C

=

track

D=sector

SUMMARY

OF

DOS

ERROR

MESSAGES

0

OK,noerror

exists.

1

Files

scratched

response.

Not

an

error

condition.

2—19

Unused

error

messages:

shouldbeignored.

20

Block

header

not

foundondisk.

21

Sync

character

not

found.

22

Data

block

not

present.

23

Checksum

errorindata.

24

Byte

decoding

error.

25

Write-verify

error.

61

26

Attempttowrite

with

write protect on.

27

Checksum

error

in

header.

28

Data

extends

into

29

Disk

id

mismatch.

30

General

syntax

error.

31

Invalid

command.

32

Long

line.

33

Invalid

filename.

34

No

file

given.

39

Command

file

not

found.

50

Record

not

present.

51

Overflow

in

record.

52

File

too

large.

60

File

open

for

write.

61

File

not

open.

62

File

not

found.

63

File

exists.

64

File

type

mismatch.

65

No

block.

66

Illegal

trackorsector.

67

Illegal

system

trackorsector.

70

No

channels

available.

71

Directory

error.

72

Disk

full

or

directory

full.

73

Power

up

message,

or

write

attempt

with

DOS

mismatch.

74

Drive

not

ready.

DESCRIPTION

OF

DOS

ERROR

MESSAGES

NOTE:

Error

message

numbers

less

than

20

should

be

ignored

with

the

excep

tionof01

which

gives

information

about

the

numberoffiles

scratched

with

the

SCRATCH

command.

20:

READ

ERROR

(block

header

not

found)

The

disk

controller

is

unable

to

locate

the

header

of

the

requested

data

block.

Caused

by

an

illegal

sector

number,

or

the

header

has

been

destroyed.

21:

READ

ERROR

(no

sync

character)

The

disk

controller

is

unable

to

detectasync

mark

on

the

desired

track.

Caused

by

misalignment

of

the

read/write

head,

no

diskette

is

present,

or

unformatted

or

improperly

seated

diskette.

Can

also

indicate

a

hardware

failure.

62

22:

READ

ERROR

(data

block

not

present)

The

disk

controller

has

been

requested

to

read

or

verifyadata

block

that

was

not

properly

written.

This

error

message

occursinconjunction

with

the

BLOCK

commands

and

indicates

an

illegal

track

and/or

sector request.

23:

READ

ERROR

(checksum

error

in

data

block)

This

error

message

indicates

that

there

is

an

error

in

one

or

more

of

the

data

bytes.

The

data

has

been

read

into

the

DOS

memory,

but

the

check

sum

over

the

data

is

in

error.

This

message

may

also

indicate

grounding

problems.

24:

READ

ERROR

(byte

decoding

error)

The

data

or

header

has

been

read

into

the

DOS

memory,

butahardware

error

has

been

created

due

to

an

invalid

bit

pattern

in

the

data

byte.

This

message

may

also

indicate

grounding

problems.

25:

WRITE

ERROR

(write-verify

error)

This

message

is

generated

if

the

controller

detects

a

mismatch

between

the

written

data

and

the

datainthe

DOS

memory.

26:

WRITE

PROTECT

ON

This

message

is

generated

when

the

controller

has

been

requested

to

write

a

data

block

while

the

write

protect

switch

is

depressed.

Typically,

this

is

caused

by

usingadiskette

withawrite

protect

tab

over

the

notch.

27:

READ

ERROR

(checksum

error

in

header)

The

controller

has

detected

an

error

in

the

header

of

the

requested

data

block.

The

block

has

not

been

read

into

the

DOS

memory.

This

message

may

also

indicate

grounding

problems.

28:

WRITE

ERROR

(long

data

block)

The

controller

attemptstodetect

the

sync

markofthe

after

writingadata

block.Ifthe

sync

mark

does

not

appear

withinapre-deter-

mined

time,

the

error

messageisgenerated.

The

erroriscausedbya

bad

diskette

format

(the

data

extends

into

the

or

by

hardware

failure.

29:

DISKIDMISMATCH

This

messageisgenerated

when

the

controller

has

been

requestedtoac

cessadiskette

which

has

not

been

initialized.

The

message

can

also

occur

ifadiskette

hasabad

header.

30:

SYNTAX

ERROR

(general

syntax)

The

DOS

cannot

interpret

the

command

sent

to

the

command

channel.

63

Typically,

this

is

caused

by

an

illegal

number

of

file

names,

or

patterns

are

illegally

used.

For

example,

two

file

names

may

appear

on

the

left

side

of

the

COPY

command.

31:

SYNTAX

ERROR

(invalid

command)

The

DOS

does

not

recognize

the

command.

The

command

must

start

in

the

first

position.

32:

SYNTAX

ERROR

(long

line)

The

command

sent

is

longer

than

58

characters.

33:

SYNTAX

ERROR

(invalid

file

name)

Pattern

matching

is

invalidly

used

in

the

OPEN

or

SAVE

command.

34:

SYNTAX

ERROR

(no

file

given)

The

file

name

was

left

out

ofacommand

or

the

DOS

does

not

recognize

it

as

such.

Typically,

a

colon

(:)

has

been

left

out

of

the

command.

39:

SYNTAX

ERROR

(invalid

command)

This

error

may

result

if

the

command

sent

to

command

channel

(secondary

address

15)

is

unrecognizable

by

the

DOS.

50:

RECORD

NOT

PRESENT

Result

of

disk

reading

past

the

last

record

through

INPUT#,

or

GET#

commands.

This

message

will

also

occur

after

positioning

toarecord

be

yond

endoffileina

relative

file.Ifthe

intentisto

expand

the

file

by

adding

the

new

record

(withaPRINT#

command),

the

error

message

may

be

ignored.

INPUT

or

GET

should

not

be

attempted

after

this

error

is

detected

without

first

repositioning.

51:

OVERFLOWINRECORD

PRINT#

statement

exceeds

record

boundary.

Information

is

truncated.

Since

the

carriage

return

which

is

sent

asarecord

terminator

is

counted

in

the

record

size,

this

message

will

occur

if

the

total

characters

in

the

record

(including

the

final

carriage

return)

exceeds

the

defined

size.

52:

FILE

TOO

LARGE

Record

position

withinarelative

file

indicates

that

disk

overflow

will

result.

60:

WRITE

FILE

OPEN

This

message

is

generated

whenawrite

file

that

has

nQt

been

closed

is

being

opened

for

reading.

64

61:

FILE

NOT

OPEN

This

message

is

.generated

whenafile

is

being

accessed

that

has

not

been

opened

in

the

DOS.

Sometimes,

in

this

case,amessage

is

not

generated;

the

requestissimply

ignored.

62:

FILE

NOT

FOUND

The

requested

file

does

not

exist

on

the

indicated

drive.

63:

FILE

EXISTS

The

file

nameofthe

file

being

created

already

existsonthe

diskette.

64:

FILE

TYPE

MISMATCH

The

file

type

does

not

match

the

file

typeinthe

directory

entry

for the

requested

file.

65:

NO

BLOCK

This

message

occursinconjunction

with

the

B-A

command.Itindicates

that

the

blocktobe

allocated

has

been

previously

allocated.

The

para

meters

indicate

the

track

and

sector

available

with

the

number.

If

the

parameters

are

zero

(0),

then

all

blocks

higher

in

number

areinuse.

66:

ILLEGAL

TRACK

AND

SECTOR

The

DOS

has

attemptedtoaccessatrackorsector

which

does

not

exist

in

the

format

being

used.

This

may

indicate

a

problem

reading

the

pointer

to

the

67:

ILLEGAL

SYSTEM

TORS

This

special

error

message

indicates

an

illegal

system

trackorsector.

70:

NO

CHANNEL

(available)

The

requested

channel

is

not

available,

or

all

channels

are

in

use.Amaxi

mum

of

five

sequential

files

may

be

opened

at

one

time

to the

DOS.

Direct

access

channels

may

have

six

opened

files.

71:

DIR

ERROR

The

BAM

does

not

match

the

internal

count.

There

isaproblem

in

the

BAM

allocation

or

the

BAM

has

been

overwritten

in

DOS

memory.

To

correct

this

problem,

reinitialize

the

diskette

to

restore

the

BAM

in

memory.

Some

active

files

may

be

terminated

by

the

corrective

action.

NOTE:

BAM=Block

Availability

Map

72:

DISK

FULL

Either the

blocks

on

the

diskette

are

used

or

the

directory

is

at

its

limit

of

65

144

entries.

73:

CBMDOSV2.6V170

The

DOS

version

of

the

VIC-1540

is

2.6.

DOS

2.6

and

1.0

(CBM2040/

3040)

are

read

compatible

but

not

write

compatible,

that

is,

the

disk

formatted

on

DOS1.0

may

be

read

but can not

be

written

upon

with

VIC-

1540,

and

the

disk

formattedonDOS2.6

mayberead

but

can

not

be

written

upon

with

DOS

1.0.

DOS2.6

and

2.0

(CBM4040)

are

read

and

write

compatible,

that

is,

the

disk

formattedoneither

version

mayberead

and

written

upon

with

the

other

version.

DOS2.6

and

2.5

(CBM8050)

are

not

read

or

write

compatible,

that

is,

the

disk

formatted

on

either

version

can

not be

readorwritten

upon

with

the

other

version.

This

errorisdis

played

wheneveranattemptismadetowrite

uponadisk

which

has

been

formattedina

non-compatible

format.

This

message

may

also

appear

after

power

up.

74:

DRIVE

NOT

READY

An

attempt

has

been

madetoaccess

the

VIC-1540

Single

Drive

Floppy

Disk

without

any

diskette

presentinthe

drive.

PATTERN

MATCHING

Pattern

matchingoffile

namesisavailable

on

all

Commodore

floppys.

Pattern

matching

uses

the

question

mark

(?)

and

the

asterisk

(*)

to

perform

operations

on

several

files

with

similar

names.

The

asterisk

is

used

at

the

end

ofastring

of

characters

to

indicate

that

the

rest

of

the

name

is

insignificant.

For

example:

could

refertofiles

named

or

FIL*

FIL

FILE1

FILEDATA

FILLER

or

any

other

file

name

starting

with

the

letters

FIL.

The

question

mark

may

be

used

anywhere

within

the

string

of

characters

to

in

dicate

that

the

character

in

that

particular

position

should

be

disregarded.

For

example:

66

?????

.SRC

could

refer

to

files

named

TSTER.SRC

or

DIAGN.SRC

or

PROGR.SRC

but

not

SRC

.FILES

Both

the

characters

and

the

position

of

the

characters

are

significant.

The

question

mark

and

asterisk

maybecombinedinmany

ways:

does

not

make

sense

because

the

question

marks

areinan

area

whichisinsignifi

cant

(because

of

the

asterisk).

P???FIL*

will

access

files

with

the

names

PET

FILE

or

PRG

FILE-32

or

POKEFILES$$

or

any

other

files

starting

withPand

having

FIL

in

positions

5-7.

SCRATCH

with

pattern

matching

should

be

used

carefully,

since

multiple

files

will

be

scratched.

LOAD

will

load

the

first

file

which

fits

the

pattern

matching.

OPEN

with

pattern

matching

maybeusedtoopenanexisting

file,inwhich

case

the

first

existing

file

encountered

which

fits

the

description

willbeopened.

However,

OPEN

should

notbeused with

pattern

matching

when

creating

a

new

file.

Never

use

RENAME,

SAVE,orCOPY

for

pattern

matching

sinceanerror

condition

will

result,

if

attempted.

67

68

APPENDIX

The

following

isalist

of

the

programs

contained

on

the

TEST/DEMO

diskette.

o

m

4

6

14

4

9

5

13

689

tTni-nmiflrnnranrn

"DIR"

"VIEW

BRM"

"DISPLRY

T&S"

"CHECK

DISK"

"PERFORMRNCE

TEST"

"SEQUENTIRL

FILE"

"RRNDOM

FILE"

BLOCKS

FREE.

Ha

PRG

F'RG

PRG

F'RG

DIR

simplifies

the

commands

for

the

display

of

the

disk

directory

or the

disk

operation.

VIEW

BAM

will

read

the

BAM

on

VIC-1540

diskette

and

display

on

the

VIC-

1001

personal

computer.

It

isamatrix

type

map

with

the

sector

numbers

on

the

vertical

axis

and

the

track

number

on

the

horizontal

axis.

The empty

blocks

are

displayed

brightly

and

the

used

blocks

are

displayed

dark.

Because

of

the

formatting

of

VIC-1540,

sector

19

on

is

not

persent

on

tracks

18

to

24,The

VIEW

BAM

program

will

show

these

blocks

as

allocated.

DISPLAY

T&S

will

show

the

users

any

block

of

information

fromadiskette

(including

the

directory

and

BAM)

to

the

screen

or

printer

in

both

ASCII

and

hexidecimal.

(Refer

to

Chapter

5.)

CHECK

DISK

will

performavalidateona disk

then

identify

blocks

that

can

not

be

read

by

the

disk.

This

is

useful

for

detecting

a

damaged

disk.

PERFORMANCE

TEST

performsacheck

outonthe

performance

of

VIC-1540.

SEQUENTIAL

FILE

is

an

example

of

how

to

write

and

readasequential

file

data.

(Refer

to

Chapter

6.)

RANDOM

FILEisan

exampleofdirect

access

file

handling

using

BLOCK

and

USER

commands.

(Refer

to

Chapter

7.)

69

I.DIR

4

0PEN2,8,15

5

PRINT"33":G0T0

10000

10

20

4u

GET#l,fi*,B*

59

C=8

60IFfl$OIIU

THEN

C=fiSC<R$)

70IFB$O1M1

THEN

C=C+flSC<B$)*256

80

PRINT"flia"MID$<STR$<C),2);TRB<3>;

"S2"i

90

GET#1>B$:IF

STO0

THEN 1000

1U0IFB*OCHR$<34>

THEN

90

110

GET#1,B*=IF

B$OCHR$<34)THEN

PRINTED;-GOTQlID

120

GET#1,B$:IF

B*=CHR$<32)

THEN

120

130

PRINT

TflB<18);:C$=IMI

140

C$=C*+B$--GET#1,B*:IF

B$Oni1

THEN

140

150

PRINT"Iia11LEFT$<C*,3>

160

GET

T$:IF

TOO"11

THEN

GOSUB

200Q

170IFST=0

THEN 30

1000

PRINT"

BLOCKS

FREES"

1010

CLOSEl:GOTO

10000

2800IFT$="Q"

THEN

CLOSED

END

2010

GET

T$-IF

T$=""

THEN

2000

2020

RETURN

4000

REM

DISK

COMMflND

4010

C$="":PRINTI1>M;

4011

GETB$:IFB$=IM1

THEN4011

4012

PRINTB$;:IF

B$=CHR$<13>

THEN

4020

4013

C*=C$+B$:GOTO

4011

4020

PRINT#2,C$

5008

PRINT"51";

.*•.•■

5010

GET#2,fl$:PRINTfl$;:IF

fl$OCHR$(13>GOTO5010

5020

PRINT"*"

10000

PRINT

"D-DIRECTORY"

10CU0

PRINT

">-BISK

COMMflND"

•

10020

PRINT

"Q-QUIT

PROGRflM"

10030

PRINT

"S-DISK

STflTUS

"

10100

GETfi*:IFfl$=""THEN10100

10200IFfl$="D"

THEM

10

10300IFR$=".(tORfl$-">11ORfl$=">"

THEN

4000

10310IFfl$="Q"

THEN

END

1032OIFfi*="S"

THEN

5Oo0

19539

GOTO

10100

2.

VIEW

BAM

100

REM

101

REM*VIEW

BflM

FOR

VIC-1540

*

102

REM

♦*♦♦**♦*******♦**♦*♦*******

105

0PEN15,8;15

110

PRINTtlS/'^^NUI^-'N/fl

N/fl N/fl

N/fl

N/fl":Z4=l

120

0PEN2,8,2/'#"

138

v$

148

X$

150

DEF

FNS<Z>=2t<S-INT<S/8>*8>

RND

<SB<INT<S/8>>)

70

160

PRINT#15,"Ui:";2;0;i8;0

170

PRINT#J5,"B-P";2;l

1S0

PRINT11:!1;

19Q

V=22:X=l:GOSUB430

280

FORI=0TO20:PRINT:PRINT"mMRIGHT$<STR$<I)+"

",3>;:NEXT

210

GET#2,flS

■

220

GET#2,fl$

230

GET#2,fi*

240

TS=0

250

FORT=1TO17:GOSUB450

266

V=22:X=T+4:GOSUB430:GOSUB540:NEXT

278

FORI=1TO2000:NEXT

=PRINT"3"

286

V=22:X=l:GOSUB430

290

FORI=0TO20

=

PRINT•PRINT11T]I1RIGHT$<STR$<I)+11

",3);

:NEXT

300

F0RT=18T035

310

GOSUB450

320

V=22:X=T-13:GOSUB430•GOSUB540•NEXT

330

FORI=1TO1000-NEXT

34Q

print"jmmr

350

PRINT#15/'B-P";2;144

360

N*=IMI

:FORI=lTO20:GET#2,fl$-N$=N$+fl*:NEXT

376

PRINT"

"N$"

"TS-17;"BLOCKS

FREE"

3SQ

FORI=1TG4000:NEXT

330

PRINT"?]"

400

INPUT-'MUWWiaflNOTHER

DISKETTE

NIIIG";R*

410

IFfl$="V"THENRUN

420

IFWCV'THENEND

430

PRINTLEFT*<V$,V>LEFT$(X$,

X>

"II";

440

RETURN

456

GET#2>SC$:SC=RSC<RIGHT$<CHR$<0)+SC$,1)>

460

TS=TS+SC

470

GET#2,fi$:lFfl$=""THENfl$=CHR$<0>

480

SB<0)=flSC<fl$>

490

GET#2ifl*f-

IFfl$=""THENfl$=CHR$<0)

500

SB<l>=RSC<fl$>

510

GET#2>fl$:IFfl$=n"THENfl$=CHR$<0)

520

SB<2)=nSC<fl$>

530

RETURN

540

PRINT":?H"RIGHT$<STR$<T>.

1>;

"im";

550

REM

PRINTT"

"SC"

"SB<0>"

"SB<l)n

nSB<2)=CHR$<0)

560

IFT>24flNBS=13THEN:PRINTMII)*':NU^,Z4,l);

:GOTO660

570

FGRS=0TO20

530

1FT<18THEN620

590

IFT>30RNLS=17THEN:PRINTMID$<NU$.Z4,1);:GOTO660

6O0

IFT>24flNDS=13THEN:PRlNTMID*<NU^Z4>l>j

-GOTO660

610

IFT>24mNDS=19THENPRINTMID$<NU$,Z4>1);:GOTG660

620

IFT>17flNDS=20THENPRINTMID$<NU*,Z4,1);

^Z4=Z4+1:

639PRINT"a11;

640IFFNS'.:S)=0

THEN

PRINT"+M;

•G0TG66Q

659

PRINTIIB+";

:REHRIGHT$(STR$<S)/

1>;Z4,1>;

:G0T072

fA#

PRINT'TIB";

6?d

RETURN

71

3.

-Dl

SPLAY

T

& S

100

REN******************************

110

REM*

DISPLRV

flNV

TRfiCK%SECTOR

*

120

REM*ONTHE

VICTOTHE

SCREEN

*

130

REM*ORTHE

VIC PRINTER

*

140

REM******************************

150

print":hm

••;

160

print»displrv

block

contents";

163

PRINT"

"••

170

REM******************************

180

REM*

SET

PROGRRM

CONSTflNT

*

130

REM******************************

200

SP$="

":NL*=CHR*<0):HX$»"0123456789RBCDEF"

210

FS$=""-F0RI=:64

TO

95:FS$=FS$+"Sl'+CHR$a>+11!"

'NEXT

I

220

SS*="

"-FOR

1=192TO223'SS*eSS$+"Sll+CHR$+llI"

-NEXT

I

240 DIM

R$<15>,NB<2>

251

D*»"0"

253

PRINT"

ftKREENXIIIIIIIIIOR

XHSPWINTER"

254

OETJJflF

JJ$=""

THEN254

255IFJJ$="S"THENPRINT"

HSBBCREENSS"

256IFJJt»"P"THENPRINTu

WSIPRINTERS!11

260

0PEN15,8,15/'r'+D*'GQSUB

650

265

0PEN4,4,7"

276

OPEN

2,8,2,

"r"GOSUB

650

230

REM******************************

290

REM*

LORD

TRRCK

RND

SECTOR

*

306

REM*

INTO

DISK

BUFFER

*

310

REM******************************

320

iNPurfcirrRRCK,

sector11

;t,s

330IFT=0ORT>35

THEN

PRINT#15/lI"Di'CL0SE2-CL0SE4:CL0SE15'-PRINTllEND"-EN

340IFJJ^'S"

THEN

PRINT"»WTRRCKIIT"

SECTOR1^11*!"

341IFJJ*=»"P"

THEN

PRINT#4-PRINTS/'TRRCK'^11

SECT0RMS:PRINT#4

350

360

REM******************************

370

REM*

RERD

BVTE0OF

DISK

BUFFER

*

390

REM******************************

400

PRINT#15/'B-P:2,r'

410

PRINTftlS,"M-R"CHR$<0)CHR$(6>

420

GETttl5,fi$<0)>.IFR$<0>=IMITHENR$<0>=NL$

423IF.JJ$="S"THEN430

430IFJJ$a"P"THEN460

431

REM******************************

432

REM*

RERD&CRT

DISPLRV

*

433

REM*

RESTOFTHE

DISK

BUFFER

*

434

REM******************************

436

K»r-NBa>=RSC<R*<0>)

43Q

FOR J=0TO63-IF

J»32 THEN

GOSUB

710'IF

Z*="N"THEN

J«80-GOTO

458

440

FOR

I*K

TO 3

442

GET#2,fl*<I)-IF

fi$<I)»IMI

THEN

R$<I)«NLi

444IFK*l

RND

I<2

THEN

NB<2)*RSC<R$<D)

446

449

R$=""'•B$="•"•N=J*4•GOSUB

790'

fl$*fl$+»

:

»

456 FOR

1=0TO3:N=flSC<fi*>:G0SUB

790

452

C$=fl*a>'-GOSUB

850'Bt=Bf+C$

454

JJ$="S"

THEN

PRINTR$B$

453

72

460

REM******************************

462

REM*

RERD&PRINTER

DISPLRY

*

464

REM******************************

466

K-fNB(l)-RSC<R$<0))

463

FOR J-0TO15

470

FOR

I»KTO13

472

0ET#2,flf(I):lF

fl$(I)-IMI

THEN

Rf»Nl*

474IFK«l

RND

,I<2

THEN

NB<2>-fiSC<fl$>

476

478

R*«"H•

B*«"■":N-J*16'•OOSUB

790:

fi$«fl$+"

*•

"

480

FOR

I«0TO15:H"RSC<Rt<X»'-G0SUB

790:IF

Z*»"N"THEN

J«40'GQTO

371

432

C*»R*a>:

OOSUB

850:B*«Bt+C*

434

436IFJJ*-"P»

THEN

PRINT#4,fl$B$

433

571

REM********#*****#*******#**##«**

572

REM* NEXT

TRRCK

RND

SECTOR

#

573

REMm*mm*mmiMi***********

575

PRINT"NEXT

TRRCK

RND

SECT0Rl(NB<l)NB<2)

MM"

536

PRINT"DO

VOU

WRNT

RND

SECTOR"

590

GET

Z$-IF

Z$=""

THEH590

600IFZ*-^11

THEN

T-NB(1)--S«NB<2>:GOTO330

610IFZ$=»"N"

THEN

320

620

GOTO

590

630

REM******************************

649

REM*

SUBROUTINES

*

650

REM******************************

660

REM*

ERROR

ROUTINE

♦

670

REM******************************

630

INPUT#15,EN,EM$,ET,ES-IF

EN=0

THEN

RETURN

690

PRINT"3DISK

ERRORS"EN>EM*,ET,ES

700

END

710

REM******************************

720

REM*

SCREEN

CONTINUE

MSSG

♦

730

REM******************************

740

PRINTM»MIICONTINUE<V/N>3"

750

GETZ^IF

Z*«IMI

THEN

750

760IFZ$="N"

THEN

RETURN

770IFZ$O"V"

THEN

750

780

PRINT'TJTRRCK11

T"SECTOR"S

"T'RETURN

790

REM******************************

300

REM*

DISK

BVTETOHEX

PRINT

*

810

REM******************************

820

Rl=INT<N/16>:R*«fi*+MID$<HX$,Rl+l,l>

830

R2=INT<N-16*fll):fi*»fi*+MID$<HX$,fi2+l,l>

840

RisRt+SP**.

RETURN

850

REM******************************

860

REM*

DISK

BVTETORSC

DISPLRV

*

870

REM*

CHRRRCTER

♦

330

REM******************************

890IFRSCCC$><32

THEN

C*»"

"-RETURN

910IFRSC<C$X128ORRSC<C$»159

THEN

RETURN

920

C$=MID$<SS$,3*<fiSC<C$)-127>,3>:RETURN

73

4.

CHECK

DISK

1

REM

CHECK

DISK—VER

1.4

2

BN=8:REM

FLOPPV

DEVICE

NUMBER

5

DIMT<100>:DIMS<100):REri

BflD

TRflCK,

SECTOR

flRRflY

9

PRINTMBKW

";

19

PRINT"

CHECK DISK

PROGRRM"

12

PRINT"

"

20

D$="0"

39

0PEN15,DN,15

35

PRINT#15,"y"D*

45

N/i=RND<TI)*255

50

fl$="":

FORI=:1TO255

=

fl*=fl*+CHR$<255flNIKI+N/i)):

GOSUB900

70

0PEN2.DN,2.II#"

80

PRINT:PRINT#2,fi$;

85

T=i:S=0

90

PRINT#15,"B-fl:"D*;T;S

100

INPUT#15,EH,EM$,ET,ES

110

IFEN=0THEN130

115

IFET=0THEN200:REM

END

120

130

134

NB=NB+i:PRINT"

CHECKED

BLOCKS"NB

135

PRINT"

TRflCK

liHI"T;"

SECTOR

IHm"S".Tl"

140

INPUT#15>EN,EM$,ES,ET

150IFEN=0THEN35

160

T(J>=T

S<-J>=S:J=J+1

165

PRINT"MWBflD

BLOCK:III",T;S"S"

170

G0T035

200

PRINT#15,"rD$

210

GOSUB900

212

CL0SE2

215

IF>0THENPRINT")Ttt»»HO

BflD

BLOCKS!

":END

217

0PEN2>DN,2,"#"

213

PRINT"W)«flD

BLOCKS","TRflCK","SECTORS"

220

FORI=0TOJ-1

230

PRINT#15,"B-fl-";D$,T,S

240

PRINT,,T<I),S<I)

250

PRINT"M"J"BflD

BLOCKS

HflVE

BEENflLLOCflTED"

270

CLOSE2=END

900

INPUT#15,EN,EM$,ET,ES

910IFEN=0

THEN

RETURN

920

PRIkr'MHERROR

#"EN,EM$;ET;ES"3"

930

PRINT#15,"I"D*

5.

PERFORMANCE

TEST

1600

REM

PERFORMflNCE

TEST

1.1

1010

:

1020

REM

VIC-1340

SINGLE

FLQPPV

DISK

DRIVE

1630

'

1040

:

1050

OPEN

1,9,15--0PEN13,8i13

1060

LT=35

1070

LT$*STR$(LT)

74

1080

HT=30

1090

PRINT'TJO-

1100

PRINT"D

PERFORMRNCE

TEST"

1110

PRINT"

•'

1120

PRINT

1130

PRINT"

JIINSERT

SCRflTCH"

1140

PRINT

1150

PRINT"

DISKETTEINDRIVE"

1160

PRINT

1170

PRINT"M

PRESS

^RETURN!"

1180

PRINT

1130

PRINT"

WHEN

RERDVM"

1200

FOR

1=0TO50:GET

ft*:NEXT

1.210

GET

R$:IF

fl*OCHR$<13>

THEN

1210

1220

:

1230

•

1.240TI$="000000"

1250

TT=13

1260

PRINT*1,"N0'TEST

DISK,00"

1270

Cl$="ii

DISK

NEW

COMMflND

"

1280

C2$="3M

WRIT

RBOUT80SECONDS"

1290

CC$=C1$+C2$GOSUB

1840

1300IFTKNTTHEN1370

1310

PRTNT"»3VSTEM

IS"

1320

PRINT"H

NOT

RESPONDING"

1330

PRINT"

CORRECTLYTOCOMMRNDS"

1340

GOSUB

1330

1350

"•

1360

:

1370

PRINT"MDRIVE

PfiSS"

1380

PRINT"

MECHRNICRL

TESTW"

1390

TT=21

1400

OPEN

2,3,2,"0=TEST

FILE,S,W"

1410

CC*»"OPEN

WRITE

FILE"

:GOSUB

1840

1450

CH»2:CC$-"MRITE

DRTfl"

:GOSUB

1930

1430

CC$="CLOSE

"+CC$

:GOSUB

1840

1440

OPEN

2,8,2,"0:TEST

FILE,S,R"

1450

CC**"OPEN

RERD

FILE"

-GOSUB

1840

1460

CH=2

:GOSUB

1990

1470

PRINT#1/'S0-TEST

FILE"

1480

CC$="SCRRTCH

FILEW"-TT=1

:GOSUB

1840

1490

••

1510

TT«21

1520

OPEN

4,8,4,"#"

1530

NN5i»<

1+RND<TI

>*254+NNSORND255:

PRINT#1,

"B-P";

4;

1540

NN*-MII:FOR

1-1TO255:NN$«NN*+CHR$<I)

:NEXT

1550

PRINTS

4,NN$;

1560

PRINT*

1/'U2'";4;0;LT;0

1570

CC*="WRITE

TRRCK"+LT$-GOSUB

1840

1580

PPINT#i/'U2-";4;0;i;0

1530

CCS="WRITE

TRRCK

1"

:GOSUB

1840

I600

PRlNT#i/'ur";4;0;LT;0

1610

CC$="RERD

TRRCK"+LT$

:GOSUB

1840

1620

PRINT#l,«Ul:H;4;e:l;0

1630

CCf="RERD

TRRCK

1"

:GOSUB

1840

1640

CLOSE

4

1650

:

1660

'■

75

1678

PRINT

"Ml

UNIT

HflS

PRSSED"

J689

PRINT"

PERFORMflNCE

TEST!"

1690

PRINT-W

PULL

DISKETTE

FROM"

1700

PRINT-S

DRIVE

BEFORE

TURNING"

1710

PRINT"

POWER

OFF."

1720

END

1736

•

1740

••

1750

PRINT"

MHCONTINUE

<V/N)?B";

1760

FOR

1=0TO50-GET

fl$=NEXT

1770

GET

fl$:IF

fl$-M"

THEN

1770

1780

PRTNT

R$"W"

1790IFR*="N"

THEN

END

1800IFfi$»"V"

THEN

RETURN

1810

GOTO

1760

1820

•

1830

■

1840

PRINT

CC*

1850

INPUT*

1,EN,EM$,ET,ES

I860

PRINTTRB<12)"ai'EN;EM$;ET;ES;"SM

1870IFEN<2

THEN

RETURN

1880

PR1NT"M

UNITISFRILING"

1890

PRINT"M

PERFORMflNCE

TEST"

1900

TM$-TI$:OOSUB

1750-TI$=TMi-RETURN

1910

•

1920

•

1930

PRINT-WRITING

DflTfl"

1940

FOR

I«1000TO2000'PRINT#CH,I'NEXT

1950

GOSUB1850

I960

CLOSE

CH-RETURN

1970

••

1980

*■

1990

PRINT"RERDING

DflTR"

2000 GETR*

2810

FOR

1=1008

TO 2000

2020

INPUT*

CH,J

2030IFKM

THEN

PRINT":RERD

ERROR:I"•GOSUB

1850

2040

GOSUB

1350

2060

CLOSE

CH:RETURN

76

-ERRATA-

P12416

P56,

P60

Wrong

TYPE:

OPEN1,8,15/10"

5340

IFF>357ANDF<471

5360

IFF>580THENFl=5

P57

tablelO

P69

P72

25to30

0tol718478-579

31to35

0tol617586-664

DISPLAY

T&S

RANDOM

FILE

410

PRINT#15/M-R"

CHR$(0)

CHR$(6)

Correct

TYPE:

OPEN1,8,15/I0"

5340

IFF>357ANDF<472

5360

IFF>579THENF1=579

25to30

0tol718472-579

31to35

0tol617580-664

These

programs

require

an

expander

RAM.

410

PRINT#15,*M-R"

CHR$(0)

CHR$(5)

CAUTION-

AttemptingtoLOAD

Disk

Progranrs

that

exceed

your

VIC's

memory

area

will

overflow

into

the

screen

area.Toavoid

this

problem

you

should

add

sufficient

memorytoyour

VIC

withanexpander

RAM

cartridge.

1982-06-02

Commodore vic-1540 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual