Commodore 1570, 1571 User Manual

COMMODORE

DISK

DRIVE

1570/71==

Users's

Guide

COMMODORE

DISK DRIVE

1570171

Users's Guide

USERS

MANUAL

STATEMENT

WARNING:

This

equipment

has

been

certified

to

comply

with

the

limits

for

a

ClassBcomputing

device,

pursuant

to

subpart

J of

Part

15

of

the

Federal

Communications

Commission's

rules,

which

are

designedtopro

vide

reasonable

protection

against

radio

and

television

interference

in

a

residential

installation.

If

not

installed

properly,

in strict

accordance

with

the

manufacturer's

instructions,

it

may

cause

such

interference.

If

you

suspect

interference,

you

can

test

this

equipmentbyturningitoff

and

on.

If

this

equipment

does

cause

interference,

correctitby

doing

anyofthe

following:

•

Reorient

the

receiving

antennaorAC

plug.

•

Change

the

relative

positions

of

the

computer

and

the

receiver.

•

Plug

the

computer

intoadifferent

outletsothe

computer

and

receiver

areondifferent

circuits.

CAUTION:

Only

peripherals

with

shield-grounded

cables

(computer

input-

output

devices,

terminals,

printers,

etc.),

certified

to

comply

with

Class

B

limits,

canbeattachedtothis

computer.

Operation

with

non-certified

peripherals

is

likelytoresultincommunications

interference.

Your

house

AC

wall

receptacle

must be

a three-pronged

type

(AC

ground).

If

not,

contact

an

electrician

to

install

the

proper

receptacle.

If

a

multi-connector

boxisusedtoconnect

the

computer

and

peripherals

to

AC,

the

ground

must

be

common

to

all

units.

If

necessary,

consult

your

Commodore

dealer

or

an

experienced

radio-

teievision

technician

for

additional

suggestions.

You

may

find

the

following

FCC

booklet

helpful:

"How

to

Identify

and

Resolve

Radio-TV

Interference

Problems."

The

booklet

is

available

from

the

U.S.

Government

Printing

Office,

Washington,

D.C.

20402,

stock

no.

004-000-00345-4.

FOR

USERS

IN

UK

WARNING:

THIS

APPARATUS

MUSTBEEARTHED

!

IMPORTANT.

The

wiresinthis

mains

lead are

colouredinaccordance

with

the

fol

lowing

code:

Green

and

yellow

Blue

Brown

Earth

Neutral

Live

As

the

coloursofthe

wiresinthe

mains

leadofthis

apparatus

may

not

correspond

with

the

coloured

marking

identifying

the terminalsinyour

plug,

proceedasfollows:

The

wire

whichiscoloured

green

and

yellow

must be

connectedtothe

terminal

in

the

plug

whichismarkedbythe

letterEorbythe

safety

earth

symbol—or

coloured

greenorgreen

and

yellow.

The

wire

whichiscoloured

blue

mustbeconnectedtothe

terminal

which

is

marked

with

the

letterNor

coloured

black.

The

wire

whichiscoloured

brown

must be

connectedtothe

terminal

which

is

marked

with

the

letterLor

coloured

red.

USER 'S MANUAL STATEMENT

WARNING: This equipment has been certified to comply with the limits for a Class B computing device, pursuant

to

subpart J of Part

15

of the

Federal Communications Commission's rules, which are designed

to

pro-

vide reasonable protection against radio

and

television interference

in

a

residential installation.

If

not installed properly, in strict accordance with

the manufacturer's instructions, it may cause such interference.

If

you

suspect interference,

you

can

test this equipment

by

turning

it

off

and

on. If

this equipment does cause interference, correct

it

by doing any

of

the

following:

• Reorient the receiving antenna or

AC

plug.

• Change t

he

relative positions of

the computer and the receiver.

•

Pl

ug

the computer in

to

a differe

nt out

let

so

the computer and

receiver

are

on

different circu

its.

CAUTION: Only peripherals with shield-grounded cables (computer inputoutput devices,

te

rminals, printers, etc.), certified

to

comply with Class B

limits, can

be

attached

to

this computer. Operation with non-certified

pe

ripherals

is

likely

to

result

in

communications interference.

Your house

AC

wall receptacle must

be

a three-pronged type (AC

ground).

If

not, contact

an

electrician

to

install the proper receptacle.

If

a

multi-connector box

is

used to connect the computer and peripherals to

AC,

the ground must

be

common to

all

units.

If

necessary, consult your Commodore dealer or

an

experienced radio-

television technician for additional suggestions.

You

may find the following

FCC

booklet h

elp

ful: "How to Identify

and

Resolve Radio-TV Interference

Problems." T

he

booklet

is

available

from

the U.S. Government Printing

Offi

ce,

Washington, D.C. 20402, stock

no.

004-000-00345-4.

FOR USE

RS

IN

UK

WARNING: TH

IS

APPARATUS MUST BE EARTHED!

IMPORTANT

. The wires in this mains lead are coloured in accordance with the fol·

lowi

ng

code

:

Green

and

yellow Earth

Blue

Neutral

Brown

live

As

the colours of the wires

in

the mains lead of this apparatus may not correspond

wi

th

the coloured marking identifying the terminals

in

your plug. proceed

as

follows;

The wire which

is

coloured green and yellow must be connected

10

the terminal

in

the plug which

is

marked by the letter E or by the safety earth

symbol-or

coloured

green or green and yellow.

The wire

which

is coloured blue

must

be connected

to

the

terminal

which

is

marked

with

the letter N or coloured black.

The wire

which

is

coloured brown

must

be connected to

the

terminal which

is

marked

with

the

letter L

or coloured red.

Disk Drive

User's Guide

1570/1571

by

Commodore Electronics Limited

This manual contains copyrighted and proprietary information.

No

part

of

this publication

may be reproduced, stored

in

a retrieval system, or transmitted

in

any form or

by

any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission

of

Commodore Electronics Limited.

CONTENTS

INTRODUCTION

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

1

PART ONE: BASIC OPERATING INFORMATION

CHAPTER 1:

HOW

TO

UNPACK, SET UP

AND

BEGIN USING THE

1571

....

3

step-by-step instructions

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

3

operating modes

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

5

troubleshooting guide

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

6

simple maintenance tips

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

7

inserting a diskette

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

7

diskette care

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

8

using pre-programmed (software) diskettes

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

9

how to

prepare

a new diskette

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

10

diskette directory

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

11

selective directories

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

12

printing a directory

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

13

pattern matching

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

13

splat files

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

13

CHAPTER 2: BASIC 2.0 COMMANDS

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

14

error

checking

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

14

BASIC hints

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

15

save

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

16

save with replace

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

16

verify

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

17

scratch

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

18

more about scratch

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

19

rename

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

20

renaming

and

scratching troublesome

files

(advanced users)

..........

21

copy

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

21

validate

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

23

initialize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

24

CHAPTER 3: BASIC 7.0 COMMANDS

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

25

error

checking

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

25

save

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

25

save with replace

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

26

dverify

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

27

copy

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

27

concat.

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

28

scratch

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

28

more about scratch

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

29

rename

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

30

renaming and scratching troublesome files (advanced users)

..........

30

collect

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

31

initialize

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

32

CHAPTER 4: DOS SHELL

......•...•......•....•..•..•................

33

language selection

...•...•...•.........•........................

33

primary

menu screen

•...•......................................

33

disk/printer setup

..•.......................................•..•

33

run a program

••...•...........................................

34

format a disk

.••...........................•.....•.............

34

cleanup a disk

.....•....•...•.............................

'

.....

34

copy a disk

•....................•.....•..........•.............

35

copy files

..............•...••..........•...................•..

35

delete files

..............••............................•.......

36

restore files

...........................................•.......

36

rename files

..............................................•....

37

reorder

directory

.......•......................................

37

PART TWO: ADVANCED OPERATION

AND

PROGRAMMING

CHAPTER 5: SEQUENTIAL DATA FILES

........•......................

39

the concept of files

............................................•

39

opening a

file

...............•......•...........................

39

adding to a sequential

file

•...•......•...........................

43

writing

file

data: using

print#

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

43

closing a

file

........•....•............•........................

45

reading

file

data: using

input#

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

46

more about

input#

(advanced users)

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

47

numeric

data

storage on diskette

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

48

reading

file

data: using

get#

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

49

demonstration of sequential files

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

51

CHAPTER 6: RELATIVE DATA FILES

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

53

the value of relative access

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

53

files, records,

and

fields

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

53

file

limits

•....................................................

54

creating a relative

file

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

54

using relative files:

record#

command

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

55

completing relative

file

creation

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

57

expanding a relative

file

.....................................•...

59

writing relative

file

data

..............................•..........

59

designing a relative record

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

59

writing the record

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

60

reading a relative record

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

64

the value

of

index files (advanced users)

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

66

CHAPTER 7: DIRECT ACCESS COMMANDS

............•.............•.

67

a tool for advanced users

......................................•.

67

opening a

data

channel for direct access

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

67

block-read

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

68

block-write

..........•....••..••..•...•............•.....•.....

69

the original block-read

and

block-write commands (expert users)

......

70

the buffer pointer

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

71

allocating blocks

...................•..•..................•..•..

72

freeing blocks

.....•...•..........•.........•............•.....

73

using

random

files (advanced users)

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

73

CHAPTER 8: INTERNAL DISK COMMANDS

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

74

memory-read

....•.......•...•.............•...................

75

memory-write

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

76

memory-execute

..•...•••.........••..•..................••....

77

block-execute

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

78

user commands

.•...•.............•...•...•...............•..•.

79

utility loader

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

80

CHAPTER 9: MACHINE LANGUAGE PROGRAMS

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

81

disk-related kernal subroutines

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

81

CHAPTER

10:

BURST COMMANDS

.•......•..•........................

82

read

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

82

write

.•...•..................•...............•................

83

inquire disk

.....•............•...•............................

83

format

MFM

................................................•.

84

format

GCR

(no directory)

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

85

sector interleave

.................................•.............

85

query disk format

....................................•.........

86

inquire status

..................................•........•......

86

chgutl utility

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

87

fastload utility

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

87

status byte breakdown

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

88

burst

transfer

protocol.

.........•..•..........................•.

89

explanation of procedures

...•...•..•..••......................•.

90

example

burst

routines

..............•.........................•.

91

APPENDICES:

A:

changing the device

number

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

98

B:

dos

error

messages

.............•...............•............

99

C: diskette formats: GCRfMFM

.....•..••....................

'

...

103

D:

disk command quick reference

chart

.................•.......•

112

E: specifications of the

1571

disk drive

...•...•...................

114

F: serial interface information

..•...............................

116

G: disk operating systems: Commodore and CP/M

............•....

118

USER'S MANUAL STATEMENT

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

inside back cover

INTRODUCTION

MAIN OPERATING FEATURES

The

1571

is

a versatile disk drive that handles multiple disk formats and data transfer

rates. Disk formats range from single-sided, single-density

to

double-sided, double-

density. The

1571

can be used with a variety

of

computers, including the Commodore

128, the Commodore 64, the Plus 4, C16, and

VIC

20.

When used with the Commodore

128

Personal Computer, the

1571

offers the

following features:

• Standard

andfast

serial data transfer

rates-

The

1571

automatically selects the

proper data transfer rate (fast or slow) to match the three operating modes

available on the Commodore

128

computer (C128 mode, C64 mode, and CP/M

mode).

• Ability to read and write

in

double-density MFM

format-

This allows access to

the CP/M software libraries

of

other personal computers.

• Double-sided, double-density data

recording-Provides

up

to

339K storage ca-

pacity per disk (l69K per side).

• Special high-speed burst

commands-

These commands, used for machine language programs, transfer data several times faster than the standard or fast serial rates.

When used with the Commodore 64 computer, the

1571

disk drive supports the

standard single-density GCR format disks used with the Commodore

1541,1551,4040,

and 2031 disk drives.

NOTE

CP/M disks are included

in

Commodore 128 carton; CP/M operating information is presented

in

the Commodore 128 user manuals.

HOW THIS GUIDE IS ORGANIZED

This guide

is

divided into two main parts and seven appendices,

as

described below:

PART

ONE: BASIC OPERATING INFORMATION-includes all the information

needed by novices and advanced users

to

set

up

and begin using the Commodore

1571

disk drive.

PART

ONE

is

subdivided into four chapters:

• Chapter I tells you how

to

use disk software programs that you buy, like Perfect

Writer®

and

Jane®.

These pre-written programs help you perform a variety of

activities in fields such

as

business, education, finance, science, and recreation.

If

you're interested only

in

loading

ard

running pre-packaged disk programs,

you

need read no further than this chapter.

If

you

are

also interested in saving, loading,

and running your own programs, you will want

to

read the remainder

of

the guide.

• Chapter 2 describes

the

use

of

the BASIC 2.0 disk commands with

the

Commo-

dore 64 and Commodore

128

computers.

• Chapter 3 describes the use

of

the BASIC 7.0 disk commands with the Commo-

dore 128.

• Chapter 4 describes the use

of

the DOS Shell program, which provides you with a

convenient alternative way to execute disk drive commands. The DOS Shell

is

included on the

1571

test/demo diskette supplied with your disk drive.

PART TWO: ADVANCED OPERATION AND

PROGRAMMING-is

primarily

intended for users familiar with computer programming.

PART

TWO

is

subdivided

into six chapters:

• Chapter 5 discusses the concept

of

data files, defines sequential data files, and

describes how sequential data files are created and used on disk.

• Chapter 6 defines the differences between

sequential and relative data files, and

describes how relative data files

are

created and used on disk.

• Chapter 7 describes direct access disk commands

as

a tool for advanced users and

illustrates their use.

• Chapter 8 centers on internal disk commands. Before using these advanced commands, you should know how to program a 6502 chip

in

machine language

and have access to a good memory map of the 1571.

• Chapter 9 provides a list

of

disk-related kernal ROM subroutines and gives a

practical example

of

their use in a program.

• Chapter

10

gives information

on

high-speed burst commands.

APPENDICES A THROUGH

G-provide

various reference information; for example,

Appendix A tells you how to set the device number through use

of

two switches

on

the

back

of

the drive.

2

PART ONE:

BASIC OPERATING INFORMATION

CHAPTER 1

HOW TO UNPACK, SET UP AND BEGIN USING THE 1571

STEP-BY -STEP INSTRUCTIONS

I. Inspect the shipping carton for damage.

If you find any damage to the shipping carton and suspect that the disk drive may have

been affected, contact your dealer.

2. Check the contents

of

the shipping carton.

Packed with the

1571

and this book, you should find the following: 3-prong electrical power cord, interface cable, Test/Demo diskette, and a warranty card to be filled out and returned to Commodore.

3. Remove the cardboard shipping spacer from the disk drive. The spacer is there

to

protect the inside

of

the drive during shipping. To remove it,

rotate the lever on the front

of

the drive counter-clockwise (see Figure I) and pull out

the spacer.

Figure L Front

of

1571

Disk Drive

POWER DRIVE

LEVER FOR CLOSING DRIVE.

3

4. Connect the power cord. Check the ON/OFF switch on the back

of

the

drive (see Figure

2)

and make sure it's

OFF. Connect the cord where indicated in Figure

2.

Plug the other end into a grounded

(3-prong) outlet. Don't tum the power

on

yet.

Figure 2. Connection of Power Cord and Interface Cables to

1571

POWER CORD

SOCKET

GROUNDED

POWER

OUTLET

SERIAL PORT

CONNECTORS

FOR

INTERFACE

CABLES

4

ON/OFF SWITCH

DIP SWITCHES

FOR CHANGING

DEVICE

NUMBER

5. Connect the interface cable. Make sure your computer and any other peripherals are OFF. Plug either end

of

the interface cable into either serial port on the back of the drive (see Figure 2). Plug the other end

of

the cable into the back

of

the computer. If you have another peripheral (printer or extra drive), plug its interface cable into the remaining serial port on the drive.

6.

Turn ON the power.

With everything hooked up and the drive empty, you can turn on the power to the peripherals

in

any order, but turn on the power

to

the computer last. When everything

is

on, the drive goes through a self test. If all

is

well,

the

green light will flash once and

the red power-on light will glow continuously.

If

the green light continues

to

flash,

there may be a problem. Refer

to

the Troubleshooting Guide.

OPERATING MODES

To achieve maximum compatability between the

1571

and other disk drives, the

1571

has two modes

of

operation that allow

it

to

be used

in

a variety

of

situations.

1541 Mode

When you first turn on the 1571, it powers

up

in

1541

mode. That is,

it

works almost

exactly as a

1541

disk drive, which helps maintain compatability with certain special programs and copy-protected diskettes. Also, many loading routines are dependent upon the 1541-speed internal timing. However, when the drive

is

in

this mode, it can't take

advantage

of

the special

1571

features.

1571 Mode

In

1571

mode, the drive can take advantage

of

such features

as

double-sided

diskettes, MFM-format diskettes, fast data transfer rates, and burst transfer protocol. The

1571

can determine whether or not the host computer can receive fast data transfer and

transmits accordingly.

Mode Selection

As

mentioned above, the

1571

powers up in

1541

mode. However,

it

automatically

shifts to

1571

mode upon the first

of

a fast serial transfer initiated

by

the host (the

Commodore 128). The Commodore 64 and Plus 4 can't perform fast serial transfers on the

serial bus, but you can shift from

1541

to

1571

mode

by

sending the following BASIC

command: OPEN

1,8,15,"U0>Ml".

Although these computers can't directly take

advantage

of

the drive's faster transfer speeds, they can have twice the normal storage.

If

you are using a Commodore

128

and want the

1571

to remain

in

1541

mode,

you

can send the following BASIC command: OPEN 1 ,8,15,

"U0>M0".

The drive will

then remain in

1541

mode until the next power

up

or system reset.

The possible combinations

of

modes with the Commodore

128

and

1571

are shown

below:

C1281l571

modes-Turn

on the drive, then turn on or reset the computer.

5

C128/1541

modes-Tum

on or reset the computer, and when the cursor appears, tum on the drive. In this case, the first disk access will switch the drive

to

1571

mode, so send the BASIC command given on

the previous page

to

lock the drive into

1541

mode.

C64!1571 modes

-Tum

on the drive, then tum on or reset the computer and type:

GO 64

C64!1541 modes

-Tum

on the drive, then hold down the COMMODORE key

while you tum on or reset

the

computer.

TROUBLESHOOTING GUIDE

Problem Red power-on

indicator not lit

Green drive light flashing

Programs won't load and the

computer says

"DEVICE

NOT PRESENT

ERROR"

Programs won't load, but the computer and disk drive

gi ve no error message

Possible Cause

Power not

ON

Power cable not

plugged

in

Power off to wall outlet

Drive failing its self test

Interface cable not well

connected or drive not ON

Switches on back

of

drive

may not

be

set for correct

device number Another part

of

the system

may

be

interfering

6

Solution

Make sure ON/OFF switch is

ON

Check both ends

of

power cable to be sure they are full y inserted

Replace fuse or reset circuit

breaker

in

house

Turn the system off for a moment then try again. If the light still flashes. turn the drive off and on again with the interface cable

disconnected.

If

the problem persists. contact your dealer. If unplugging the interface cable made a difference. make sure the cable is properly connected. If that doesn't work, the problem

is

probably

in

the cable itself

or somewhere else

in

the

system Be sure the cable

is

properly connected and the drive is

ON

Check Appendix A for correct setting

to

match

LOAD command Unplug

all

other machines on the computer. If that cures it, plug them

in

one at a time. The one just added when the trouble repeats

is

most likely the problem Trying

to

load a machine language program into BASIC space will cause this problem

TROUBLESHOOTING GUIDE (continued)

Problem

Programs

won't

load and

green dri

ve

light flashes

Possible

Cause

Disk error

Solution

Check the error channel

to determine the error, then follow the advice

in Appendix B to correct it. The error channel

is

explained

in

Chapters 2 and 3

(Be sure to spell program names correctly and include the exact punctuation when loading the programs)

Your programs load OK, but commercial programs and those from other 1571s don't

Your programs that used

to

load,

won't

anymore, but programs saved on newlyformatted diskettes will

Either the diskette

is

faulty,

or your disk drive

is

misaligned

Older diskettes have been damaged

The disk drive has gone out of

alignment

SIMPLE MAINTENANCE TIPS

1.

Keep the drive well ventilated.

Try another copy

of

the

program.

[f

several programs from several sources

fail

to

load, have your dealer align your disk drive

See the safety tips for

diskettes in the next section.

Recopy from backups Have your dealer align

your disk dri

ve

A couple

of

inches

of

space to allow air circulation on all sides will prevent heat from

building up inside the drive.

2. Use Commodore diskettes. Badly-made diskettes can cause increased wear on the drive's read/write head. If you're

using a diskette that

is

unusually noisy,

it

could be causing added wear and

should be replaced.

3. The

1571

should be cleaned once a year

in

normal use.

Several items are likely

to

need attention: the two read/write heads may need cleaning

(with

91

% isopropyl alcohol on a cotton swab). The rails along which the head moves

may need lubrication (with a special molybdenum lubricant, not oil), and the write protect sensor may need

to

be dusted. Since these chores require special materials or

parts, it is best

to

leave the work to an authorized Commodore service center. If you want to do the work yourself, ask your dealer for the appropriate materials. IMPORT ANT: Home repair

of

the

1571

will void your warranty.

INSERTING A DISKETTE

To insert a diskette, first open the drive door by rotating the door lever counter-

clockwise one quarter

tum

until

it

stops, with the lever parallel

to

the horizontal slot

in

the

front

of

the drive.

Grasp the diskette by the side opposite the large oval access slot, and hold it with the

label up and the write-protect notch to the left (See Figure 3). Now insert the diskette

by

pushing it straight into the slot, the access slot going

in

first and the label last. Be sure the

diskette goes

in until it stops naturally. You shouldn't have

toforce

or bend it

to

get it in.

7

NOTE:

When the write/protect notch

is

covered by tape, the contents

of

the

diskette cannot be altered or added to. That prevents accidental erasing

of

informa-

tion you want to preserve.

If

a diskette comes without a write/protect notch, the

contents of that diskette were not meant

to

be altered.

Blank diskettes may not have a label on them when you purchase them.

With the diskette

in

position, seat

it

properly for use by twisting the door lever

clockwise one-quarter turn until it stops vertically over the slot.

Warning: If

it

doesn't

move easily, stop. You may have put the diskette

in

the wrong way, or incompletely. If

that happens, reposition the diskette until the door lever closes easily.

=

c:::::::::J

OVAL ACCESS

SLOT

WRITE PROTECT

NOTCH

SOMETIMES COVERED WITH TAPE

Figure 3. Inserting a Diskette

DISKETTE

CARE

I.

Don't

touch the exposed parts of a diskette.

That includes the access slot and the center hub (the hole

in

the middle).

2.

Don't

bend a diskette.

They're called floppy diskettes, but they're not supposed to

be

flopped.

3. Keep the diskettes (and disk drive) away from magnets. That includes the electromagnets

in

telephones, televisions, desk lamps, and calculator cords. Keep smoke, moisture, dust, and food off the diskettes. Store diskettes upright in

their paper jackets.

4. Buy diskettes with reinforced hubs. Although the drive usually centers a diskette correctly,

it

would

be

difficult to rescue

data from a diskette recorded with

its

hub off-center. Reinforced hubs make

it

easier

for the drive to center a diskette.

5. Remove a diskette before turning the drive off. If you don't, you might lose part or

all

the data on the diskette.

6. Don't remove a diskette from the drive while the green light

is

glowing.

That light glows when the drive

is

in

use. If you remove the diskette then, you might

lose the information currently being written to the diskette.

8

USING PRE-PROGRAMMED (SOFTWARE) DISKETTES

Your software user's guide should list the procedure for loading the program into

your computer. Nevertheless, we've included the following procedure

as

a general guide.

You'll also use this procedure to load programs or files from your own diskettes. For

purposes

of

demonstration, use the Test/Demo diskette included with the disk drive.

1.

Tum on system.

2. Insert diskette.

3.

If

you are using a VIC 20, Commodore 64, or a Commodore

128

computer in C64

mode, type: LOAD

"HOW

TO USE"

,8

If

you are using a Plus/4 or Commodore

128

in C128 mode, type: DLOAD

"HOW

TO

USE"

4. Press the RETURN key.

5. The following will then appear on the screen:

SEARCHING FOR 0:HOW TO USE LOADING

READY

•

6. Type: RUN

7. Press the RETURN key.

To load a different program or file, simply substitute its name

in

place

of

HOW TO USE inside the quotation marks. NOTE: The HOW TO USE program is the key to the Test/Demo diskette. When you LOAD and RUN it, it provides instructions for using the rest

of

the programs on the diskette. To find out what programs are on your Test/Demo

diskette, refer

to

the section entitled "DIRECTORIES" later in this chapter.

If a program doesn't load or run properly using the above method, it may

be

that it

is a machine language program. But unless you'll be doing advanced programming, you need not know anything about machine language. A program's user's guide should tell you if it

is

written in machine language.

If

it is, or if you are having trouble loading a

particular program, simply add a

,1

(comma and number

1)

at the end

of

the command.

9

IMPORT ANT

NOTE

Throughout this manual, when the format for a command

is

given,

it

will

follow a particular style. Anything that

is

capitalized must bc typcd

in

exactly

as

it

is

shown (these commands are listed

in

capital letters for style purposes,

DO

NOT

use the SHIFT key when entering these commands). Anything

in

lower case

is

more or less a definition

of

what belongs there. Anything

in

brackets

is

optional.

For instance,

in

the format for the HEADER command given on the following

page, the word HEADER, the capital I

in

lid, the capital 0

in

Ddrive#, and the

capital U

in

Udevice# must

all

be

typed

in

as

is

(Ddrive# and Udevice# are

optional).

On the other hand, diskette name tells you that you must enter a name for the

diskette, but it

is

up to you to decide what that name will be. Also, the

id

in

lid

is

left to your discretion,

as

is

the

device#

in

Udevice#. Thc

drive#

in

Ddrive#

is

always 0 on the 1571, but could be 0 or I on a dual disk drive.

Be

aware, however,

that there are certain limits placed on what you can use.

In

each casc, those limits are explained immediately following the format (for instance, the diskette name cannot be more than sixteen characters and the device#

is

usually 8).

Also be sure to type

in

all punctuation exactly where and how

it

is

shown

in

the format.

Finally, press the RETURN key at the

end

of

each command.

HOW TO PREPARE A

NEW

DISKETTE

A diskette needs a pattern of magnetic grooves

in

order for the drive's read/write

head to

find

things on

it.

This pattern

is

not on your diskettes when you buy them, but you

can use the HEADER command or the NEW command

to

add

it

to a diskette. That

is

known

as

formatting the disk. This

is

the command to use with the C

128

in

C I

28

mode or

Plus/4:

HEADER "diskette

name"

,lid, Ddri

ve#

[, U device# J

Where:

"diskette

name"

is

any desired name for the diskette,

up

to

16

characters long (including

spaces).

"id"

can be any two characters

as

long

as

they don't form a BASIC keyword

(such

as

IF or ON) either on their own or with the capital I bcfore them.

"drive#"

is

0 .

"device#"

is

8, unless you have changed

it

as

per instructions

in

Appendix A (the

1571

assumes 8 even if you don't type

it

in).

The command for the C64, VIC 20, or CI28

in

C64 mode

is

this:

OPEN 15,device#,

15,

"NEWdrive#:diskette name,id"

CLOSE

15

The device#,

drive#,

diskette name, and

id

are the same

as

described above.

The OPEN command

is

explained

in

the next chapter. For now, just copy

it

as

is.

10

NOTE TO ADVANCED USERS

If you want to use variables for the diskette name or id, the format

is

as

follows:

C128, Plus/4:

HEADER (A$),J(B$),DO

C64: OPEN

J5,8,15:PRINT#15,"NO:"+A$+B$:CLOSEI5

Where:

A$ contains the diskette name (16 character limit) B$ contains the

id

(2 characters long)

After you format a particular diskette, you can reformat

it

at any time. You can

change

its

name and erase

its

files faster by omitting the

id

number

in

the HEADER

command.

DISKETTE DIRECTORY

A directory

is

a list of the files on a diskette. To load the directory

on

the C

128

or Plus/4, type the word DIRECTORY on a blank line and press the RETURN key or simply press the

F3

key on the C128. That doesn't erase anything

in

memory,

so

you can call up a directory anytime--even from within a program. The C64 directory command, LOAD "$",8

(press RETURN) LIST (press RETURN), does erase what's

in

memory.

If

a directory doesn't all

fit

on the screen,

it

will scroll

up

until

it

reaches the last line. If you want to pause, stop, or slow down the scrolling, refer to your particular computer's user's manual for instructions

as

to

which keys

to

use.

To get an idea

of

what a directory looks like, load the directory from the Test/Demo

diskette.

The 0 on the left-hand side

of

the top line

is

the drive number of the

1571

(on a dual

disk drive it could be 0 or

1). The diskette name

is

next, followed by the diskette

id-both

of which are determined when the diskette

is

formatted.

The

2A

at the end

of

the top line means the

1571

uses Version 2A

of

Commodore's

disk operating system (DOS).

Each of the remaining lines provides three pieces

of

information about the files on the

diskette. At the left end

of

each line is the size

of

the

file

in

blocks

of

254 characters. Four

blocks are equivalent to almost I K of memory inside the computer. The middle

of

the line

contains the name

of

the

file

enclosed

in

quotation marks. All characters within the

quotation marks are part

of

the filename. The right side

of

each line contains a three-letter

abbreviation

of

the

file

type. The types

of

files are described

in

later chapters.

11

TYPES OF FILES

PRG-Program SEQ-Sequential REL-Relative

USR-User DEL-Deleted

(you won't see this type)

Note: Direct Access files, also called Random files,

do

not automatically appear in

the directory. They are covered in Chapter 7.

The bottom line

of

a directory shows how many blocks are available for use. This

number ranges from 664 (in

1541

mode) and 1328 (in

1571

mode) on a newly formatted

diskette

to

0 on one that

is

completely full.

SELECTIVE DIRECTORIES

By altering the directory LOAD command, you can create a kind

of

"sub-directory"

that lists a single selected type

of

file. For example, you could request a list

of

all

sequential data files (Chapter 5), or one

of

all the relative data files (Chapter 6). The

format for this command

is:

LOAD"$0:pattern = filetype",8 (for the C64)

where pattern specifies a particular group

of

files, and filetype

is

the one-letter abbrevia-

tion for the types

of

files listed below:

P

= Program

S

= Sequential

R

= Relative

U

= User

The command for the C128 and Plus/4

is

this: DIRECTORY " pattern = filetype"

Some examples:

LOAD"$0:*

=

R",8

and DIRECTORY"* =

R"

display all relative files.

LOAD"$0:Z*

=

R",8

and DIRECTORY"Z* =

R"

display a sub-directory consist-

ing

of

all relative

files

that start with the letter Z (the asterisk

(*)

is

explained in the

section entitled "Pattern Matching. "

12

PRINTING A DIRECTORY

To get a printout

of

a directory, use the following:

LOAD"$"

,8 OPEN4,4:CMD4:LIST PRINT#4:CLOSE4

PATTERN MATCHING

You can use special pattern-matching characters

to

load a program from a partial

name

or

to provide the selective directories described earlier.

The two characters used in pattern matching are the asterisk (*) and the question

mark (?). They act something like a wild card in a game

of

cards. The difference between the two is that the asterisk makes all characters in and beyond its position wild, while the question mark makes only its own position wild. Here are some examples and their results:

LOAD" A *"

,8

loads the first file on disk that begins with an A, regardless

of

what

follows

DLOAD"SM?TH"

loads the first file that starts with SM, ends with TH, and one

other character between

DIRECTORY"Q*"

loads a directory of files whose names begin with Q

LOAD"*",8

is

a special case. When

an

asterisk

is

used alone

as

a name, it matches

the last

file

used (on the C64 and

Cl28

in C64 mode).

LOAD

"0:*",8

loads the first file on the diskette (C64 and

Cl28

in C64 mode).

DLOAD

"*,,

loads the first

file

on the diskette (Plus/4 and C128

in

Cl28

mode).

SPLAT FILES

One indicator you may occasionally notice on a directory line, after you begin saving

programs and files, is an asterisk appearing just before the

file

type

of a file

that is 0 blocks long. This indicates the file was not properly closed after it was created, and that it should not be relied upon. These

"splat"

files normally need to be erased from the

diskette and rewritten. However,

do

not use the SCRATCH command

to

get rid

of

them.

They can only be safely erased by the VALIDATE or COLLECT commands. One

of

these should normally be used whenever a splat

file

is

noticed on a diskette.

All

of

these

commands are described in the following chapters.

There are two exceptions

to

the above warning: one

is

that VALIDATE and

COLLECT cannot be used on some diskettes that include direct access (random)

files

(Chapter 7). The other

is

that

if

the information

in

the splat

file

was crucial and can't be

replaced, there is a way to rescue whatever part

of

the

file

was properly written. This

option is described in the next chapter.

13

--

CHAPTER 2

BASIC

2.0

COMMANDS

This chapter describes the disk commands used with the VIC 20, Commodore 64 or

the Commodore

128

computer in C64 mode. These are Basic 2.0 commands.

You send command data to the drive through something called the command

channel. The first step is to open the channel with the following command:

OPENI5,8,15

The first

15

is a file

number or channel number. Although

it

could be any number

from 1 to 255, we'll use

15

because it is used

to

match

the

secondary address

of

15, which

is

the address

of

the command channel. The middle number is the primary address, better

known as the device number. It

is

usually 8, unless you change

it

(see Appendix A).

Once the channel has been opened, use the

PRINT#

command

to

send information

to

the disk drive and the

INPUT#

command

to

receive information from the drive. You

must close the channel with the CLOSE15 command.

The following examples show the use

of

the command channel

to

NEW an unformat-

ted disk:

OPENI5,8,15

PRINT#15,"NEWdrive#:diskname,id"

CLOSE15

You can combine the first two statements and abbreviate the NEW command like

this:

OPENI5,8, 15,

"Ndrive#

:diskname,id"

If

the command channel

is

already open, you must use the following format (trying

to

open a channel that is already open results in a

"FILE

OPEN" error):

PRINT#15 , "Ndrive#:diskname,id',

ERROR CHECKING

In Basic 2.0, when the green drive light flashes, you must write a small program

to find out what the error is. This causes you to lose any program variables already in memory. The following

is

the error check program:

10

OPENI5,8,15 20INPUT#15,EN,EM$,ET,ES 30 PRINT EN, EM$,ET,ES 40 CLOSE15

This little program reads the error channel into four BASIC variables (described

below), and prints the results on the screen. A message

is

displayed whether there

is

an

14

error or not, but if there was

an

error, the program clears it from disk memory and turns

off the error light on the disk drive.

Once the message

is

on the screen, you can look it

up

in

Appendix B

to

see what it

means, and what to

do

about it.

For those

of

you who are writing programs, the following

is

a small error-checking

subroutine you can include in your programs:

59980 REM READ ERROR CHANNEL 59990INPUT#15,EN,EM$,ET,ES 60000 IF

EN>1

THEN PRINT EN,EM$,ET,ES:STOP

60010 RETURN

This assumes

file

15

was opened earlier

in

the program, and that

it

will

be

closed at

the end

of

the program.

The subroutine reads the error channel and puts the results into the named varia-

bles-EN

(Error Number), EM$ (Error Message), ET (Error Track), and

ES

(Error

Sector).

Of

the four, only EM$ has

to

be a string. You could choose other variable names,

although these have become traditional for this use.

Two error numbers are harmless---O means everything

is

OK, and 1 tells how many

files were erased by a SCRATCH command (described later

in

this chapter). If

the

error

status

is

anything else, line 60000 prints the error message and halts the program.

Because this

is

a subroutine, you access

it

with the BASIC GOSUB command, either in immediate mode or from a program. The RETURN statement in line 60010 will jump back

to

immediate mode or the next statement

in

your program, whichever

is

appropriate.

BASIC

HINTS

Hint

#1:

It

is

best

to

open

file

15

once at the very start

of

a program, and only close it at

the end

ofthe

program, after

all

other files have already been closed. By opening it once at

the start, the file is open whenever needed for disk commands elsewhere

in

the

program.

Hint

#2:

If

BASIC halts with an error when you have files open, BASIC aborts them

without closing them properly on the disk. To close them properly

on

the disk, you must

type:

CLOSE 15:0PEN

15,8,15,"I":CLOSE

15

This opens the command channel and immediately closes it, along with

all

other disk

files. Failure to close a disk

file

properly both

in

BASIC and

on

the

disk may result

in

losing the entire file.

Hint

#3:

One disk error message

is

not always an error. Error 73,

"CBM

DOS 3.0

1571" will appear if you read the disk error channel before sending any disk commands

when you tum on your computer. This

is

a handy way

to

check which version

of

DOS

you

are using. However, if this message appears later, after other disk commands,

it

means

there

is

a mismatch between the DOS used

to

format your diskette and the

DOS

in

your

drive. DOS

is

Disk Operating System.

15

Hint

#4:

To reset drive, type: OPEN 15,S,15,"UJ":CLOSE 15. This also applies to

sending a VI

+

or

a VI.

SAVE

Vse the SAVE command

to

preserve a program or

file

on a diskette for later use.

Before you can SAVE

to

diskette, the diskette must be formatted,

as

described

earlier.

FORMAT FOR THE SAVE COMMAND

SAVE

"drive

#:file name" ,device #

where "file name" is any string expression

of

up to

16

characters, preceded by the drive

number and a colon, and followed by the device number

of

the disk, normally

S.

However, the SAVE command will not work

in

copying programs that are not in the

BASIC text area, such as

"DOS

5.1"

for the C64. To copy it and similar machine-

language programs, you will need a machine-language monitor program.

FORMAT FOR A MONITOR SAVE

.S "drive #:file name" ,device # ,starting address,ending address

+ 1

where "drive

#:"

is

the drive number, 0 on the 1571; "file name"

is

any valid

file

name

up to

14

characters long (leaving two for the drive number and colon); "device

#"

is a

two digit device number, normally

OS

(the leading 0

is

required); and the addresses

to

be

saved are given in Hexadecimal but without a leading dollar sign

($). Note the ending

address listed must be one location beyond the last location

to

be saved.

EXAMPLE:

Here

is

the required syntax

to

SAVE a copy of

"DOS

5.1"

.S "O:DOS

5.1"

,OS,CCOO,DOOO

SAVE WITH REPLACE OPTION

If a file already exists, it can't be saved again with the same name because the disk

drive only allows one copy

of

any given

file

name per diskette. It

is

possible to get around this problem using the RENAME and SCRATCH commands described later. However, if all you wish

to

do

is

replace a program or data

file

with a revised version, another

command is more convenient. Known

as

SAVE-WITH-REPLACE, or @SAVE, this

option tells the disk drive to replace any

file

it

finds

in

the diskette directory with the same

name, substituting the new

file

for the old version.

16

FORMAT FOR SAVE WITH REPLACE:

SAVE"@Drive #:file

name",

device #

where all the parameters are

as

usual except for adding a leading

"at"

sign (@.) The

"drive

#:"

is required here.

EXAMPLE:

SA VE"@O:REVISED PROGRAM"

,8

The actual procedure

is

that the new version

is

saved completely, then the old version

is

erased. Because it works this way, there is little danger a disaster such

as

having the power going off midway through the process would destroy both the old and new copies of

the file. Nothing happens

to

the old copy until after the new copy is saved properly.

Caution--do not use @SAVE on

an

almost-full diskette. Only use it when you have

enough room on the diskette to hold a second complete copy

of

the program being

replaced. Due

to

the way @SAVE works, both the old and new versions

of

the

file

are

on

disk simultaneously at one point,

as

a way

of

safeguarding against loss

of

the program.

If

there

is

not enough room left

on

diskette

to

hold that second copy, only

as

much

of

the

new version will be saved

as

there

is

still room for. After the command executes, a look at

the directory will show the new version

is

present, but doesn't occupy enough blocks

to match the copy in memory. Unfortunately, the VERIFY command (see below) will not detect this problem, because whatever was saved will have been saved properly.

VERIFY

Although not

as

necessary with a disk drive

as

with a cassette, BASIC's VERIFY

command can be used to make doubly certain that a program

file

was properly saved

to disk. It works much like the LOAD command, except that it only compares each character in the program against the equivalent character in the computer's memory, instead

of

actually being copied into memory.

If

the disk copy

of

the program differs even a tiny bit from the copy in memory, "VERIFY ERROR" will be displayed, to tell you that the copies differ. This doesn't mean either copy is bad, but if they were supposed to

be

identical, there

is

a problem.

Naturally, there's

no

point in trying to VERIFY a disk copy

of

a program after the

original is no longer in memory. With nothing

to

compare to,

an

apparent error will

always be announced, even though the disk copy is always and automatically verified

as

it

is

written to the diskette.

FORMAT FOR THE VERIFY COMMAND:

VERIFY "drive#:pattern" ,device#,relocate

flag

where

"drive#:"

is

an optional drive number, "pattern" is any string expression that

evaluates

to a file

name, with or without pattern-matching characters, and

"device#"

is

the disk device number, normally 8.

If

the relocate

flag

is

present and equals

1,

the

file

will be verified where originally saved, rather than relocated into the BASIC text area.

17

A useful alternate form

of

the command

is:

VERIFY"*"

,device #

It verifies the last files used without having

to

type its name or drive number. However, it

won't work properly after SAVE-WITH-REPLACE, because the last file used was the

one deleted, and the drive will try

to

compare the deleted

file

to

the program in memory. No harm will result, but "VERIFY ERROR" will always be announced. To use VERIFY after @SAVE, include at least part

of

the

file

name that

is

to be verified in the pattern.

One other note about

VERIFY-when

you VERIFY a relocated BASIC file,

an

error

will nearly always be announced, due

to

changes in the link pointers

of

BASIC programs

made during relocation.

It

is best

to

VERIFY files saved from the same type

of

machine, and identical memory size. For example, a BASIC program saved from a Plus/4 can't be verified easily with a C64, even when the program would work

fine

on both machines.

This shouldn't matter,

as

the only time you'll be verifying files on machines other than the

one which wrote them

is

when you are comparing two disk files to see if they are the same. This is done by loading one and verifying against the other, and can only be done on the same machine and memory size

as

the one on which the files were first created.

SCRATCH

The SCRATCH command allows you

to

erase unwanted files and free the space they

occupied for use

by

other files. It can be used

to

erase either a single

file

or several files at

once via pattern-matching.

FORMAT

FOR

THE

SCRATCH

COMMAND:

PRINT#15, "SCRATCH(I):pattern"

or abbreviate it

as:

PRINT # 15, "S(I):pattern"

"pattern"

can be any

file

name or combination

of

characters and wild-card characters.

As

usual, it

is

assumed the command channel has already been opened

as

file

15.

Although

not absolutely necessary, it

is

best

to

include the drive number

in

SCRATCH commands.

If

you check the error channel after a SCRATCH command, the value for ET (error track) will tell you how many files were scratched. For example, if your diskette contains program files named

"TEST,"

"TRAIN,"

"TRUCK,"

and

"TAIL,"

you may SCRATCH all four, along with any other files beginning with the letter' 'T," by using the command:

PRINT#15, 'SO:T*'

Then, to prove they are gone, you can type:

GOSUB 59990

18

to call the error checking subroutine given earlier

in

this chapter. If the four listed were the

only files beginning with

"T",

you will see:

01

,FILES SCRATCHED,04,00

READY.

The

"04"

tells you 4 files were scratched.

MORE ABOUT SCRATCH

SCRATCH is a powerful command and should be used with caution

to

be sure you

delete only the files you really want erased. When using

it

with a pattern,

we

suggest you

first use the same pattern

in

a DIRECTORY command, to be sure exactly which files will

be deleted. That way you'll have no unpleasant surprises when you use the same pattern

in

the SCRATCH command.

Recovering from a SCRATCH

If

you accidentally SCRATCH a

file

you shouldn't have, there

is

still a chance of

saving it. Like BASIC's NEW command, SCRATCH doesn't really wipe out a

file

itself;

it merely clears the pointers to

it

in

the diskette directory. There may be an "Unscratch"

program on your Test/Demo diskette.

NOTE:

If you accidentally SCRATCH a

file

within the DOS Shell (see Chapter 4),

you can unscratch it with the Shell's RESTORE FILES function.

More about Splats

Never scratch a splat file. These are files that show up

in

a directory listing with an

asterisk

(*) just before the

file

type for an entry. The asterisk (or splat) means that

file

was

never properly closed, and thus there

is

no valid chain

of

sector links for the Scratch

command to follow

in

erasing the file.

If you SCRATCH such a file, odds are you will improperly free up sectors that are

still needed by other programs or files and cause permanent damage to those later when

you add more files to the diskette.

If

you

find

a splat file, or if you discover too late that you have scratched such a file, immediately validate the diskette using the VALIDATE command described later

in

this chapter. If you have added any files to the diskette since

scratching the splat file, it

is

best to immediately copy the entire diskette onto another fresh diskette, but do this with a copy program rather than with a backup program. Otherwise, the same problem will be recreated on the new diskette. When the new copy is done, compare the number

of

blocks free

in

its directory to the number free on the original diskette. If the numbers match, no damage has been done. If not, very likely at least one file on the diskette has been corrupted, and all should be checked immediately.

19

Locked Files

Occasionally, a diskette will contain a locked

file;

one which cannot be erased with

the SCRATCH command. Such files may be recognized by the

"<"

character which

immediately follows the

file

type

in

their directory entry.

If

you wish

to

erase a locked

file, you will have

to

use a disk monitor

to

clear bit 6

of

the file-type byte

in

the directory

entry on the diskette. Conversely,

to

lock a file, you would set bit 6

of

the same byte.

RENAME

The RENAME command allows you

to

alter the name of a program or other

file

in the

diskette directory. Since only the directory

is

affected, RENAME works.very quickly.

FORMAT FOR RENAME COMMAND:

PRINT#15, "RENAME0:new name = old name"

or it may be abbreviated as:

PRINT#15,"R0:new

name=old

name"

where

"new

name"

is

the name you want the

file

to have, and

"old

name"

is

the name

it

has now.

"new

name" may be any valid

file

name,

up

to

16

characters in length.

It

is

assumed you have already opened

file

15

to

the command channel.

One

caution-be

sure the

file

you are renaming has been properly closed before you

rename it.

EXAMPLES:

Just before saving a new copy

of

a "calendar" program, you might type:

PRINT#

15,"R0:CALENDAR/BACKUP = CALENDAR"

Or

to

move a program called

"BOOT,"

currently the first program on a diskette

to

someplace else in the directory, you might type:

PRINT#15,

"R0:TEMP=

BOOT"

followed

by

a COPY command (described later),.which turns

"TEMP"

into a new copy

of

"BOOT,"

and finishing with a SCRATCH command

to

get rid

of

the original copy

of

"BOOT.

"

20

RENAMING AND SCRATCHING TROUBLESOME FILES (ADVANCED USERS)

Eventually, you may run across a file which has an odd filename, such as a comma

by itself

(" , ")

or one that includes a Shifted Space (a Shifted Space looks the same

as

a

regular space, but

if

a file with a space in its name won't load properly and all else

is correct, it's probably a Shifted Space). Or perhaps you will find one that includes nonprinting characters. Any

of

these can be troublesome. Comma files, for instance, are

an exception

to

the rule that no two files can have the same name. Since it shouldn't be

possible to make a file whose name

is

only a comma, the disk never expects you

to

do

it

again.

Files with a Shifted Space in their name can also be troublesome, because the disk

interprets the Shifted Space as signaling the end

of

the

file

name, and prints whatever

follows after the quotation mark that marks the end

of

a name in the directory. This

technique can be useful by allowing you

to

have a long file name, and making the disk

recognize a small part

of

it as being the same as the whole thing without using pattern-

matching characters.

In

any case,

if

you have a troublesome filename, you can use the CHR$O function to specify troublesome characters without typing them directly. This may allow you to build them into a RENAME command.

If

this fails, you may also use the pattern-matching

characters in a SCRATCH command. This gives you a way

to

specify the name without

using the troublesome characters at all, but also means loss

of

your file.

For example, if you have managed

to

create a file named

""MOVIES",

with an

extra quotation mark at the front

ofthe

file

name, you can rename it

to

"MOVIES"

using

the CHR$O equivalent

of

a quotation mark in the RENAME command:

PRINT#15, "R0:MOVIES

="

+CHR$(34) +

"MOVIES"

The CHR$(34) forces a quotation mark into the command string without upsetting BASIC. The procedure for a file name that includes a Shifted Space

is

similar, but uses

CHR$(160).

In

cases where even this doesn't work, for example,

if

your diskette contains a

comma file, (one

named"

,")

you can get rid

of

it

this

way:

PRINT#15,

"S0:?"

This example deletes all files with one character names. Depending on the exact problem, you may have

to

be very creative in choosing pattern-matching characters that will affect only the desired file, and may have to rename other files first

to

keep them from being scratched.

In

some cases, it may be easier

to

copy desired files

to

a different diskette and leave

the troublesome files behind.

COpy

The COPY command allows you to make a spare copy of any program or

file

on a

diskette. On a single drive like the 1571, the copy must be on the same diskette, which

means it must be given a different name from the file copied. It's also used

to

combine up

21

to

four sequential data files (linking the files one

to

another, end

to

end

in

a chain). Files

are linked in the order

in

which they appear

in

the command. The source files and other

files on the diskette are not changed. Files must be closed before they are copied or linked.

FORMAT FOR THE COPY COMMAND

PRINT#IS,"COPYdrive

#:new

file=old

file"

EXAMPLES:

PRINT#lS,'

'COPY0:BACKUP= ORIGINAL"

or abbreviated as

PRINT#1 S,"Cdrive

#:new

file=old

file"

PRINT#IS,

"C0:BACKUP = ORIGINAL"

where

"drive

#"

is the drive number

"new

file"

is

the copy and

"old

file"

is

the

original.

FORMAT FOR THE COMBINE OPTION

PRINT#lS,

"Cdrive

#:new

file = file

1 ,file 2,file 3,

file

4"

where

"drive

#"

is

always 0,

NOTE: The length

of

a command string (command and filenames)

is

limited to

41

characters.

EXAMPLES:

After renaming a

file

named

"BOOT"

to

"TEMP"

in the last section's example,

you can use the

COpy

command

to

make a spare copy of the program elsewhere

on

the

diskette, under the original name:

PRINT#IS,

"C0:BOOT =

TEMP"

After creating several small sequential files that

fit

easily

in

memory along with a

program we are using, you can use the concatenate option to combine them

in

a master

file, even if the result

is

too big

to

fit

in

memory. (Be sure it will

fit

in remaining space on

the

diskette-it

will be

as

big

as

the sum

of

the sizes of the files in it.)

PRINT#IS,

"C0:A-Z = A-G,H-M,N-Z"

22

Commodore 1570, 1571 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual