Commodore CBM 2040, CBM 3040, CBM 4040, CBM 8050 User Manual

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User's Manua for

CBM Dual Drive

Floppys

Model 2040-Model 4040

Model 3040-Model 8050

Appropriate for use with:

Commodore Computers

• Series 2001 (CBM-PET)

• Series 3000 (CBM)

• Series 4000 (PET)

• Series 8000 (CBIVI)

Part Number 320899

October 1980

c o m m o d o r e

^ Table of Contents

Chapter 1

Chapter 2

Chapter 3

Introduction

General Information

Description

Front Panel

Back Panel

Interior Configuration

The Diskette

Specifications

Care Of The 2040,3040,4040 and 8050

Care Of The Diskettes

Unpacking The Disk Drive

Preparing To Use Your Disk Drive

Connecting The Disk Drive To The Computer

Performing The Power-On Test

Inserting The Diskette Into The 8050 liisi!fliii|j Till! IJiiiktiUe liilu Tlie HO-IO, ijO-lO uml <10'1()..

Iit

The 4040 and 8050 Performance Test 14

The 2040 and 3040 Performance Test 17

Learning How To Use Your Floppy Disk Drive

The Block Availability Map (BAM)

The Disk Operating System (DOS)

Disk Maintenance Commands

NEW

HEADER (BASIC 4.0 Direct Command)

Initialization (2040 and 3040)

Initialization (4040)

Initialization (8050)

The Directory

LOAD$ 26

DIRECTORY (BASIC 4.0 Dkect Command) .

Printing The Dhrectory 27

Page

9 in

Chapter 4

Chapter 5

Chapter 6

VALIDATE 28

COLLECT (BASIC 4.0 Direct Command)....

DUPLICATE

BACKUP (BASIC 4.0 Direct Command)

COPY

COPY (BASIC 4.0 Direct Command)

RENAME

CONCAT (BASIC 4.0 Direct Command) 31

32 RENAME (BASIC 4.0 Direct Command)

SCRATCH 32

SCRATCH (BASIC 4.0 Direct Command)....

BASIC Commands For Data Handling 35

BASIC Commands Associated with Floppy Disk Drives 35

SAVE and DSAVE (Writing a Program to a Diskette)...

LOAD and DLOAD (Reading a Program from a

Diskette) 36

VERIFY

OPEN

DOPEN

DCLOSE

Closing The Command Channel

Closing The Data Channel

PRINT#

INPUT#

GET#

RECORD#

Quickload Feature (BASIC 4.0)

Moving a Tape Program to Disk

Advanced Disk Programming

Commodore Disk Operating System (DOS)

Disk Utility Command Set

BLOCK-READ

BLOCK-WRITE

BLOCK-EXECUTE

BUFFER-POINTER

BLOCK-ALLOCATE

MEMORY

MEMORY-WRITE

MEMORY-READ

MEMORY-EXECUTE

USER

8050 Disk Zones

[ * 49

50 ^

51 ~

Advanced File Handling

Special Open and Close Statements For Direct Access'

Random Access Example

To Create A File

To Add A Record

To See A Record

To Change A Record

Getting The Directory of Listings

Directory Format

Sequential Format

Program File Format

Relative File Format

User's Quick Reference —Disk Commands

* ] ]

.!!!!!!...!!!!!!. 70

Figure

Table

Ending The Program

Relative Files 4040,8050

Creating A Relative File

Expanding A Relative File

Accessing A Relative File

Chapter 7

Chapter 8

Simplifying The Use of Commodore Disk-Related Commands

Loading The DOS Support Program

Using The DOS Support Symbols: > and @

Loading A Program With The /

Loading And Running A Program With Up Arrow

Special DOS Support Information

Error Messages —Pattern Matching File Names —Disk Commands

Requesting Error Messages: Commodore Disk Drives

Summary Of CBM Floppy Error Messages

Description of DOS Error Messages

Pattern Matching

User's Quick Reference: Disk Commands

Random 1.00 Program Listing Chapter 9

Chapter 10 Index

List of Illustrations

Title

Models 2040, 3040,4040,8050: Rear View

Floppy Disk Hookup

Position For Diskette Insertion

2040,3040,4040 Format: Expanded View of A Single Sector

8050 Format: Expanded View of A Single Sector

Page

List of Tables

Title

Chapter

INTRODUCTION

The disk-oriented Commodore Computer System was designed around the central concept of providing you, the user, with large file-handling capabilities supported by BASIC pro gramming commands and further simplified by DOS Support command abbreviations.

Read the Table of Contents and become acquainted with the broad scope of material covered in this manual. It has been designed to assist you in pursuing an educational pro gram by utilizing the computer asan adjunct to the learning process. That is, once the disk drive is properly interfaced to a Commodore Computer, YOU become as important an ele ment of the system as the hardware. Your importance, however, is measured in direct rela tionship to how well you understand how to effectively utilize the hardware arid software.

That's why it is best to think of your computer and disk drive as only part of a system.

Grasping and understanding the concept that each individual component acts and reacts to signals and commands from other devices in the system will greatly accelerate your funda mental grasp of how to operate, control, and master the system. This basic concept forms the basis of this manual: teaching you how to gain mastery of the system so that it will perform as desired. That is the primary reason this manual is laid out in a building block fashion: it permits you to advance as fast as you desire.

The first chapters discuss basic hardware features and permit you, right from the start, to become familiar with the disk drive by doing the performance tests which comprise the first essential "hands on" experience. Then, by actually using your particular disk drive and learning to carefully follow instructions, you can gain confidence in order to proceed to more comprehensive subjects.

By the time you begin Chapter 3—Learning How To Use Your Floppy Disk Drive-you will have already used some portions of the DOS Support system which is not fully described until Chapter 7. The reason for this procedure lies within the purpose of DOS Support: simplifying commands. It is actually easier to instruct a new user by using the simplified command structure of DOS Support than attempting to explain the entire command hier archy at an early stage. This concept of providing you with enough essential information to complete a task, a step-by-step description of the task, and meaningful examples is a feature of this manual which will provide you with sufficient incentive to actually complete the task.

The manner in which this manual is laid out encourages the concept of learning by doing.

Difficult concepts and procedures have been broken down into steps that walk the user through examples which provide ample opportunity to experiment later by returning to each command description. When possible, the command format has been included with the command description and, as an additional aid, a User*s Quick Reference has been placed in

Chapter 8 for easy access if problems persist.

Error messages are also presented in Chapter 8 where they can be quickly referenced, if needed. The Error Message discussions have been expanded to include:

• How to request error messages.

• Error message summary.

• Detailed error message descriptions.

For those users who have been reluctant to attempt disk programming because of the pre sumed degree of difficulty, note that the entire disk command hierarchy is structured in this manual from least difficult to more complex:

• Commands for file manipulation and maintenance

• Commands for data handling

• Advanced programming

• Advanced hie handling

• Simplified commands

Users who have attained some degree of programming skills may desire to begin with the advanced subjects such as random access or relative files while others may be content with just following the manual's format. In either case, this manual has been laid out to provide the user with essential information in a logical sequence. Follow the examples, attempt the step-by-step procedures, and learn by doing.

GENERAL INFORMATION

With the purchase of your Commodore Dual Drive Floppy Disk you have greatly enhanced the computing power of your Commodore system. To get the most out of your system you should study your computer's user guide, and if necessary the BASIC manuals listed in

Table 1. You will benefit most if you first read through this entire manual, taking note of those features that relate to your particular floppy as well as those which are common to all

CBM Floppys.

The information presented in this manual is extensive and may, in some cases, present in formation that is currently beyond your particular level of expertise. However, by carefully and thoughtfully studying its contents you will gain the confidence necessary to progres sively upgrade your programming skills and expertise.

This manual presents discussions, descriptions, practices and procedures relating to the use and operation of all Commodore 5-1/4-inch Dual Floppy Disk Drives.

Four models are discussed:

Model 2040 (DOS 1)

Model 3040 (DOS 1)

Model 4040 (D0S2)

Model 8050 (DOS 2.5)

The floppys are operationally compatible with the following Commodore Computers.

1. Series 2001 —16K and 32K —Operating With BASIC Version 3.0

2. Series 2001 —PET 8K — Upgraded to BASIC Version 3.0

3. Series 3000 —16K and 32K —Operating With BASIC Version 3.0

4. Series 4000 - PET 8K, 16K, and 32K - Operating With BASIC Version 4.0

5. Series 8000 —32K —Operating With BASIC Version 4.0

For ease of reference, the Models 2040, 3040,4040, and 8050 Dual Drive Floppy

Disks will be referred to in this manual as "the 2040", "the 3040", "the 4040", and "the 8050", respectively. All descriptions and discussions are common unless noted otherwise.

DESCRIPTION

All CBM Floppys described in this manual are dual-drive diskette storage devices. Their individual primary components consist of read/write controls, drive motor electronics, two drive mechanisms, two read/write heads, and track positioning mechanisms. All disk drives discussed in this manual conform to IEEE-488 interface requirements. Because each device is an "intelligent" peripheral, their operation requires no space in the computer's memory.

This means you have just as much computer memory available to you as when you do not have the disks attached.

Front Panel

The front panel of the respective disk drive consists of an identification panel across the top; slots in which to insert two diskettes; and doors to close after inserting the diskettes. When the door is closed, the diskette is clamped onto the diskette spindle hub. Also on the front panel are three LED indicator lights. The one on the right is called the Drive 0 Active Indi cator, and lights when drive 0 is active. The LED on the left does the same for drive 1. On the 8050, the LED in the middle is a two-color power/error indicator. It is normally green, indicating power ON but flashes red whenever a disk error occurs. On the 2040, 3040, and

4040 the middle LED is activated if power is applied or removed, and whenever an error occurs.

. Back Panel

The back of each disk drive contains an IEEE-488 interface connector. Near the panel's lower edge is the power ON/OFF switch. There is also a "slow blow"i^fuse, and the AC power cord.

Table 1. Suggested Reading List

Pet/CBM Personal Computer Guide.

C. S. Donahue and J. K. Enger, Osborne/McGraw-Hill, 630 Bancroft Way,

Berkeley, CA 94710

Hands-On Basic with a Pet.

H. D. Peckham, McGraw-Hill 1979

Entering BASIC.

J. Sack and J. Meadows, Science Research Associates, 1973

BASIC: A Computer Programming Language.

C. Pegels, 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, Peoples Computer Co., 1010 Doyle (P.O. Box

3100), Menlo Park, CA 94025,1973

A Guided Tour of Computer Programming in BASIC.

T. Dwyer, Houghton Mifflin Co., 1973

Programing Time Shared Computer in BASIC.

Eugene H. Bamett, Wiley-Interscience, L/C 72-175789

Programming Language #2.

Digital Equipment Corp., Maynard, MA 01754

101 BASIC Computer Games.

Software Distribution Center, Digital Equipment Corp., Maynard, MA 01754

What do To After You Hit Return.

Peoples Computer Co., 1010 Doyle (P.O. Box 3100),Menlo Park, CA 94025

Basic BASIC.

James S. Coan, Hayden Book Co., Rochelle Park, NJ

WORKBOOKS 1-5.

T.I.S., P.O. Box 921, Los Alamos, NM 87544

Programming the 6502.

R. Zaks, Sybex, 1978

24 Tested, Ready-to-Run Game Programs in Basic.

K. Tracton, Tab Books, 1978

Some Basic Programs.

M. Borchers and R. Poole, Osborne & Assoc. Inc., 1978

Basic Programming for Business.

I. H. Fotknei, Prentice-Hall, 1977

The Channel Data Book.

B. Lewis, 5960 Mandarin Ave., Goleta, CA 93017,1978

PET and the IEEE 488 Bus (GPIP).

Osbome/McGraw-Hill, 630 Bancroft Way, Berkeley, CA 94710

Interior Configuration

The interior of your floppy containstwo disk drives. All the logic for the disk drive is con tained within the unit. Themechanical devices are, for the most part, located beneath the disk spindles.

The Diskette

The diskette (also known as a minifloppy, floppy diskette, minidiskette, etc.) is similar to the standard flexible disk. There are several reputable manufacturers of the 5 1/4-inch diskettes. You should make sure that you buy diskettes for SOFT SECTORED FORMAT.

Your Commodore dealer can supply your needs.

Specifications

Table 2 presents the specifications for the 8050, Table 3 the specifications for the 2040 and

3040, and Table 4 the 4040.

PIGGYBACK

CONNECTION

{IEEE PLUG )

ON/OFF

SWITCH

Figure 1 — Models 2040, 3040, 4040, 8050: Rear View

^ I

Table 2.Specifications: Model 8050 Dual Drive Floppy Disk

STORAGE:

Total capacity

Sequential

Relative

Directory entries

Sectors per track

Bytes per sector

Tracks

Blocks

533248 bytes per diskette

521208 bytes per diskette

464312 to 517398 bytes per diskette depending upon file size.

182880 bytes per file

65535 records per file

224 per diskette

23 to 29

256

2083

IC's:

Controller

6502

6530

6522

Interface

6502

6532(2)

6564 (2)

Shared

6114 (8)

PHYSICAL:

Material

Dimensions

Height

Width

Depth

ELECTRICAL:

Power requirements

Voltage

Frequency

Power

MEDIA:

Diskettes microprocessor

I/O, RAM, ROM

I/O, interval timers microprocessor

I/O, RAM, interval timers

ROM

4xlK RAM

18 ga. steel

6.5"

15.0"

14.35"

100,117, 220, or 240 VAC

50 or 60 Hertz

50 watts

Standard mini 5 1/4", single sided, single density

o;|

i

-1} >'1'

Table 3. Specifications: Models 2040/3040 Dual Drive Floppy Disk

STORAGE:

Total capacity

Sequential

Random

Directory entries

Sectors per track

Bytes per sector

Tracks

Blocks

176640 bytes per diskette

170180 bytes per diskette

170850 bytes per diskette

152 per diskette

17 to 21

256

690

IC's:

Controller

6504

6530

6522

Interface

6502

6532 (2)

6332(2)

Shared

6114 (8)

PHYSICAL: microprocessor

I/O, RAM, ROM

I/O, interval timers microprocessor

I/O, RAM, interval timers

ROM

4xlK RAM

18 ga. steel Material

Dimensions

Height

Width

Depth

ELECTRICAL:

Power requirements (2040)

Voltage

Frequency

Power

Power requirements (3040)

Voltage

Frequency

Power

MEDIA:

Diskettes

6.5"

15.0"

14.35"

120 VAC

60 Hertz

50 Watts

100, 220, or 240 VAC

60 Hertz

50 Watts

Standard mini 5 1/4", singlesided, single density

CSsi.

Table 4, Specifications: Model 4040 Dual Drive Floppy Disk

STORAGE:

Total capacity

Sequential

Relative

Directory entries

Sectors per track

Bytes per sector

Tracks

Blocks

174848 bytes per diskette

168656 bytes per diskette

167132 bytes per diskette

65535 records per file

144 per diskette

17 to 21

256

683

IC's:

Controller

6504

6530

6522

Interface

6502

6532(2)

6332(2)

Shared

6114(8)

PHYSICAL: microprocessor

I/O, RAM, ROM

I/O, interval timers microprocessor

I/O, RAM, interval timers

ROM

4xlK RAM

Material

Dimensions

Height

Width

Depth

18 ga. steel

6.5"

15.0"

14.35"

ELECTRICAL:

Power requirements (4040) USA (domestic)

Voltage 120 VAC

Frequency

Power

60 Hertz

50 Watts

Power requirements (4040) (international)

Voltage 100,220, or 240 VAC

Frequency

Power

60 Hertz

50 Watts

MEDIA:

Diskettes Standard mini 5 1/4", single sided, single density

CARE OF THE 2040, 3040, 4040 AND 8050

The disk drive should be placed on a fiat surface free of vibration. It is important that dust particles be kept at a minimum since a particle buildup will interfere with optimum opera tion. If you should experience a hardware failure contact your Commodore dealer. Any attempt to correct the problem yourself could result in voiding 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 envelope whenever it is removed from the drive.

2. Keep the diskettes away from magnetic fields. Exposure to a magnetic field can distort the data.

3. Never leave a diskette on top of your computer or disk drive.

4. Do not write on the plastic jacket with a lead pencil or ball-point pen. Use a felt tip pen or fill out the label before attaching it to the jacket.

5. Do not expose diskettes to heat or sunlight.

6. Do not touch or attempt to clean the diskette surface. Abrasions will cause loss of stored data.

7. Before applying power to the 2040,3040, or 4040 open the drive doors and remove diskettes.

UNPACKING THE DISK DRIVE

Before unpacking the disk drive, inspect the shipping carton for signs of external damage. If the carton is damaged, be especially careful when inspecting its contents. Carefully remove all packing material and the contents of the carton. DO NOT discard any packing material until you have made sure you have located all the contents of the carton! The carton should contain:

1. Commodore Dual Floppy Disk Drive

2. User Manual, Number 320899

3. One of the following TEST/DEMO diskettes: a. 2040/3040/4040 TEST/DEMO diskette, P/N 4040037 b. 8050 TEST/DEMO diskette, P/N 8050050

If any items are missing, please contact your Commodore dealer immediately.

NOTES

Chapter ^

PREPARING TO USE

YOUR DISK DRIVE

Before startingto useyour disk drive, make sure it is in good working condition.Thisin

cludes properly connecting it to your computer, giving it a power-on and initial checkout test, andfinally the performance test using the appropriate TEST/DEMO diskette.

CONNECTING THE DISK DRIVE TO THE COMPUTER

One of two connector cables are required to interface the floppy to the computer. These cables can be supplied by your Commodore dealer.

1. PET-to-IEEE cable, P/N 320101

Use this cable if the disk drive is to be the only (or first) IEEE device connected to your computer.

2. lEEE-to-IEEE cable, P/N 905080

Use this cable if your diskdrive is to be connected ("daisy-chained") to another peri pheral device such as the Commodore Model 2022, or any other suitable interfaced printer.

NOTE: The disk driveshould be the first peripheralattached to the computer if other de vices are to be "daisy-chained".

Follow these steps to connect the disk drive to your computer:

STEP 1: Turn power OFF to the computer..

STEP 2: Place the disk drive in a convenient 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 PET-to-IEEEcable between the IEEE-488 interface connector on the computer and the connector on the disk drive. If additional IflEE devices are to be connected, the lEEE-to-IEEE cable(s) must be used.

STEP 4: Connect the disk drive power cable to an AC outlet. DO NOT turn on power at this time.

Floppy Disk

CBM Computer i W

PET-to-IEEE Cable

(P/N 320101) lEEE-to-IEEE Cable

(P/N 905080)

Printer

Figure 2 —Floppy Disk Hookup

PERFORMING THE POWER-ON TEST

You are now ready to proceed witli the poweron part of the checkout:

STEa-1: Open both disk drive doors. Ensure that no diskettes are present in either drive.

STEP 2: power ON to the COMPUTER and verify that it is working properly.

INSERTING THE DISKETTE INTO THE 8050

STEP 1: Insert the diskette into the slot designated "Drive 0" and with the write protect tab oriented to the left.

STEP 2: Once the diskette is in the slot, push gently on the diskette until you hear a dis* tinct "clock". The diskette is now properly positioned in the drive.

STEP 3: Press DOWN firmly on the spring-loaded door of the drive to lower the diskette into the correct position. It is important to press firmly on the door in a smooth motion to avoid damaging the diskette.

STEP 4: To remove the diskette, press DOWN firmly on the spring-loaded door. This will release the spring and raise the diskette. Wlien the diskette is level with the open ing, press UP on the door. This will release the diskette and push it out toward the front of the drive. The diskette is now free to be removed from the drive.

STEP 5: DO NOT ATTEMPT TO CLOSE THE DOOR WITHOUT A DISKETTE IN

PLACE. The door is locked open by a mechanical interlock mechanism associated with the diskette ejector that prevents the door from closing if no diskette has been loaded.

WRITE

PROTECT

NOTCH

WHEN COVERED. DISKETTE

CONTENTS CANNOT

BE ALTERED

3Hoaowwoo

Figure 3 — Position for Diskette Insertion

INSERTING THE DISKETTE INTO THE 2040, 3040 AND 4040

CAUTION: NEVER APPLY POWER TO THE DISK DRIVE IF DISKETTES ARE

PRESENT (LOCKED AND SEATED) IN EITHER DRIVE 0 OR DRIVE 1.

STEP 1: Ensure that the power to the disk drive is OFF and DO NOT apply power until you complete this step. Open both disk drive doors and make sure that no diskettes are present in either drive.

STEP 2: If the preceding conditions have been met, you may apply power to the disk drive.

»LTtedlo °"

STEP 4: Once the diskette is in the slot, gently push on it until it is fully seated

"5 H ~ ~

tab

THE 4040 AND 8050 PERFORMANCE TEST

SX\'rrrriryl"dL'ruty ^deit^X

f

EXPECTED results are obtained during any steoS'th^f

Performance ^

" ™most likely cause of aproblem ran "„rnL! '^ 1 .

The until you become familiar with your disk unit.^ ' command. This is to be expected

press the RETURNkey oVyoi^r ke^^^ followed by acarriage return:

S^in re^xirif th7e"^»1nd1crr H.S"™"

example anyway. Re^nter younas^c^^^^^

successful and you may continue.

Tf^

NOTE FOR BUSINESS KEYBOARD USERS ONLY- Ym. n»„ .f

upper case character entry. Do this by typing: "

POKE 59468,12 and pressing the RETURN key

'he

correction was

STEP 1; Insert the DEMO diskette into drive 0as previously instructed.

STEP 2: ^pe: LOj^ "*",8 and press RETURN. The computer will load the first file

^^ftom the diskette in drive 0and display the foUowing:

STEP 3: Type: RUN and press RETURN. This will cause the DOS Support Program to be executed. (This program is not necessary for the disk unit to operate; it just simplifies the direct mode commands.) A brief introductory descrption of DOS

Support is presented in Chapter 3 as it applies to Chapter 3 operations. A de tailed description of DOS Support is presented in Chapter 7.

STEP 4: Insert a blank diskette into drive 1 and type;

>N1:DEM0,99

>C1=0

This procedure formats the diskette and copys all files from drive 0 to drive 1, thus creating a backup of the DEMO diskette. Remove the DEMO diskette from drive 0 and return it to its protective envelope. Remove the diskette from drive 1 and place it in drive 0. Close the door to drive 0.

STEP 5: Type: LOAD "PERFORMANCE TEST",8

The screen will display:

STEP 6: Type: RUN and press RETURN.

The program instructs you to place a blank diskette into each drive. The Per formance Test Program executes a shortened version of the test used by Commo dore in final inspection of the 4040 or 8050. The purpose of this test is to ensure that the unit is functioning correctly and will take approximately seven minutes to complete.

NOTE: Do not use diskettes containing any valuable information since the Per formance Test Program will re-format them and any data will be lost. The test program will label these diskettes "Test Disk 1" and 'Test Disk 2". These disk ettes are ready for further use when the test program is completed and the per formance test has been satisfied.

STEP 7: Press RETURN, the following will display:

STEP 8: Enter the appropriate response to the question and press RETURN.

The computer will calculate the maximum number of tracks for the particular disk drive and begin the performance test. The screen displays:

the screen displays: ® in drive 1.

*^^1® operation

NEW~ei COMMFlNri

HEW-1 COMfiRHD

OK Ci

OK 1

00.0

both IiRIVES PfiSS MECHRNICRL TEST

The computer conducts the remainder of the Performance Test and displays;

OPEN WRITE FILE ON 0

UPEN WRITE FILE ON 1 writing IiflTfl TO 0

WRITINU DHTfl TO 1

CLOSE WRITE DRTfl TO 1

OPpj REflD FILE ON 0

OPEN REflD FILE nw 1 reading DRTfl FROM 0

SCRATCH FILE ON 0

FILES SCRATCHED 1

.5=^:RATCH file ON 1 files SCRATCHED 1

WRITE TRACK xx ON 0

hdJJI ON 1

WRITE TRACK 1 ON 1

RERIf TRACK xx ON 0

READ TRACK xx ON 1

RERD track 1 ON 0

READ TRACK 1 ON 1

OK 0

OK 1

OK.0

OK 0

OK 1

OK 0

OK 1

OK 0

01.00

00. 00

00,00

00. 00

00.00

00. 00

00- 00

01,00

OK 0 00.00

OK 1 00.00

OK 0 00. 00

OK 1 00. 00

OK 0 00.00

OK 1

00.00

OK 0

00. 00

OK 1

00.00

UNIT HAS PflSSEIi PERFORMANCE TEST!

TUW^IN.i'^IJ^Po^F?'''

READV,

STEP 10: ^L7/-tp:a?re

P™'-«ve jackets. The floppy has

P"test, return to a.Msfactory conclusion to the Performanr^^:tXTct'y^^^^^^^^^^^^

THE 2040 AND 3040 PERFORMANCE TEST

When you have successfully completed the Power-On test, proceed with the Performance

Test. Don't worry if you don't fully understand exactly what is happening in this test. At this point, enter the commands just to get a feel for what you can do with your disk. If UN

EXPECTED results are obtained during any step of the test, stop and start over again. The most likely cause of a problem isan improperly entered command. This is to be expected until you become familiar with the procedure.

All commands entered via the keyboard must be followed b a carriage returni Dress the

RETURN key.

NOTE: Enter the commands 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.

STEP 1: Insert the DEMO diskette into drive 0 as previously instructed. Insert a blank diskette into drive 1. Close both drive doors.

STEP 2: Type: OPEN 1,8,15

This command opens logical file 1 on device 8. The secondary address of 15 opens the command channel to the device. The screen displays your entry followed by

READY.

NOTE FOR BUSINESS KEYBOARD USERS ONLY: To set the computer for upper case character entry type:

POKE 59468,12 and press RETURN

Although it is not absolutely necessary to give this command prior to communi cating with the disk drive, it does permit easy entry. In addition, the examples in this manual can be duplicated exactly. (POKE 59468,14 will return the user to lower case letters.)

STEP 3: Type: PRINT#1,"I0"

This command initializes drive 0. The initialization procedure places the magnetic head of the drive in the proper position above the diskette. This process is neces sary each time the diskette is removed and inserted into the drive. The computer displays your entry, then the word READY.

STEP 4: Type: LOAD"*",8 and press RETURN.

The screen displays:

STEP 5: Type: RUN.

This causes the DOS support program to be executed. (This program is not neces sary for the disk unit to operate, it just simplifies the direct mode commands.) A brief introductory discussion of DOS Support is presented in Chapter 3 as it applies to Chapter 3 operations. A detailed description of DOS Support is pre sented in Chapter 7.

STEP 6: Type: >D 1=0

This commands the disk drive to make a backup copy of the DEMO diskette.

Remove the original DEMO disk from drive 0 and return it to its protective envelope. Insert the backup disk into drive 0.

STEP 7: Type: >10

This command initializes the backup diskette.

STEP 8: Type; LOAD"0:DIAGNOSTIC BOOT",8

This command loads the Diagnostic Boot program from the diskette in drive 0 into memory. The screen displays your entry and:

Concurrent with the display, the drive 0 indicator lights and the drive 0 motor runs.

STEP 9: REMOVE THE BACKUP DISKETTE BEFORE PROCEEDING TO THE NEXT

STEP.

STEP 10: Type: RUN and press RETURN

Follow the directions on the screen. If all three indicators flicker continuously, the test is passed. If all indicators remain lit in a steady pattern, the directions on the screen can be used to find the problem area. After 30 seconds of opera tion, reset the disk drive by turning the computer's power switch OFF, then ON.

STEP 11: Simultaneously press SHIFT and CLR/HOME to clear the screen. Use the POKE command described earlier to set the computer for upper case character entry.

STEP 12: RETURN THE BACKUP DISKETTE TO DRIVE 0

STEP 13: Type: >10

This command initializes the diskette in drive 0.

STEP 14: Type:/0:PET DISK

This loads the PET DISK program from the diskette in drive 0 into memory.

The screen displays your entry and:

STEP 15: Type: RUN

The PET DISK program is displayed until terminated. Note that you can hear the drive 0 motor running intermittently as each program loads the next.

STEP 16: Press the RUN/STOP key.

Simultaneously press SHIFT and CLR/HOME. This completes the 2040 and

3040 performance test.

NOTES

Chapter

LEARNING HOW TO USE

YOUR FLOPPY DISK DRIVE

Your CBM Floppy Disk Drive adds and enhances your computing power with added storage and file handling capability and is controlled directly with:

• BASIC commands entered via the keyboard,

• BASIC statements within programs, and

• special disk commands.

In this chapter you will learn how to apply those commands and statements. This chapter is organized in such a way that the functions and format ofdisk commands are described in a manner which permits the user to perform disk-related tasks. For BASIC 4.0 users, those

BASIC commands which correspond to each disk maintenance command are also discussed.

Before using your floppy disk make sure you know how to:

1. operate your Commodore Computer,

2. do elementary programmingin BASIC, and

3. open and close files.

NOTE: The BASIC statements described in this chapter apply specifically to the 2040,

3040,4040, and 8050. Certain of the commands and statements may follow aslightly dif ferent format or produce different results from those described herein when they are used with the computer or with other peripherals. Consult the appropriate manual for the exact usage of these commands and statements in other applications.

This chapter will first acquaint the user with those fundamental disk commands that per form disk maintenance and file manipulation and will then progressively advance toward an understanding of those BASIC commands used for data handling. Approached in this man ner, 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 depend to a large degree upon how well the fundamentals have been mastered.

To facilitate your understanding and mastery of Commodore BASIC, two computer terms arestressed in this Chapter: Block Availability Map (BAM) and Disk Operating System

(DOS). Although these are conventional terms, they will be briefly discussed as they relate to Commodore Floppy Disk Usage.

§ \

THE BLOCK AVAILABILITY MAP (BAM)||

The BAM is a disk memory representation of available and allocated space on a disk. When thesystem stores information on a disk, the BAM will beautomatically referenced by the

DOS to determine whatspace is available and how many blocks can be allocated. If suffi cient space isavailable to store a given file, it will bestored on the disk and the BAM updated to account for the space allocated. However, if the DOS detects that a file 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 initializa tion. The BAM is stored on diskette in varying locations depending upon the drive used:

Model

2040,3040,4040

BAM Location and Memory Requured

Track 18, Sector 0

128 bytes

8050 Track 38, Sector 0 and 1

2 Blocks

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 when a program issaved or a CLOSE or DCLOSE is performed on a new RELative or SEQuential data file. Since the 8050 hastwo blocks available for the BAM, only one block of the BAM is loaded into memory at a time. When updated, this block is written to the disk and the other block loaded into memory. This interchange of information between the two BAMs, one in DOS memory and the other on disk, enables the system to maintain a record of free and allocated space on the disk.

This description of the BAM can only stress the importance of initialization when using either the 2040 or 3040. Strict attention to this basic rule will enable the user to benefit from the advantages of developmg good programming techniques as wellas to develop a better understandingof the relationship of one element of the system to another.

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 diskso 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.

There is another function of DOS called DOS Support which was used during hardwue checkout in Chapter 2. Review the Performance Test procedure and observe the special sym bols of DOS Support which were used to duplicate and initialize the disks before these pro cedures were fully explained to the user. Because of its ease of use, DOS Supportsymbols

were easier to implement at that point than attempting to explain the programming pro cedures theyreplace. It is now appropriate to briefly discuss how DOS Support can enhance and simplify your knowledge of operating your Commodore computer.

The first file on the TEST/DEMO diskette that comes with your disk drive is the Universal

Wedge program, often referred to as DOS SUPPORT. This program, when loaded into com puter memory, permits the user to enter abbreviations for many disk commands.

For example, disk commands which would normally be transmitted to the disk using the

PRINT#lfn "commandstring" format may be transmitted via DOS SUPPORT by preceding the command with > or Typing slash (/) followed by a program name and RETURN will cause DOS SUPPORT to load that program into memory. Replacing certain disk commands with DOS Support special symbols can simplify learning about your Commodore computer by providing a faster methbd to communicate virith the disk. Chapter 7 contains detailed instructions concerningthe use of these special symbols and their limitations.

DISK MAINTENANCE COMMANDS

Thefollowing disk commands permit the user to perform file manipulation and disk maintenance.

Diskette

Level

BASIC

COMMAND

NEW

INITIALIZE

LOAD"$0"

. VALIDATE

DUPLICATE

FUNCTION

Formats a disk

Prepare diskette for use

Read disk directory

Reconstruct Block Availability

Map (BAM)

Duplicates a diskette

BASIC 4.0

DIRECT COMMAND

HEADER

Chapter

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 data to and from the disk drive.

These commands are available for ALL versions of Commodore BASIC:

0PENlfn,8^,"dr:fn,t^/w"

CLOSElfn

L0AD**dr:fn",8

SAVE"dr:fn",8

VERIFY"dr:fn",8

PRINT#lf

GET#lfn

INPUT#

These commands are available ONLY in BASIC 4.0:

DOPEN#lfn,"fn"

DCLOSE#lfn

DLOAD"fn"

DSAVE"fn"

RECORD#lfn,R,B

Where: lfn=logical file number (any number between 1 and 255) fn=file name supplied by user x=dr=disk drive number (1 or 0): both Dx and dr default to 0

8=device number (8 for disk, 2 for second cassette, 4 for printer) sa=secondary address lf=logical file

All upper-case characters shown in format are essential for the properexecution of a com mand and must be tj^ed by user. These commands are entered via the keyboard using unshifted characters o^y. On the CBM Business Model they will appear inlower case.

B^IC 3.0 commands are upward compatible with BASIC 4.0 commands. Each command will be defined along with a brief example to illustrate theiruse. As soon asyour dual drive floppy disk isattached to your computer and has passed the performance test, we encourage you to try the examples and procedures.

SAVE and DSAVE (Writing a Program to a Dislcette) ^

If apropam is in computer memory, itcan be moved to adiskette for storage. This is accomplished with the SAVE (any Commodore BASIC) or DSAVE (BASIC 4.0) commands.

transferred w^h the SAVE or DSAVE commands are automaticaly designated by the DOS as aprogram (PRG) file. Both commands transfer PRO files from the computer's memory to the specified diskette. You must specify the drive number, the program name.

Md the device number. The device number will default to device 1which is the tape unit if

It IS not specified.

TTie format of SAVE is:

SAVE"dr.fn",dn

Where: dr=is the disk drive number. It must be 0 or 1.

fn=is any file name of 16 characters or less you wish toassign to the file to be transferred to the diskette. Blanks are counted as characters.

dn=is the device numberand it must be 8.

This following example illustrates creating aone line program, SAVEinc it on the disketfp in

drive 0under the name TESTPROG, and VERIFYing that it LrfsMeX dtek

Example: 10?'THIS IS A TEST"

SAVE"0:TESTPROG",8

VERIFY"0:TESTPROG",8

The DSAVE command performs the same function as SAVE, but is valid oniv with aCom.

modore dislt system and BASIC 4.0.

The format is:

DSAVE"fn"Ddr

Tliis command wiU save afile named "fn" on the floppy disk in drive 0or 1. The fUe name

"fn",may be any name of16characters orless.

«" or a. ine rue name,

LOAD and DLOAD (Reading a Program from a Diskette)

IrB^clo^lS^'Sc'4S

The LOAD and DLO^ commands transfer PRG fUes from the specified diskette to the

""s'specify the drive number, the program name,and thedevice

LO^is^ device number will default to unit 1which is the cassette unit. The format of

LOAD"dr:fn",dn

Where: dr=is the drive number from which you are loading data. It must be 0or 1.

fn~is the file name previously specified in the SAVE command and/or stored in the disk directory.

dn=is the device number and it must be 8.

The following example illustrates how a program is loaded from the diskette into the com puter memory, then executed. To do this example, first type NEW and depress RETURN key to clear your computer's memory so that you can see that it really works. Don't con fuse the NEW command in BASIC with the NEW disk command used to format your disk.

Example 1: LOAD*'0:TESTPROG",8

READY.

RUN

THIS IS A TEST

The DLOAD command transfers performs the same function as LOAD, but is specifically designed for a Commodore disk unit using BASIC 4.0. The device number will default to 8 if not specified. The drive number will default to 0 is not specified.

DLOAD"fn",Ddr

A successful LOAD or DLOAD closes all open files. Therefore you must give a new OPEN command in order tocontinue communicating with the disk drive command and error channel.

The format of VERIFY command is:

VERIFY"dr:fn",8

This command verifies that a file named "fn" stored on a floppy disk contains the same information which is stored in the computer's memory. This command is the same as the

VERIFY command used with the tape cassette. Once again, dr refers to the drive number, either zero or one. Note that the format of this command specifies that the drive number be placed before the filename. The 8 at the end of this command is the device number (8 for disk, 2 for second tape cassette).

STEP 1: Write a short program and save it on a diskette in drive 1 under the name "test" using the procedure described under the section on SAVE.

NOTE: It is important that the program in memory is not changed in any way between the save and verify operations.

STEP 2: Type: VERIFY "1:TEST",8

Once verified, the screen displays:

Ka verify error occurs, reSAVE the program and verify it again.

VERIFY may also be used in the format:

VERIFY"*",8

in order to perform verification of the last fUe saved without re-typing the fUename. Con-

firm by following these steps:

STEP 1: Write a short program and save it.

STEP 2: Clear the screen.

STEP 3: Type: VERIFY 8

The VERIFY function will be performed comparing the last file saved to the content of memory.

OPEN

This command sets up a correspondence between alo&cal fUe number and a on disk. It also reserves the buffer space within the disk unit tor operations on the file bemg opened.

Theformat of the complete OPEN command is:

OPENlfn,dn,sa,"dr:fn,ft,mode"

Where: lfn=the logical file number dn=the device number; in this case 8 sa=the secondary address. It may be any number from 2to 14 and may be used either for input or output as specified in mode. See note below dr=the drive number: 0 or 1 fn=the name of the file.

ft=the fUe type. Itmay be SEQ (for sequential), USR (for user), REL (for rela-

tive) or PRG (for program).

mode describes how the channel is to be used. It may be either READ (R) or

WRITE (W).

NOTE: Secondary address 15 is the command and error channel and has speci^uses which

are discussed in subsequent chapters. Secondary addresses 0and 1 are reserved by the operating systems (BASIC and DOS) for LOADing and SAVEmg programs.

Examples: OPEN2,8,2,"0:FILE1,SEQ,WRITE

OPEN3,8,9,"l:TESTDATA,PRG,WRITE*?

OPEN8,8,8,"0:NUM,USR,READ*' ^ ^ ' ^

p»,i •! .••;•• •-1

The contents of an existing file (on 4040 and 8050 only) may be replaced by preceding the drive number with an at sign (@) in the OPENcommand.

OPEN3,8,5,"@0:JDATA,USR,WRITE''

If the specified file does not exist, then normal OPENing procedures are executed.

You can also assign some of the OPEN parameters to a variable name as illustrated in these examples:

Example 1: FL$="0:FILEA,SEQ,READ"

OPEN1.8,14,FL$

Example 2: FL$="0:FILEA"

0PEN1,8,14,FL$+",SEQ,WRITE"

The preceding methods are convenient when it is necessary to open several channels to the same file name.

The DOPEN command is available only to BASIC 4.0 users. When used with either a 4040 or 8050, DOPEN may be used to create relative files or sequential files of fixed length.

The format of DOPEN is:

DOPEN#lfn,"fn",Ddr,Lrl (,0NUdn) (.W) i Where: Ifn, fn, and dr are the same as defined for OPEN.

Lrl defines the record length as equal to rl

ONUdn specifies the device number equal to dn (with default device being 8)

Wmay be specified to mean virite mode. If Wis not specified for sequential files, the file will be opened to read.

DOPEN is not available for the standard 2040 or 3040.

" "

The CLOSE command closes a file opened by the OPEN command. Its format is:

CLOSE Ifn

Where: lfn=the logical file number ofa file opened by the OPEN command.

Always close a file after working with it. You are not allowed to have more than ten open files mthe computer and five in the disk drives, so it is prudent to make a habit of closing files as soon as possible. This way you will always have the maximum number of files avail able for use.

DOLOSE

The DOLOSE command is available only to BASIC 4.0 users. This command closes files opened with the DOPEN command.

The format of DOLOSE is; It

-yf DCLOSE#Ifn

Where: lfn=the logical file number of the file to be closed.

The DOLOSE command may also be used in this format:

DOLOSE ONUdn

Where: dn=the device number of the disk unit (defaults to 8).

When used in this form, DOLOSE command closes all active diskfiles on the specified unit.

The following examples illustrate some applications of DOLOSEcommand:

Example 1: DOLOSE

Example 2:

Close all files currently OPEN.

DOLOSE#5

Close only logical file 5.

CLOSING THE COMMAND CHANNEL

Closing the command channel closes all channels associated with the disk drive. No other part of the 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 down by a single CLOSE command.

Example: OPENl.8.15

The command channel is opened.

Data Channels are opened for writing.

OPEHC-!.S.2..0:FILE1.SEG..WRITE"

0PEN4.8.5."G:FILE2.SEQ.WRITE"

PRINT#:::.. "IMPORTRHT DflTR"

PRIHT#4.."Ni:iRE DftTfi"

OPENS,4

?FILE OPEN ERROR?

REFinV.

A channel is opened to the printer by mistake.

An error message is displayed on the screen.

Since there was an error, all logical files in the computer are closed, but the channels in the disk drive are still open. To close the disk channels, type:

V " -

OPENI.8,15

CLOSEl

Now all data channelsin the disk drive are properly closed.

CLOSING THE DATA CHANNEL

"Hie CLOSE command closes a file and thedata or command channel assoc^jated with it.

Whenever you close a file opened witha write channel, the closing of that file writes the final block of data to the disk and updates the disk directory. When you close a file opened with a read channel, that channel is simply closed down.

NOTE: Wheii adrive is initialized with INITIALIZE, NEW, DUPLICATE, or VALIDATE, all channels associate with that drive are deleted. These commands should not be executed when there are any files open sincethe files will'b6 disrupted.

PRINT#

The PRINT# command transmits a disk command string to the drive.

The format of PRINT# is:

PRINT#fn,"commandstring"

Where: • lfn«a file previously opened using secondary address 15 t f yy: i'

''commandstring'-disk handling or disk file handling commands. These disk commands

'' are discussed in detail in Chapter 3 of this manual. '

'v;: •; ; r J;,'

PRINT# may also be used to transmit datato a previously-opened sequential or relative file.

Asemicolon must be used asa terminator for each PRINT# statement when using BASIC

3.0 to avoid sending extraneous line feeds to the diskette. These characters are written to the diskette by the BASIC PRINT# routine as part of the data terminator. It is important to beaware of thisface because the carriage return alone is seen asa terminator by the DOS.

Hieline feed isthen stored inthefile as the first character in the next record. To avoid this, use the following format:

•KxMi^e:7:Kmri^,''k)NESABC'';Cini$a3); '

The CHR$(13) is the carriage return nectary for the proper termination of the record on the disk. When this record is input, the result will be JONESABC which is the desired result.

BASIC 4.0 users do not need to follow this procedure (though no harmful ieffects will result firom it). In BASIC 4.0, any file opened with Ifn less than 128 will automatically suppress the line feed.

The following format may then be used:

PRINT#lfn,A$ -

This will produce the desired value of A$ for the record, and will not interfere with the next record.

Several variables may be written to the disk at the same time.

The format:

-V

PRINT#lfn,A$,B$,C$ will result in a single variable (A$+B$+C$) being retrieved by the input command.

The format:

•• v . " !

• ;

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

^ will result in the variables A$, B$, and C$ being separated by carriage returns, and theymay then be input as separate variables.

' i ' ; ; r

The I^UT# command isused to transfer information from an IEEE device such as the disk drive into computer memory. INPUT# is valid only when used, ina program and onl>^when referencing a logical file that has been OPENed for input.

The format for INPUT# is: •'

INPUT#lfn,A$ or INPUT#lfn,A '---v:-

Where: lfn=a file previously opened using secondaryaddress 15 '

A$=astringvariable which will conts^ 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$ ^ ' ;" ' i• ^.j .

. /

^ •••--; •• ' •

Where: A$, B$, C$ will contain the data transferred from the disk.

' ^ '

' u -

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 retrieved separately. No single string may contain more than 80 characters if it is to be INPUT.

^ >; sir?:;

Example 1: ^ . v ? - ; - ' V • •• . 5 ^

2blNPUT#2,A^^^^^^^ l :• '

Example 2:

•/ '•

' Input the next data item which must be in numeric form and «««£" the value

• to variable A.

^ ..

- : ,v?sr

\ ^^

^ ,

' . •

10INPUT#8,A$

' • ' ' • • •

Input the next data item as astring and assign itto variable A$.''^^ ^

• ' • ' '--K::-" • v-'-

;

'fh

•

-'i

• ..;.V.1^7:iC'.'.

•'J-: :0> .•' ••

••;

Example 3;

• • ' V'! ^ i' .^•'•

60 INPUT#?,B,C$

^Uv •:

'CO ;> •;,:i

;. Input the next two dataitems and assign the first to numeric variable Band the second to string variable C$.

j .

Forstrings longer than 80 characters, the GET# command must be used. =.

GET#

TheGET# command is used to transfer individual bytes of information from an IEEE device such as the disk drive into computer memory. GET# is valid only when used in a pro gram and only when referencing a file that has been OPENed.

vjTie^matof GET#'is:"

g3;G^n.A$-i4; ^ ^

oW u

Where: v^fn-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 ofinformation, which is useful for retriev ing strings which have been written to the disk in a format which is unacceptable for the

INPUT command (strings longer than 80 characters).

:'lFor'example:klOAA$=""-S

20 FOR 1=1 TO 254

. ' 30GET#lfn,A$ ;

40 AA$=AA$+A$

50NEXT < .

^ result in a" ^ring of length 254 being ix^f^erred from the

••• "

trnMi""'""

Tliell^ used piicîo a PRIITOÎNPUT#, : tion the file pointer tothe desired record (and byte) of arelative file. For example, ifrecord pomter is ret beyond the last record and PRINT# isused, the appropriate number of records are geni^ted to expand the file totheêsired recordviv^v;-;: ^^^^ < . ..

RECORD# is available only to users iequipped wtliisASIC 4.0; The format is:

I^CORD#ifn,r,b .

v , ^

Where: lfn=a logical file number of a file previously opened with the DOPEN command r=the desired record number. 4 may be either a variable name orvalue, how ever if r is a variable name, it mustappear enclosed in parentheses.

0<=r<=65535 b=the byte position desired within the record. Byte positioning is optional.

l<=b<=254

The following example illustrates how RECORD command is used with INPUT#:

Example: 10 RECORD#!,120 • H

Using the RECORD command to select the record.

20INPUT#1,A$

Input the next data item as a string and assign it to variable A$.

Adetailed example of the usage of the RECORD command for relative file manipulation is found in Chapter 6.

QUICKLOAD FEATURE (BASIC 4.0)

This command feature is valid with DOS 2 and BASIC 4.0, and either a 4040 or8050. (This command will also function properly with a retrofitted 2040.)

•^is command loads the first file on the disk in drive 0 into memory. To ensure that the first program on the diskette is accessed, the command must be the first disk command given after a cold start.

STEP 1: Turn the computer OFF, then ON.

STEP 2: Make sure the disk containing a program as the first file is in drive 0 and that the drive door is closed.

STEP 3: Simultaneously press the SHIFT and RUN/STOP keys.

The computer will initialize the disk in drive 0, search for the first program on that disk, and load it.

When using this feature the computer will automatically execute the DLOAD and RUN commands and it is not necessary to enter either command.

• - v ' f .

,4 f r ' .

•i : 'f'",':

• r > •

MOVING A TAPE PROGRAM TO DISK

Tliis example illustrates a session with the computer, a tape cassette and a disk drive. The purpose is to copy a cassette program to a diskette. The program is then read from the diskette to the computer's memory and printed. It is assumed that the BASIC program was previously stored on the cassette.

Example:

Load the file from the cassette tape to the computer's memory.

Create a program file containing the program on diskette.

Erase everything from memory. (The NEW command in BASIC will clear memory; the

NEW disk command will format a disk.)

Load the program back into the computer's memory.

Run the program to verify it has been loaded.

NOTES

i/^N

Chapter

ADVANCED

DISK PROGRAMMING

This chapter provides detailed information about DOS structure and disk utility commands.

The utility commands provide the programmer with low-level functions that may be used for special applications such as special disk handling routines and random access techniques.

COMMODORE DISK OPERATING SYSTEM (DOS) l^e DOS file interface controller is responsible for managing all information between the disk controller and the IEEE-488 bus. Most disk I/O is performed on a pipelined basis, re sultingin a faster 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 ortwo disk I/O buffer areas. If either the workspace orthe buffer is not available, a NO CHANNEL error is generated. The DOS also uses the channel structure to search the directory, and to delete and copy files.

The common memory between the disk controller and the file interface controller is used as

256-byte buffer areas. Three of the sixteen buffers are used by the DOS for the Block

Availability Maps (BAM), variable space, command channel I/O, and disk controller's job queue.

•^e job queue isthe vital link between the two controllers. Jobs are initiated on the file side by providing thedisk 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 place of the job command. If thejob is unsuccessful, the file side re-enters the job a given number of times, depending upon the operation, before generating an error message.

The secondary address given in the OPEN statement isused by DOS as the channel number.

The number the user assigns to a channel is only a reference number that is used to access the work areas, and is not related to the DOS ordering of channels. The LOAD snd SAVE statements transmit secondary addresses of0 and 1, respectively. The DOS automatically

48 interprets these secondary addresses as LOAD and SAVE functions. Unless these functions are desired when opening files, avoid secondary addresses of 0and 1. The remaining num bers, 2 through 14, may be used as secondary addresses to open up to five channels for data.

DISK UTILITY COMMAND SET

The disk utility command set consists of the following commands:

Commands

Abbreviations General Format

BLOCK-READ

B-R "B-R:»ch,dr,t,s

BLOCK-WRITE

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

BLOCK-EXECUTE

BUFFER-POINTER

B-E

B-P

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

"B-P:»ch,p

BLOCK-ALLOCATE

B-A

"B-A:"dr,t,s

BLOCK-FREE

B-F

"B-F:"dr,t,s memory-write

M-W

"M-W* 'adl/adh/nc/data memory-read

M-R

"M.R"adl/adh memory-execute

USER

Where:

M-E

"M-E"adl/adh

U "Ui:parms" ch-the channel number in DOS: identical to the secondary address in the associated OPEN statement.

dr=the drive number: 0 or 1 number, the sector ranges 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 ui, (decimal 1).

i=the index to the User Table.

parms=the paramc^ers associated with the Ucommand (optional).

The values used in conjunction with the memory commands exist in the 2040, 3040, and

4040 as hexidecimal values and must be transmitted as CHR$(n), where n is 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 isgood practice to use this format when using variables or constants.

Asimplied in the preceding format, these commands may be abbreviated to the first charac ter of each of the key words. Abbreviations only are accepted for those commands shown in lower case. The parameters associated with each command are searched for starting at a colon (:), or in the fourth character position if a colon is not present. The example follow ing shows four ways that thesame block-read command may be given.

NOTE: If using a 4040initialize the disk before the buffer read or write.

Examples: "BLOCK-READ: "2,1,4,0

"B-R"2,1,4,0

"B.R"2;1;4;0

"B-READ:"2;1;4;0

Parameters following the key words within quotation marks may be separated by any com bination of the following characters:

Character Name

Skip

Space

Keyboard Representation

Space bar

Comma

The use of these characters permits sending both ASCII strings and integers.

Parameters not within the confines of quotation marks should be separated by semi colons (;).

In the following discussions, a PRINT# is assumed in all examples.

BLOCK-READ

T^is diskette utility command provides direct access to any block on a diskette in either disk drive. Used inconjunction with other block commands, a random access file system may be created through BASIC. This command finds the character pointer in the 0-position ofthe block. When a character in this position is accessed with GET# orINPUT#, an Endor-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;l;18;0

After using

Reads the block from drive 1, track 18, sector 0into channel 5 buffer area.

READ to transfer the data to the buffer, the data may be transferred to

SToKaS) """

The U1 command described under USER is similar to the BLOCK-READ command.

BLOCK-WRITE

men this command is initiated, the current buffer pointer is used as the last character

?

l'"j- I® t''® new The buffet is then written to the

The format B-W: "ch;dr;t;s is illustrated in the following example.

Example: "B-W:"7;0;35;10

Writes channel 7buffer to the block on drive 0, track 35, sector 10: s'sfablewith DOS 2.This includes the 4040 and all 2040/3040

retrofits. The BLOCK-WRITE command is replaced by the U2 command for the 4040.

BLOCK-EXECUTE designed routines to reside on diskand be

""• ^-E is really a B-R with an addition. The FUe

^Mution must be terminated with areturn from the subroutine (RTS) instruction. Future

system extensions or user-created functions may implement this command.

The format B-E: "ch;dr;t;s is illustrated in the following example.

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

Reads ablock from drive 1, track 1, sector 10 into channel 6buffer and exe cutes Its contents begmnmg at position 0 in the buffet:

BUFFER-POINTER

records, individual records may be set for transmitting or receiWng datr

The format B-P;"ch,p is illustrated in the following example.

Example: "B-P;"2;l

buffer*^"""®' ^ ""e beginning of the data area in the direct access

o f

BLOCK-ALLOCATE

Theappropriate 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. The updated BAM is written to diskette upon the closure of a write file or the closure of a direct access channel.

If the block requested has been previously allocated, the error channel indicates the next available block (increasmg track and sector numbers) with a NO 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:"l;10;0

Requests that block (sector) 0 of track 10 be flagged asallocated on the diskette in drive 1.

NOTE: The error channel should always be check when using BLOCK ALLOCATE, so that if the block is already allocated, it will not be overwritten. Ifthe block is allocated, the error message will also indicate the next available block.

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

Reads the next track and sector, respectively, into ET and ES, assuming that lfn=15 has been previously OPENed to the disk error channel.

MEMORY

All three MEMORY commands are byte-oriented so that the user may utilize machine language programs. BASIC statements may be used to access information 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: "M-W:"CHR$(00)CHR$(18)CHR$(4)CHR$(32)CHR$(0)CHR$(17)CHR$(96)

Writes four bytesto buffer 2 ($1200 or decimal 4608):

Memory-Read O

The byte pointed to by the address in the command string may be accessed with this com mand. 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 next GET# from the error channel

(secondary address 15) transmits the byte. An INPUT# should not be executed from the error channel after a MEMORY-READ command until a DOS command other than one of the MEMORY commands is executed.

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 or decimal 128):

Memory-Execute

Subroutines in the DOS memory may be executed 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 execution of code beginning at $3180.

USER

This command provides a link to 6502 machine code according to a jump table pointed to by the special USER pointer. Refer to Table 5. The second character in this command is used as an index to the table. The ASCII character 0 through 9 or A through 0 may be used.

Zero sets the USER pointer to a standard jump table that contains links to special routines.

The special USER commands U1 (or UA) and U2 (or UB) can be used to replace the

BLOCK-READ and the BLOCK-WRITE commands.

The format of U1 is:

"Ul:"ch;dr;t;s

U1 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 of U2 is:

"U2:"ch;dr;t;s

U2 writes a buffer to a block on the disk without changing the contents of position 0 as

B-W does. This is useful when a block is to be read in (with B-R) and updated (B-P to the field and PRINT#), then written back to diskette with U2.

Refer to the random access example in Chapter 6 for an application of the U1 and U2 commands.

^0^

USER

DESIGNATION

Table 5. Standard Jump Table

ALTERNATE

USER

DESIGNATION

UP jump to jump to jump to jump to jump to jump to jump to

FUNCTION

BLOCK-READ replacement

BLOCK-WRITE replacement

2040/3040

$1300

4040 8050

$1300

$1303

$1306

$D008

$DOOB

$DOOE

$1303

$1306

$1309

$130C

$130F

$D0D5 $10F0 power up vector

$10F0

$1300

$1303

$1306

$1309

$130C

$130F

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 downloaded using the M-W command. Locations D008, DOOB, DOOE, and D0D5 arelocated in the expansion ROM slot in the 2040/3040 and USER commands may be used to access a ROM or EPROM located in that position. Location lOFO is the location of the NMI vector in the 4040 and 8050.

^The

Table 6. Block Distribution By Track

2040, 3040

Track number

Block or

Sector Range

Ito 17

18 to 24

25 to 30

31 to 35

Oto 20

Oto 19

Oto 17

Oto 16

4040

Track number

Block or

Sector Range

Ito 17

18 to 24

25 to 30

31 to 35

Oto 20

0 to 18

Oto 17

Oto 16

8050

Track number

Block or

Sector Range

Ito 39

40 to 53

54 to 64

65 to 77

Oto 28

Oto 26

Oto 24

Oto 22

JlAY tSoS""'"

Total

T&S. provided

" inWing information obtained using tlie DIS-

I

Table 7. 2040, 3040 BAM FORMAT

Track 18, Se ctor 0.

BYTE

0,1

CONTENTS

18,01

DEFINITION

Track and sector of first directory block.

2 1 Indicates version 1 format.

3 0 Null flag for future DOS use.

4-143 ♦Bit map of available blocksfor tracks 1-35.

*l=available block

O=block not available

(each bit represents one block)

Track 18, Sec

;tor 0.

BYTE

144-161

CONTENTS

DEFINITION

Disk name padded with shifted spaces.

162-163

Disk ID.

164-170 160 Shifted spaces.

171-255 0 Nulls, not used.

Note: ASCII characters may appear in locations 180 thru 191 on some diskettes.

Table 9. 4040 BAM FORMAT

Track 18, Sector 0.

BYTE

0,1

4-143

CONTENTS

18,01

DEFINITION

Track and sector of first directory block.

ASCII character A indicating 4040 format.

Null flag for future DOS use.

Bit map of available blocks for tracks 1-35.

*l=avaaable block

O=block not available

(each bit represents one block)

Table 10.4040 DIRECTORY HEADER

Track 18, Sector 0.

BYTE

144-161

CONTENTS DEFINITION

Disk name padded with shifted spaces.

162-163 Disk ID.

164

165,166

166-167

160

50,65

160

Shifted space.

ASCII representation for 2A which is DOS version and format type.

Shifted spaces.

171-255 0 Nulls, not used.

Note: ASCII characters may appear in locations 180 thru 191 on some diskettes.

4,5

Table 11. 8050 DIRECTORY HEADER BLOCK

Track 39, Se

'ctor 0.

BYTE

0,1

CONTENTS

38,0

DEFINITION

Track and sector of first BAM block.

ASCII character Cindicating 8050 format

Null flag for future DOS use.

6-21

22,23

24,25

160

Unused.

Disk name padded with shifted spaces.

Shifted spaces.

27,28

160

50,67

Disk ID.

Shifted space.

29-32

33-255

160

formaVl^pf

Shifted spaces.

Nulls, not used.

version and

Table 12. 8050 BAM FORMAT

First BAM block: Twck 38, Sector 0.

BYTE

CONTENTS definition

Track and sector of second BAM block

ASCII character Cindicating 8050 format.

Null flag for future DOS

owest track number represented in this BAM

Highest track number +1 in this BAM block.

Number of blocks unused on track 1

Bit map representation of available blocks

11-255

_BAM for tracks 2-50, 5bytes per track

Second BAM block: Track 38. Sector 3

on track 1.

BYTE

11-140

141-255

CONTENTS definition

Track and sector of first directory block

ASCII character Cindicating 8050 format.

Null flag for future DOS use

track number represented this BAM block.

Highest track number +1 in this BAM block.

Number of blocks unused on track 51

Bit map representation of available blocks

*BAM for tracks 52-77, 5bytes

per track.

on track 51.

Unused.

♦STRUCTURE

OF BAM ENTRY FOR ATRACK

BYTE definition

Dit map sectors 0-7 bit map sectors 8-15 bit map sectors 16-23 bit map sectors 24-31 for track l=available

O=not available

Note; "BLOCKS FREE"

may appear in locations 180 thru 191 on some diskettes!

ZONES to have read firstblock fourdensity

DISK

BAMAREA

AVAILABLE accordingto

8050 information).The

iswritten ifchanges mustbe tosee memory,it memory.

currentblock

ZONE thru77.

pertrack

DOSchecks theDOS made,the block,the currentlyin

BAM

275

299

29DIRECTORY

2052BLOCKS

297

1131 readinto havebeen blocknot

TOTALSECTORS theother isthen

Ifchanges aBAM readingin accessto

BAMblock tracks51 ofsectors

BAMstructure blocks(see currentblock.

SECTORS/TRACK

NUMBEROF thesecond, oftwo variablenumber

50and usesa

1thru madeup BAMis diskformat

54-64

51-53

65-77

40-50

1-39

RANGE

TRACK diskette.Before

DOSrequires

Theother zones.The

The8050 representstracks fromthe

Whenthe thediskette.

BYTE

0,1

2-31

34-63

66-95

98-127

130-159

162-191

194-223

226-255

*STP F Tr^rr TT>I? /-ira

BYTE

CONTENTS

128+type

Table 13. DIRECTORY FORMAT

Track 18, Sector 1 for 4040

Track 39, Sector 1 for 8050 definition

Track and sector of next 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

1,2

3-18

19,20

DEFINITION

?YPEr

1 - SEQential

2 = PROGram

3 = USER

4 = RELative

Track and sector of 1st data block.

File name padded with shifted spaces.

22-25

26,27

block!™

Relative file only: Record size.

Unused.

28,29

sector

file when OPEN® is in

Number of blocks in file: low byte, high byte.

«'«•

n rs.

BYTE

0,1

2-256

Table 14. SEQUENTIAL FORMAT

DEFINITION

Track and sector of next sequential data block.

254 bytes of data with carriage returns as record terminators.

BYTE

0,1

2-256

Table 15. PROGRAM PILE FORMAT

DEFINITION

Track and sector of next block in program file.

254 bytes of program info stored in CBM memory format (with key words tokenized). End of file is marked by three zero bytes.

Index

Hole

SECTOR

NOTE;

Not to scale

POINTERS TO LINK

TOGETHER ALL BLOCKS

SYNC

TRACK SECTOR CHECK

SUM

GAP!

SYNC 254 BYTES

OF DATA

Figure 4 2040,3040,4040 Format: Expanded View of aSingle Sector

CHECK

SUM

&ifii"nr:S for the 2040.

characters. Blocks within thesame file are linlrpH f «

block pointer. By point"nrtrthelocatio^ iffhf system to retrieve data from non-contieuous bIork«*R f ^

file triggers asearch forTn^ZwhSf

TT

consisting of 256 stored

pointers enable the

related blocks until the entire filp ic jieeamki j J j utilizes block pointers to locate

SEQ. and USR Z utmzeThis fo™^ A" PRO, a

35 tracks (or rings) of sectors per track will vary (as illustrated in TaMs Rt ^ f numbered 1 to 77. The number

ference and recording fre^ncy differences in track circum-

^3^ o

Index

Hole

SECTOR

NOTE:

Not to scale

POINTERS TO LINK

TOGETHER ALL BLOCKS

WITHIN A FILE

SYNC 08 IDl ID2 TRACK SECTOR

CHECK-

SUM

GAPl SYNC 07 o n

254 BYTES

OF DATA

CHECK

SUM

GAP

Figure 5 —8050 Format: Expanded View of a Single Sector

Figure 5illustrates an expanded view of asingle sector on adiskette formatted for the 8050.

In addition to other information, each sector contains a data block consisting of 256 stored characters. Blocks within the same file are linked together by means of a two character block pointer. By pointing to the location of the next data block, block pointers enable the system to retrieve data from non-contiguous blocks. Retrieving the first data block within a file triggers a search for the next data block which, in turn, utilizes block pointers to locate r^^ed blocks until the entire file is assembled and made available for display. All PRG

SEQ, and USR files utilize this format.

Adata block is addressed by track and sector. A2040 diskette contains 35 tracks (or rings) numbered 1 to 35 while an 8050 diskette contains 77 tracks numbered 1 to 77. The number ofsectors per track will vary (as illustrated inTable 6) due to differences in track circumference and recording frequency.

The 80M maintains system files on tracks 38 and 39 wliich contain the BAM, diskette name, ID, and file directory. The BAM, resident in the first 255 bytes ofsectors 0 and 3 of toack dS, monitors available and occupied storage locations on diskette. The file directory header bkMk, beginning onsector 0 of track 39, contains the diskette name and ID within the first 30 bytes.

S310N

i.

Chapter

ADVANCED

FILE HANDLING

In the preceding chapters, you learned how to manipulate files on the disk, and were shown the format of commands used to create and update files. In this chapter, you will utilize these skillsin a file handlingapplication usingrandom or relative access.

SPECIAL OPEN AND CLOSE

STATEMENTS FOR DIRECT ACCESS

The BASIC statements (after initializing the disk):

OPEN2,8,4,"#» o r

OPEN2,8,4,"#12"

H open a channel to one buffer, to be used with the block commands. In the first example, the first available buffer isallocated to channel 4, The second example is an attempt to allo cate buffer 12 to the channel. If the buffers are not available, a NO CHANNELS error con dition is generated. The explicit buffer allocation can be used to reserve a buffer for position dependent code as in the case of an EXECUTE command.

Execute a GET# statement to find the number of the allocated buffer. The byte trans mitted is the buffer number. A buffer number may only be obtained PRIOR TO any write or read operations to that buffer.

The CLOSE statement clears the OPENed channel and writes the BAM to the diskette that was last used bythat channel. To avoid confusion, limit yourself to accessing one drive with any direct access channel.

RANDOM ACCESS EXAMPLE ^

Since the BLOCK-ALLOCATE command returns the next available diskette block throuffh t eerror channel, it can be used in the allocation of records. This feature allows creating a random file without bemg concerned with the actual physical structure of the diskette

tessi's';-1'" ..

record IS stored mablock, and it is necessary to manage end-of-record pointers in BASIC

Asmaller application might take advantage of the B-R and B-W commands.

It ®f

'I"® random access program entitled "Random

"P°" ® scheme and providSk

SlS;;tSdf len-iustiffbinary f^r^d characte^telro?Sftric«^^^^^^ f" ''.T^ '

^paSwrh1Zt"-The^^^^^

fUename DUPLICATE must be performed, since the DOS is unable to COPY without a

To Create A File

STEPl: Insert the TEST/DEMO disk in drive 0.

STEP 2: ^pe: OPEN15,8.X5

and press RETURN

Opens the command channel and initializes the diskette.

STEPS: ^pe:LOAD"0:R^OM1.00",8 and press RETURN

inis command loads the random access program.

STEP 4: Insert a blank diskette into drive 1.

STEP 5: Type; PRINT#15,"N1:MAIUNG LIST" and press RETURN

STEP 6: Type: RUN and press RETURN

The screen displays: "DO YOU WISH TO CREATE A FILE"?

STEP 7: Type: Y and press RETURN

The screen displays: "RANDOM FILE NAME"?

STEP 8: Type the file name: PHONE LIST

The screen displays: and press RETURN

"KEY FILE DRIVE NUMBER"?

STEP 9: Type: 1 and press RETURN

The screen displays: "RANDOM FILE NUMBER"?

STEP 10: Type: 1 and press RETURN

The screen displays: "ENTER ID OF RANDOM DISK"?

STEP 11: Type: CS and press RETURN

The screen displays: "NUMBER OF RECORDS"?

STEP 12: Type: 10 and press RETURN

For this example, ten was entered since this is the MAXIMUM number of records the file can contain. If less records are needed, specify a number less than ten.

The screen displays:

STEP 13: Type: 4

"NUMBER OF FIELDS PER RECORD"?

and press RETURN

This is the number of 'items' each field contains.

The screen displays: "INPUT FIELD NAME, FIELD SIZE, FIELD TYPE".

TYPES: 0=BINARY, 1=NUMERIC, 2=ALEHA

FIELD 1?" enter: NAME,20,2 and press RETURN

FIELD 2?" enter: PHONE,15,2 and press RETURN

FIELD 3?" enter: ADDRESS,40,2 and press RETURN

FIELD 4?" enter: COMMENTS,40,2 and press RETURN

To Add A Record

"WHOSE RECORD DO YOU WISH TO SEE?

STEP 1: The screen displays:

Press RETURN.

The screen displays:

STEP 2: Type: COMMODORE

The screen displays:

«****aDD RECORD****"

NAME"?

and press RETURN

"PHONE"?

STEP 3: Type; 727-1130 and press RETURN

The screen displays: "ADDRESS"?

STEP 4: TVpe: 3330 SCOTT BLVD SANTA CLARA OA. 95051 and press RETURN

The screen displays: "COMMENTS"?

STEP 5: TVpe: MANUFACTURES MICROCOMPUTERS and press RETURN ftillOTimN record do you WISH TO SEE'?

The screen displays: "****ADD RECORD****"

REtS 'I®®''®''nswe. For example: smith and press

PHONE"?

Enter the phone number: 999-356-1012 and press RETURN

^^P^rItURn"'" GATOS CA. 95030

STEP 6:

PERJPH^ En'ef acomment. For example: MANUFACTURES

"WHOSE RECORD DO YOU WISH TX) SEE"?

The screen displays: «****aDD RECORD****"

®"'®'"'®''®®''^"ame. For example: JONES and press

PHONE"?

Enter the phone number: 999-268-1795 and press RETURN

^^SetuRn"'®' cCSSS^'"

SAN JOSE CA. 95117 manufactures

To See A Record

The computer displays: "WHOSE RECORD DO YOU WISH TO <5PF'»?

Enter: COMMODORE and press RETURN ^

To Change A Record

After displaying the record, the screen displays: "ANY MODS"?

STEPl: Type: YES and press RETURN.

The screen displays: "WHICH FIELD"?

Enter the number of the field you wish to change.

^

STEP 2: Type: 4 and press RETURN.

The computer displays that field:

STEP 3: Press RETURN.

US HEADQUARTERS

The screen display asks if there are; "ANY MODS".

STEP 4: If the record is correct, type: NO and press RETURN

The screen displays:

Type: /DIR and press RETURN

Getting The Directory of Listings

"WHOSE RECORD DO YOU WISH TO SEE"?

The computer displays the directory.

The computer displays:

Type: // and press RETURN. The program ends.

Ending The Program

"WHOSE RECORD DO YOU WISH TO SEE"?

RELATIVE FILES 4040, 8050

Direct access of relative files isa method that allows the programmer to position to any record on the disk relative to the beginning of that file. Compare this method to the stan dard procedure of having to search each track and sector for the desired information and it becomes apparent that such a relative handling method would result in a great reduction in the amount of time required to find a specific record stored on disk. This reduction in the amount of time required to locate and fetch a file through the application of relative file handling techniques frees the user from the major objection to using sequential disk files: excessive "look up" time.

Both DOS 2 and 2.5 (4040 and 8050) are capable ofhandling relative files and should signi ficantly reduce the amount of time spent retrieving disk files.

The two main components of a relative file are the side sector chain of blocksand the data block chain. Both are linked together through forward pointerssimilar to those used in a sequential file. Record sizes, while fixed in length, may range from one to 254 bytes. The number of records is limited to the capacity of the disk but for practical purposes should not exceed 65,535.

The side sectors do not contain record information, but do contain locations of the data blocks.The record size dictates where the pointer is placed when a record number is refer enced because the record size is used in an algorithm to compute where the pointer is placed when a record number is given through the RECORD command. The side sector also contains a table of pointers to all of the other side sectors within the file. In order to move from oneside sector to another, the pointer is referenced through the appropriate DOS command, and the corresponding side track and sector read into memory. By using the information contained in the referenced side sector, the data block pointer can be located and used to read in the actual data block containing the record. The relative file data block

pointers in the side sectors aUow the DOS to move from one record to another within two

sectors and each side sector may contain pointers to 120

?«9 204 Dual Drive Floppy S Sins to be greater than the total storage capacity of that particul^ dS ^

Table 16. RELATIVE FILE FORMAT

DATA BLOCK

BYTE

0,1

2-256

DEFINITION

Trackand sector of next data block.

254 bytes ofdata. Empty records contain FF (all binary

ftp pnH if th ^ J foUowed by 00 (binary aU zeros) to

MIU (Oof PartiaUy fiUed records are padded with

SIDE SECTOR BI,OCK

BYTE

0,1

6,7

10,11

12,13

14,15

16-256

DEFINITION

Track and sector of next side sector block.

Side sector number. (0-5)

Record length.

Track and sector of first side sector (number 0)

Track and sector of second side sector (number 1)

Track and sector of third side sector (number 2)

Track and sector of fourth side sector (number 3)

Track and sector of fifth side sector (number 4)

Track and sector of sixth side sector (number 5)

Track and sector pointers to 120 data blocks.

tZanTaXK^^^^^^

automatically generated bv the DOS Thic in i

necessary toS^a fil^r^Ldlel'^ generated

record number will be

^ "ocks

For example, if the current size of the relatiie record is one data H tT*® 'J"®/diskette,

number referenced would exnand it tn 1Qfi hir^^h- fu data block long and the record

Spelling is akey feature of relative files which aids in reducing the number of disk read/

and retrieve data. Before explaming how this feature of are utilized by relative files:

^en achannel is opened to apreviously existing file, the DOS will position to

the first record provided that the given parameters match properly. The record

^ necessary on the OPEN if the file is already in existence, but mde in the DOPEN statement creating the file. If these do not match, then error

50—record not present—will be generated.

The relative channel requures three memory buffers from the system, whereas sequential files only require two. Since there are twelve channels in the system and two of these are used in directory searches and internal functions, only three relative channels can be open at one time. The highest number of buffers that can be used is ten, which limits the total number ofchannels which can be open at any one time.

If arecord was found to be on the boundary between two data blocks, that is, starting in one data block and finishing in another, then the DOS would read the first segment as well

^ any following records in the second data block. In practice, the records of most relative across data blocks. The only exceptions are record size 1,2,127, and

^4. Th^e divide evenly into the 254 size of the data block and spanning is unnecessary.

This method of spanning has the advantage of requiring no system memory overhead aside from that required for the side sector blocks in the relative files. When a record is written upon through the PRINT# statement, the data block is not immediately written out It is only witten out when the DOS moves beyond the particular data block in which that record resides. This can occur through successive printing tosequential records, or when positioning to another record outside of that particular block.

^cause of the spanning feature, it is recommended that two channels not be open to arela tive fUe at the same time ifeither channel will be writing tothe same file. An update may be made in the channel's particular memory buffer area, but the change may not be made on disk until the DOS moves that particular data block. There is no restriction on this, how ever, and in certain instances where the file is only read from, it may be advantageous to have more than one channel open to a single relative file.

printing to arecord by detecting tlie EOI signal wiiich is generated witii

51-record overflow-will be generated. Any data overflow will be truncated to fit the number of characters specified by the record size and the DOS will position to the next record in sequence. Ifthe print statement contains less characters than the record size, the remaining positions within that record will be filled with nulls. Consequently, when positioning to a record for input the EOI signal is generated from the DOS to the computer when the last non-zero is transmitted. Should the programmer desire tostore binary information, a record terminator such as carriage return will have to be used and the record size increased by one character to accommodate the terminator.

While the DOS is generating new data blocks for relative files, the requested record number

Kcompared to the number of data blocks left on the diskette. Ifthe resulting number of data blocks is greater than what is left on the diskette, then error 52-file too large-is generated.

CREATING A RELATIVE FILE

The following examples apply only to those users equipped with both BASIC 4 0 and DOS

2. In terms ofhardware, this means a 4000 or 8000 Series PET or CBM must be used as the computer and a 4040 or 8050 for the disk drive.

When arelative file is opened for the first time, the file should be initialized by the program

mer to aUow for faster subsequent access, and to assure that the DOS reserves sufficient space on the diskette for the future data. Asimple program to perform such initialization is illustrated below:

HO DOPEN#l,"FILEl",D0,L50

120 GOSUB 190

130 RECORD#1,100

140 GOSUB 190

150 PRINT#1,CHR$(255);

160 GOSUB 190

170 DCL0SE#1

180 END

190 IF DS<20 THEN RETURN

200 PRINT DS$

210 IF DS=50 THEN RETURN

220 STOP

the preceding example, line 110 creates afile with the name FILEl and arecord length

Line 130 posiUons the file pointer to record number 100 which does not yet exist The

^ ^^rPret^ as

'he first time and indicates that no INPUT

Line 150 causes record number 100 (because of the pointer positioned by line 130) to be written. During this write operation, the DOS detects that records 1thru 99 do not akeadv exist, and automatically initializes them by placing CHR(255) in the first character.

Line 170 closes the file and causes the space to be allocated in the BAM and file directory.

Unes 190-220 are the error subroutine. If DS is less than 20, no error condition exists so

r^efcrcoStsr" ^

EXPANDING A RELATIVE FILE

^ter the file has been initiaUzed, data may be written to the fUe. Initialization of afUe in

IS ma^er need be performed only once when the file is originally created. If the user wishes to expand an existing file, the same procedure would be used, with the record num

ber (hne 130 mthe example) changed to be the new last record.

The following example, when with the disk containing the file FILEl (with 100 records) in drive 0,will result in the first 100 records remaining unchanged and records containing only CHR$(255) would be generated for records 101-200.

110 D0PEN#1,"FILEl",DO,L50

120 GOSUB 190

130 RECORD#1,200

140 GOSUB 190

150 PRINT#1,CHR$(255)

160 GOSUB 190

170 DCL0SE#1

180 END

190 IF DS<20 THEN RETURN

200 PRINT DS$

210 IF DS=50 THEN RETURN

220 STOP

NOTE: When DOPEN is used on an existing file, specification ofthe record length is option al. If specified, it must match the record length set at the time the file was created or an error condition will result.

When a file is expanded in this manner, the required side sectors are also created. Side sectors are transparent to the user since they are automatically generated and accessed by the DOS.

ACCESSING A RELATIVE FILE

In order to make the relative file system practical, the user must be able to access the file for reading and writing of data. Both of these operations are simplified by relative files and both may use the RECORD command for positioning to the desired record before the operation.

To writedata to a predetermined record in a file, a constant may be used in the positioning

(line 130) as follows:

110 D0PEN#1,"FILEl",DO

120 GOSUB 190

130 RECORD#l,25

140 GOSUB 190

160 PRINT#1,"RECORD 25"

160 GOSUB 190

170 DCL0SE#1

180 END

190 IF DS<20 THEN RETURN

200 PRINT DS$

210 IF DS=50 THEN RETURN

220 STOP

The resulting record would appear as follows:

1 2 3 4 5

12345678901234567890123456789012345678901234567890

RECORD 25*

Where * represents a carriage return ( CHR$(13)).

Mowing program Ulustrates the feature which permits access to individual bytes within

110 DOPEN#1,"FILE1",DO

120 GOSOB 900

130 RECORD#!,25,1

140 GOSUB 900

150 PRINT#1,"FIELD 1"

160 GOSUB 900

170RECORD#1,25,10

180 GOSUB 900

190 PRINT#1,"FIELD 2"

200 GOSUB 900

210 RECORD#1,25,30

220 GOSUB 900

230 PRINT#1,"FIELD 3"

240 GOSUB 900

250 DCL0SE#1

260 END

900 IF DS<20 THEN RETURN

910 PRINTDS$

920 STOP places within record

25 after the above exam^" "representation of the contents of record number

12345678901234567890123456789012345678901234567890

FIELD 1* FIELD 2* PTRr n z*

Where

♦

represents acarriage return {CHR$(13)).

E™it"s's'rsfrs?ris;r•i--««.

that while itis possible to position and write first to bvteTfl^Trf h!

example, this means

possible to first write byte 20 and then byte 1 " ^OT

d "

110 DOPEN#1,"FILE1»,DO

120 GOSUB 290

130RECORD#1,25

140 GOSUB 290

150 REC0RD#1,25,1:G0SUB 290

160INPUT#1,A$;G0SUB 290

170 RECORD#1,25,10:GOSUB 290

basic input statement, the

200INPUT#1,C$:G0SUB 290

210 DCL0SE#1

220 END

290 IF DS<20 THEN RETURN

300 PRINT DS$

320 STOP

Lines 160,180, and 200 cause the stored values on disk to be read and stored in A$, B$, and C$, respectively.

It is extremely useful to be able to access a record which is determined during program operation. The following routine illustrates a procedure to query the operator for a record number and data and to write the data to the disk file:

100 PRINT *TYPE RECORD NUMBER AND DATA"

105 INPUT R,D$

110 DOPEN#1,"FILE1",DO

120 GOSUB 190

130 REC0RD#1,(R)

140 GOSUB 190

150 PRINT#1,D$

160 GOSUB 190

170 DCL0SE#1

180 END

190 IF DS<20 THEN RETURN

200 PRINT DS$

220 STOP

Line 130 positions the file pointer to record number (R), specified by the user. Note that a variable used in the RECORD command must be enclosed in parentheses.

Line 150 causes the data stored in D$ to be stored on the disk.

The RECORD command may be omitted if the file is to be accessed sequentially, which saves time during program execution. An example of this occurs when writing a large data base to the disk file. Assume that the program has already dimensioned D$ as an array which contains 100 elements. These elements are to be written to the disk in records num ber 1 thru 100 of file FILEl. This could be accomplished with the following program segment:

110 DOPEN#1,"FILE1",DO

120 GOSUB 190

130 FOR 1=1 TO 100

150 PRINT#1,D$(I)

160 GOSUB 190

165 NEXT I

170 DCL0SE#1

180 END

190 IF DS<20 THEN RETURN

200 PRINT DS$

220 STOP

Since the record pointer is automatically set to record 1 when the file is opened, record 1 is the first record written. If no RECORD command is executed the DOS automatically posi tions to the next record after each PRINT. Therefore, the contents of D$ will be written to records 1 thru 100 of the file.

For detailed description of related BASIC commands, refer to chapter 4 of this manual and the BASIC 4.0 reference manual.

NOTES n n r -

Chapter

SIMPLIFYING THE USE OF

COMMODORE DISK-

RELATED COMMANDS

It has been explained that all disk commands must be preceded with the BASIC PRINT# command and enclosed in quotation marks. This is true, but your computer can be pro grammed to perform these tasks as well as how to load and run programs stored on diskette.

LOADING THE DOS SUPPORT PROGRAM

The first file on the TEST/DEMO diskette contains a program called UNIVERSAL

WEDGE, often referred to as DOS SUPPORT. This program, when loaded into memory, takes care of the tasks mentioned above. If your computer has Commodore BASIC 4.0 you can use the quick load procedure to load the DOS SUPPORT program. For those of you not equipped with BASIC 4.0, the following procedure will work:

Start with a cold start condition by resetting both the computer and disk drive and insert the TEST/DEMO disk in drive 0.

STEP 1; Type: L0AD"*",8 and press RETURN.

The screen displays:

STEP 2: Type: RUN and press RETURN.

^is will cai^ the DOS Support program to be executed. This program will re

locate Itself into the top of the user memory, where it will coexist with programs which are entered later. DOS support will not need to be reloaded until the com puter IS reset. The following special symbols, once implemented, will simplify the entry of disk commands.

USING THE DOS SUPPORT SYMBOLS: > AND ®

Once DOS SUPTORT is implemented, preceding dislc commands with PRINT#lfn or enclos-

ISo T ^ Trequired: precede the disk command with either

symbol ^y^bol (>) or the at-sign (@). The examples in this manual use the >

Examples: >10 is the same as PRINT#1,"I0"

>S0:FILE1 is the same as PRINT#15,"S0 ^J'lLEl"

The OPEN statement isNOT required before a statement.

^th 5 loaded

\^en you use the >symbol, the dkectory is printed directly to the screen, thusZSg

the data m the computer's memory.

pie!,ei:viiig

Examples: >$0 means display the entire directory of drive 0.

>$1:Q* means to display all the fUes on drive 1that begin with aQ.

Ki!SaTSUVetJSd:'"

To stop adirectory listmg and return to BASIC, press RUN/STOP.

The third use of > is the request of error messages.

Example: > jg equivalent to:

10 OPEN2,8,15

20 INPUT#2,A$,B$,C$,D$

30 PRINTA$,B$,C$,D$

LOADING A PROGRAM WITH THE /

Example: /ACCT loads the program ACCT into the computer's memory.

LOADING AND RUNNING A PROGRAM WITH UP ARROW

The up arrow (t) loads a program from a diskette and executes it. Both diskettes are searched if necessary.

Example: tJDATA loads and runs the program JDATA.

SPECIAL DOS SUPPORT INFORMATION

The DOS SUPPORT program has certain limitations. These are:

1. The program must be reaccessed from the disk whenever resetting the computer.

2. DOS Support may only be used when communicating with the disk in direct mode. That is, they may NOT be used in a program.

3. The disk directory may be printed on the printer by giving these commands:

LOAD "$0»,8

OPEN 4,4:CMD4:LIST

PRINT#4:CL0SE 4

NOTES

\ n

Chapter

ERROR MESSAGES-

PATTERN MATCHING

FILE NAMES-

DISK COMMANDS

REQUESTING ERROR MESSAGES: COMMODORE DISK DRIVES

The execution of the following program displays the error on the computer screen and resets the device error indicator:

CBM Series 2001

CBM Series 3000 with

BASIC 3.0

CBM Series 8000

CBM Series 4000 with

BASIC 4.0

where A=error message number B$=error message C=track D=sector

SUMMARY OF CBM FLOPPY ERROR MESSAGES

0 OK, no error exists.

1 Files scratched response. Not an error condition.

2-19 Unused error messages: should be ignored.

Block header not found on disk.

Sync character not found.

Data block not present.

Checksum error in data.

Byte decoding error.

Write-verify error.

Attempt to write with write protect on.

Checksum error in header.

Data extends into next block.

Disk id mismatch.

General syntax error.

Invalid command.

Long line.

Invalid filename.

No file given.

Command file not found.

Record not present.

Overflow in record.

File too large.

File open for write.

File not open.

File not found.

File exists.

File type mismatch.

No block.

Illegal track or sector.

Illegal system track or sector.

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. (8050 only)

DESCRIPTION OF DOS ERROR MESSAGES

NOTE: Error message numbers less than 20 should be ignored with the exception of 01

which gives information about the number of files scratched with the SCRATCH command.

20: READ ERROR (block header not found) piedisk controUer is unable to locate the header of the requested data block, byan illegal sector number, or the header has been destroyed.

21: READ ERROR (nosync character)

The disk controller is unable to detect async mark on the desired track. Caused by miMlignment of the read/write head, no diskette is present, or unformatted or impro perly seated diskette. Can also indicate a hardware failure.

22: READ ERROR (data block not present)

The disk controller has been requested to read or verify a data block that wasnot properly written. This error message occurs in conjunction 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 oneor more of the data bytes. The data has been read into the DOS memory, but the checksum 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, but a hardware error has been created due to an mvalid 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 data in the DOS memory.

26: WRITE PROTECT ON

This message isgenerated when the controller has been requested to write a data block while the write protectswitch is depressed. Typically, this is caused by using a diskette with a write 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. Thismessage may alsoindicate ground ing problems.

28: WRITE ERROR (long data block)

The controller attempts to detect the sync mark of the next header after writing a data block. If the sync mark does not appear within a pre-determined time, the error message is generated. The error is caused by a bad diskette format (the data extends into the next block), or by hardware failure.

29: DISK ID MISMATCH

This message is generated when the controller has been requested to access a diskette which has not been initialized. The message can also occur if a diskette has a bad header.

30: SYNTAX ERROR (general syntax)

The DOS cannot interpret the command sent to the command channel. Typically, this is caused by an illegal number of file names, or patterns areillegally 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 fUe name)

Pattern matching is invalidly used in the OPEN or SAVE command.

34: SYNTAX ERROR (no fUe given)

The file name was left out of a command 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 to a record beyond end of file in a relative file. If the intent is to expand the file by adding the new record (with a PRINT# com mand), the error message may be ignored. INPUT or GETshould not be attempted after this error is detected without furst repositioning.

51: OVERFLOW IN RECORD

PRINT# statement exceeds record boundary. Information is truncated. Since the car riage return which is sent as a record terminator is counted in the record size, this message will occur ifthe total characters in the record (including the final carriage return) exceeds the defined size.

52: FILE TOO LARGE

Record position within a relative file indicates that disk overflow will result.

60: WRITE FILE OPEN V/

This message is generated when a write file that has not been closed is being opened for reading.

61: FILE NOT OPEN

This message is generated when a file is being accessed that has not been opened in the

DOS. Sometimes, in this case, a message isnot generated; the request issimply ignored.

62: FILE NOT FOUND

The requested file does not exist on the indicated drive.

63: FILE EXISTS

The file name of the file being created already exists on the diskette.

64: FILE TYPE MISMATCH

The file type does not match thefile type inthe directory entry for therequested file.

65: NO BLOCK

This message occurs in conjunction with the B-A command. It indicates that the block to be allocated has been previously allocated. The parameters indicate the track and sector available with the next highest number. If the parameters are zero (0), then all blocks higher in number are in use.

66: ILLEGAL TRACK AND SECTOR

The DOS has attempted to accessa track or sector which does not exist in the format being used. This may indicate a problem reading the pointer to the next block.

67: ILLEGAL SYSTEM TORS

This special error message indicates an illegal system track or sector.

70: NO CHANNEL (avaUable)

The requested channel is not available, or all channels are in use. A maximum of five sequential files may be opened at one time to the DOS. Direct access channels may have six opened files.

71: DIR9ectory) ERROR

The BAM does not match the internal count. There is a problem 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 152 entries for the 2040,3040, and 4040 or 243 entries for the 8050. DISK FULL is sent when two blocks are available on the 8050 to allow the current file to be closed.

73: DOS MISMATCH (73, CBM DOS V2.5 8050)

(73,CBMDOSV2 ) for 4040

DOS 1 and 2 are read compatible but not write compatible. Disks may be interchange ably read with either DOS, but a disk formatted on one version cannot be written upon with the other version because the format is different. This error is displayed whenever an attempt is made to write upon a disk which has been formatted m a noncompatible format. (A utility routine is available to assist in converting from one for mat to another.) This message may also appear after power up.

74: DRIVE NOT READY

An attempt has been made to access the 8050 Dual Drive Floppy Disk without any diskettes present in either drive.

PATTERN MATCHING

Pattern matching of file names is available on all Commodore floppys. Pattern matching uses the question mark (?) and the asterisk (*) to perform operationson several files with simi lar names.

The asterisk is used at the end of a string of characters to indicate that the rest of the name is insignificant. For example:

FIL'*'

FIL could refer to files named or FILEl or FILEDATA or FILLER or any other file name starting with the letters FIL.

The question mark may be used anywhere within the strmg of characters to indicate that the character in that particular position should be disregarded. For example:

?????.SRC

TSTER.SRC

or DIAGN.SRC

or PROGR.SRC

could refer to files named but not SRC.FILES

Both the characters and the position of the characters are significant.

The question mark and asterisk may be combined in many ways:

*J??????

does not make sense becausethe question marks are in an area which is insignificant (be cause of the asterisk).

P???FIL*

PET FILE will access files with the names or PRGFILE-32 or POKEFILES$$ or any other files starting with P and having FIL in positions 5-7.

SCRATCH with pattern matching should be used carefully, since multiple files will be scratched. LOAD or DLOAD will load the first file which fits the pattern matchmg. OPEN or DOPEN with pattern matching may be used to openan existing file, in which case the first existing file encountered which fits the description will be opened. However, OPEN or

DOPEN should not be used with pattern matching when creating a new fUe. Never use

RENAME, SAVE, DSAVE, or COPY for pattern matching since an error condition will result, if attempted.

USER'S QUICK REFERENCE: DISK COMMANDS

The user's quick reference guide will assist the user in becoming familiar with the various commands used in both BASIC 3.0 and BASIC 4.0, and with the DOS SUPPORT utility as well as with all Commodore disk units.

In order to make BASIC 4.0easier to use, disk commands have been incorporated into the language. For example, with BASIC 4.0:

• DSAVE and DLOAD commands eliminate the need to specify device number each time you store and retrieve disk files.

• Directory display is now a one-step procedure and no longer interferes with the program in memory.

• It is no longer necessary to write a program to read the error channel. The variable

DS$ contains the error message.

• Formatting is now a one-step procedure through the use of HEADER command.

Commands in BASIC 3.0are upward compatible with BASIC 4.0.Thatis, if you are familiar with BASIC 3.0, those commands will still work on the Series 8000 Computer furnished with BASIC 4.0. Alldisk commands available on the 2040 are upward compatible with both the 4040 and 8050.

Table 17. User's Quick Reference—Disk Commands

BASIC 3.0

SAVE "dr:fn",8

UNIVERSAL

DOS SUPPORT

SAVE"dr:fii",8

BASIC 4.0

DSAVE,**fn",Ddr

(drive defaults to 0)

DLOAD"fn",Ddr

(drive defaults to 0)

LOAD"dr:fh",8 /dr:fn

(searches both drives)

LOAD"*",8

RUN tdr:fn DLOAD"fn",Ddr

RUN

LOAD"dr:fn",8 t* shifted RUN/STOP

LOAD"$0",8

UST

(destroys memory)

>$0

(preserves memory)

DIRECTORY or

DKshifted R>

(preserves memory)

10 0PEN1,8,15

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

30 printa,b$,c,d

> return ?DS$ or ?DS

(DS is number of error only)

NOTE: Assume that 0PEN1,8,15 has already been typed for all of the PRINT# com mands in the following formats. Commands may be spelled out or abbreviated by the ^ t letter as illustrated.

INITLIALIZE

PRINT#l,"Ix" PRINT#l,"Ix" >Ix

VALIDATE

PRINT#!,"Vdr" >Vdr COLLECT Ddr

SCRATCH

PRINT#l,"Sdr:fn" >dr:fn SCRATCH"fn",Ddr

DUPLICATE

PRINT#l,"Dddr=sdr" BACKUP Dsdr TO Dddr

PRINT#1 ,"Cddr=sdr"

PRINT#l,"Cdr:dfn= dr:sfn"

>Dddr=sdr

COPY (aU disk)

>Cddr=sdr

COPY (single file)

>Cdr:dfn=dr:sfn

COPY Dsdr TO Dddr

COPY Ddr,"8fn"TO

Ddr,"dfn»'

PRINT#l,"Cdr:dfh= dr:sfnl,dr:sfn2,...

CONCATENATE FILES

>Cdr:dfn=dr:8fl, dr:sfh2,...

CONCAT Ddr,"sfn" TO

Ddr,"dfn"

RENAME FILES

PRINT#l,"Rdr:dfn=sfn" >Rdr:dfn=sfn" RENAME Ddr,"sfn" TO

"dfn"

PRINT#1 ,"Ndr :dnamepcx"

FORMAT A DISKETTE

>Ndr:dname,xx HEADER "dname",Ddr.Ixx

NOTES

Chapter

RANDOM 1.00

PROGRAM LISTING

This chapter provides a complete listing of the random access program described in Chapter

6 under the heading of Random Access Example.

REflDV.

1 REM RRNDOtI 1.0

2 REM SUBROUTINES TO MflNflGE RANDOM ACCESS FILES

3 REM VRRIflBLES ARE SET FROM DATA OF DESCRIPTOR FILE & KEV LIST FILES...

4 REM ...DEFINED BV USER PROGRAM

5 REM VARIABLES SHOULD REFLECT DESIRED FILE STRUCTURE

6 REM ALL FUNCTIONS ACT UPON THE VARIABLES DEFINED BELOW l e REM

11 REM

#***#*#*♦#*************#*

12 REM

13 POKE1022,128:REM TURN DOS SUPPORT 3.1 OFF

15 M$=CHR$:<13>:REM FIELD MARKER

16 SP$=" "+"":REM SPACE FOR PADDING

20 C0=2:

21 Cl=3:

25 CC=15:

30 D=0:

31 T=0:

32 S=0:

REM DIRECT CHANNEL

REM SEQUENTIAL CHANNEL

REM COMMAND CHANNEL

REM CURRENT DRIVE #

REM CURRENT TRACK #

REM CURRENT SECTOR #

35 DD=0: REM DESCRIPTOR DRIVE #

36 RD=0:

40 ID$="":

45 NR=0:

46 CR=0:

47 FR=0:

50 NF=0:

51 CF=0:

REM RANDOM DRIVE #

REM RANDOM DISK ID

REM # RECORDS IN R-FILE

REM CURRENT RECORD #

REM 1ST FREE RECORD UNUSED

REM # FIELDS IN RECORD

REM CURRENT FIELD #

55 RB=0:

56 RS=0:

60 NB=0:

65 E=0:

REM # RECORDS PER BLOCK

REM RECORD SIZE IN BYTES

REM # BLOCKS IN R-FILE

REM ERROR FLAG, OK =0

66 REM EN$,EM$,ET$,ES$,ET,ES ERROR CHANNEL VARIABLES^

70 EP=.5/256= REM INTEGER CORRECTION

75 RS=0: REM INDEX ARRAV ADDRESSING STRATEGY

76 REM AS=0: USE ARRAV INDEX; AS=1: T&S ARE SET, CR= RECORD OFFSET IN BLOCK

90 REM "A" VARIABLES ARE TEMPORARY

95 DN=8:0PENCC,DN,CC: REM DN= DEVICE NUMBER

98 GOTO2000: REM START OF USER PROGRAM

99 REM

2:flLPHa

UPDATE

1:NUMERIC.

KEV

FIELDREAD

SINGLEFIELD

ARGS-fiLPHfi.BINfiRV

LISTPER

FIELD-flRGS-NUMERIC

VALUE

ARRfiV

ARRAV

ROUTINE

RECORD

POSITION

CR,SINGLE

0=BINflRV.

CFS^<I-0]

HERDING

RECORDCR,

PRINT#CC,"B-P:"C0;FPX<CF)+RP

KEV

INDEX

SIZE

PRINT#CC,"B-P:"C0;FP?i<CF)+RP

SET IS B-P

FIELD

PRIMARV

FIELD

SECTOR

TRACK

FIELD

=REMRELATIVE

:REM

:REMFIELD

:REM

PRINT#C0,A$;M$;

IFFTJi<CF)OlTHEN520

FIELD<CF>,

READ

GOSUB1000:IFETHEN1900

PRINT#CC,"U1:"C0;D;T;S

O"""ECORD

GOSUB1000:IFETHEN1900

PRINT#CC,"U2:"C0;D;T;S

UPDATE

GOSUB1000:IFETHEN1900

PRINT#CC."U1:"C0;D;TJS

FIELD(CF)OF

GOSUB1000:IFETHEN1900

PRINT#CC,"U1:"C0;D;T;S

PRINT#CC,"B-P:"C0;RP

CR RECORD,

PRINT#CC,"U2:"C0;D;TjS

GOSUB1000:IFETHEN1900

PRINT#CC,"U1•"C0;d;T;s

PRINT#CC,"B-P:"C0;RP

CR RECORD,

IFIT?i=-lTHENRETURN

FIELD

FP?i<I>=SUM

NB & NF

DIMENSION

NR.

FILE

SET

IFFPJi=-lTHENRETURN

:REM

IS?i<NB).:REM

K1$<NR)

FS?iCNF)

IT?i(NB)

F0RCF=1T0NF

RETURN

FORCFslTONF

F^CNF)

UPDATE

F<NF)

UPDATE

1ST

RfiNDOM

GOSUB150

GOSUB900

GOSUB500

READ

GOSUB900

GOSUB600

GOSUB900

GOSUB500

GOSUB900

GOSUB600

RETURN

IT?i=-l

NEXTCF

RETURN

NEXTCF

RETURN

REM

DIM

DIMFH$CNF> 2

DIM

DIMFP?S<NF)

DIM

REM

RETURN

FP;i=-l

REM

502

501

510

470

465

480

475

460

500

455

452rIm

425

420

415

430

410

440

435

405

402REM

450

165

160

155

151

150

135 }|?S

140

146

145

110

105

120

115

111

;25

102

101

103

100

302

301

305

315

310

320

325

300

245

205

202

210

215

225

220

230

201

200

240

235

175 litSiC

400

340

335

330

REM

535

530

' ^

600 REM

601 REM READ FIELD<CF).

B-P IS SET

602 REtl

610 IF FT?i<CF) THEN645

615 fll$=""

620 FORJ=lTOFSJi<CF)

625 GET#C0,fl$:lFfl$=""THENfl4:-CHR$<0)

630 fll$=fll4:+fl$

635 NEXT:F$<CF)=flU

640 GET#C0.flf:RETURN

645 INPUT#C0.F$(:CF>

650 IFFTX(;CF)01THEN RETURN

655 F<CF>=VflL<:F$<CF>): RETURN

700 REM

701 REM ALLOCflTE ONE BLOCK. T & S =REQUESTED TRRCK SECTOR

702 REM RETURNED T & S fiRE RLLOCflTED VALUES <T=18 IS SKIPPED)

703 REM

710 GOSUB800:IFETHEN1900: REM CHECK T S

715 PRINT#CC."B-fl:"D;T;S

720 INPUT#CC/EN.EMf.ET/ES

725 IFEN=0THENRETURN

730 IFENO65THEN1900

735 I FET= 1 STHENTs 19: S=0 60T0715

736 T=ET:S=ES

740 G0T0715

750 REM

751 REM FREE ONE BLOCK.

T S = TRACK & SECTOR

752 REM

760 GOSUB800:IFETHEN1900: REM CHECK T & S

770 PRINT#CC."B-F:"DjT;S

780 INPUT#CC.EN.EM$,ET.ES

785 IFEN=0THENRETURN

790 GOTO1900

800 REM mmmmmmmmmmmm-*

801 REM CHECK MAX SECTOR

802 REM

810 IFT>35THEN1900

820 E=0:1FT=0THEN=40 =GOTO1900

840 A3=16:IFT>30THEN880

850 A3=17:IFT>24THEN880

860 A3=19:IFT>17THEN880

870 R3=20

880 IFS>A3THEN1900

890 RETURN

900 REM

901 REM SET RECORD'S TRACK. SECTOR RECORD POINTER FROM INDEX ARRAVS

902 REM

905 D=RD

910 E=0

915 1 FRS=-1 THENRP=CRitiRS+1: GOTO950

920 RP=INT<<CR-1)/'RB+EP):IFRP>NB OR RP<0THENEN=41 =GOTO 1900

930 T=IT?i<:RP>:S=IS:i<RP>

940 RP=INT<<<CR-1VRB-RP+EP)*RS*RB)+1

950 IFRP>254THEN EN=41:GOTO1900

960 RETURN

1000 REM

1001 REM INPUT 2040 ERROR STATUS

1002 REM

1005 INPUT#CC.EN$.EM$.ET.ES

1010 EN=VAL<EN$):E=0

1015 IF EN$="00" THEN RETURN

1017 ET$=STR$ <ET):ESf-STR$ <ES)

1020 I FEN^OR I GHT$ <" 0 " +MID$ <STR<:<EN>. 2 >. 2 >THEN1070

1030 IF EN=1 THEN EM$= EJ$+" "+EM$: RETURN

1035 E=E+1

1040 EM$="a"+EN$+"5 "+EM$

1050 IF EN<30 OR EN=65 THEN EM4:=EM#+" ON "+ET$+".

"+ES$

1060 RETURN

1070 EM$="aBVSTEM NOT RESPONDING PROPERLV"

1080 EM$=EM$+EN$+EN$+ET$+ES$

1085 E=E+1

1090 RETURN

1100 REM

1101 REM CREATE DESCRIPTOR FILE

1102 REM input: F$= FILENAME

1103 REM

1104 REM

ID$>NR.NF/FS?J<>,FT;i<).FH$<)

DD=^DESCRIPTOR FILE DRIVE #

1105 REM RD= RANDOM DISK DRIVE #

1106 REM DRIVES MUST BE INITIALIZED

1109 REM

1110 RS=l:D=RD

1115 FORA0= 1TONF: FP^i <A0 ) =RS: RS=FSfi <A0 >+RS+1: NEXT: RS=RS-1

1116 RB=INT<254/RS+EP>

1120 OPENC0/DN/C0."#":GOSUB1000:IFETHEN1900

1121 GOSUB1280 s

1122 PRINT#CC."B-P:"C0;l

1123 FORA0=1TORE:F0RR1=1TONF

1124 PRINT#C0.LEFT$<SP$,FS?i<A1 > ) ; ;

1126 NEXTR1.A0

1130 NB=INT <NR/RB+EP):IF <NR/RB-NB)*RB>=1THENNB=NB+1

1135 T=l:S=0:GOSUB150

1140 FORA0=0TONB-1-GOSUB710:IFETHEN1900

1145 IT?i<:R0)=T:IS?i<fl0>=S:GOSUB430:NEXT

1150 GOSUB710

1152 PRINT#CC,"B-P:"C0;1

1155 PRINT#C0,NR;M$;1;M$;nb;m$;rs;M$;RB;M$;NF;M$;

1160 print#cc,"b-w:"C0;d;t;s

1165 Af=STR$<DD>+":"+LEFT#<F$+SP4:/10)+".DESCR.U.W"

1166 OPENCl.DN.Cl.RI:

1167 GOSUB1000:IFETHEN1900

1168 PRINT#C1. ID$;M^;T;M$;S;M$;

1170 FORA0=1TONF: PRINT#C1 >CHR$(FS;i<A0)>; CHR$<FT;i<A0> ); FHf<A0>;M$; =NEXT

1175 FORA0=0TONB-l:PRINT#Cl.CHR$<IT?i<:A0>);CHR$(IS?i<A0>>; :NEXT

1180 CLOSECl:CLOSEC0:RETURN

1200 REM

1201 REM OPEN RELATIVE FILE

1202 REM INPUT: F$= FILENAME

1203 REM DD= DESCRIPTOR FILE DRIVE #

1204 REM RD= RANDOM DISK DRIVE #

1205 REM DRIVES MUST BE INITIALIZED

1209 REM

1210 flf=STR$(DD>+":"+LEFTf<F$+SP«:.10)+".DESCR.U.R"

1215 OPENC1.DN.C1.R$:GOSUB1000:IFETHEN1900

1220 INPUT#C1.ID^,T,S

1225 OPENC0,DH,C0.GOSUB1000:IFETHEN1900

1226 GOSUB1280

1227 PRINT#CC/"B-R:";C0;RD;T;S:GOSUB1000:IFETHEN1900

1230 INPUT#C0.HR.FR,NB.RS/RB.NF

1235 GOSUB100:FT?i<0)=T:FS;i<0>=S

1240 FORR0=1TONF:GOSUB1298:FSX<R0)=RSC< A$)

1245 GOSUB1298: FT?i CA0>^ASC< R$ >

1250 INPUT#C1,FH$<A0>:NEXT

1255 FORA0=0TONB-l:GOSUB1298:IT?i<A0>=ASC<A$>

1260 GOSUB1298:1S?i<A0)=ASC<A$>: NEXT

1265 GOSUB1000:IFETHEN1900

1270 CLOSECl

1275 RETURN

1280 PRINTftCC/ "ur- ";C0;RD; 'M8.0" : GOSUB1000:1FETHEN1900

1285 PRINT#CC."B-P:";C0;162

2iI*i®''^^'^l^"f^^=f'^+fil^ =IFID^<>fl^THENEN=43:EM$a"WRONG RAND DISK" :GOTO1900

RcTURN

1298 GET#Cl.A$:IFfl$=""THENA$=CHR$<0>

1299 RETURN

1400 REM

1401 REM CLOSE RELATIVE FILE

1402 REM INPUT: VARIABLES FROM OPEN SHOULD BE VALID

1409 REM

1410 PRINT#CC."E-P:"C0;1

1420 PRINT#C0.nr;m$;FR;m$;NB;M«:;R5;m$;rb;m$;NF;m$;

1430 PRINT#CC."B-W:"C0;D;FT?i<0);FS?i<0)

1440 CLOSEC0

1490 RETURN

1900 E=E+l:RETURN

' ^

= NEXT I>+RS+1 RS=FS?i<

ADDED"

ID$=LEFT$<:iD$.2)

IFLEFT$<R$,1)O"V"THEN2100

ADD";A$:IFLEFT$<A$>1)O"V"THEN2160

1)O"V"THEN2220

<I))=NEXT

>= <I

MAV RECORDS

ADDITIONAL

3.1

SUPPORT

NO FULL,

TURNDOS

IS FILE

FILE RRND CLOSE

< F$ <I):F<I)=VAL PRINTFH$<I>;:INPUTF$ mmm"

RECORD

PRESENT"

WISH

NOT

ADD

VOU

F$+SP$,10)+".KEV01>U"

FIELD";A

ACCESS^"

TVPE"

2=flLPHflW"

>,FT/i <I >FS?i

1=HUMERIC.

SIZE.FIELD

NPUTFH$<

>10>+".KEV01.U,W"

<I)=NEXT:PRINT

= GOTO2300

GOTO2160

RECORD)" random

= NEXT I> RR?i<

VOU"

<I), K1$

ADD TO

QUITW" liirSRR*

IMI";A$:IFLEFT$<A$,

NUMBER";RD

NUMBER";DD

NRME";F$

ACCESS FOR

DRIVE

<F$+SP$ ="+LEFT$

FILE

DRIVE

DD)+":"+LEFT$<

:I ";I.

RECORD

NfiME.FIELD

RECORD";NF PER

-JMII";ID$: DISK

NUMBER";RD

NUMBER";DD

NRME";Ff

FILE fl CREftTE TO

DRIVE

RANDOM

FILE

<DD>+"

RECORDS";NR

0=BINflRV.

FIELDS

FIELD

FIELD NT" PRI

TVPES:

DRIVE

WISH

FILE

VOU

INPUT

FILE

SEE

TO //

INPUT#4,

RETURN

"THEN2310

GOSUB300

MODS

FILE

RANDOM

"F4:(A>:PRINT"n";:INPUTF$(fl):F<A>=VAL<F$<A>)

11>:

OPEN

=1TONF: FORI

RS=0

PRINT"

PRINT"W

GOSUB110

INPUT"flNV

INPUT"WHICH

INPUT"WISH

IFRR$="

IFRR$="/'/"THEN2400

IFRR$="/DIR"THENGOSUB4000=

FF=0

INPUT#4,RR:IFRR=0THEN2147

FOR11=1TORR:IFK1$<11)ORR$THENNEXT

CR=RR*^<

FORI=1TONF:PRINTI;")"FH$<I>":".F$

INPUT")iRANDOM

INPUT"KEV

INPUT"RANDOM

FORI=ITORR:

CL0SE4

PRINT":i»$ffili»iii»i»niiiiBAMPLE

PRINT"TVPE

PRINT"<HIT

PRINT")!WIJH0SE

PRINT"

INPUT"RftNDOM

INPUT"ENTER

INPUT"NUMBER

0PEH4>8.4,STR$

PRINT#4,0;M$;:CL0SE4

REM

GOSUB1200:IFETHEN3300

0PEN4,8,4,STR$C

INPUT-nSfilDO

INPUT"WRflNDOM

IHPUT"KEV fl$="I":IFDD=RDTHENflf="I"+STR$<DD>

PRINTttCC.fl^

GOSUB1100:IFETHEN3300

GOTO2120

FF=l:GOTO2190

IFFF=0THEN2160

IFA=1THENK1$<ID=F$<A>

GOSUB200

IFFR>NRTHEN2500

INPUT"DO

FORI=1TONF=

GOTO2160

PRINT"^RECORD

PRINT")S»###

CR=FR-FR=FR+1:RR=RR+1

GOSUB200

Kl$<RR)=F$<l):RR/i<RR)=CR

GOTO2160

REM

GOSUB1400

GOSUB1000:IFETHEN3900 print#4,rr;m$;

F0RI=lT0RR:PRINT#4,Kl$<n;M$;RR:«I>;M#;:NEXT

GOSUB1000:IFETHEN3900

CL0SE4

PRINT"THE

GOSUB1000:IFETHEN3900

POKE1022,8:END:REM

GOTO2160

PRINTE,EM$:STOP

FORDI=0TONR:PRINTKU<DI>:next:RETURN

0PEN4,8,4>"e"+STR$<DD>+":"+LEFTf<F$+SP$,10>+".KEV01.U,W"

2220

2210

2222

2225

2200

2195

2190

2300

2230

2312

2310

2305

2320

2315

2330

2165

2161

2167

2160

2156

2142

2140

2145

2155

2150

2147

2110

2105

2120

2103

2100

2170

2168

2180

2175

2185

2055

2050

2090

2020

2019

2030

2025

2040

2015

2010

2016

2007

2006

2002

2001

2000

2005

2003

2405

2400

2350

2340

2420

2410

2455

2450

2440

2430

2445

4000

3900

2500

2490

2510

^ ^

NOTES

' '' • i •;* •

•• :

. " ' ' • \

• "

• • .

•

'' " ' ".i i''

• ' ^- . ' : -

•L i;;-;

• -• i;,'-

• • '

• .<• •

• • • • • • •'

• • , '••

.>•: ' •'. •• • • •• •••

^ •. rn:-^

^'^v-vv

:S^::

- • • • V -

• •

" • V '• -

' •

• i m'-:--r

••'•• =

•, , < ' w ' •'•• •" • ir-iiA;- ••••V

• ; •. .

• wt'r;, ; i-;:;

"fv

•I '

•••" T -

•

• •- •" !

v - v

...

;•: :-

•v.

..-r • . . .

..r.

• • ^ ' V• J

• ;v • , ••; ri

• •• v .;

-iO'-;,:-

Chapter

INDEX

AC power cord, 3

Advanced disk programming, 47

Advanced file handling, 65

At symbol (see DOS Support)

BACKUP (BASIC 4.0 direct command), 29

BAM, 22,47

Format

2040,3040, 55

4040,56

8050,58

Memory requirements, 22

BASIC commands

CLOSE command, 39

DCLOSE command, 40

DLOAD command, 36

DOPEN command, 39

DSAVE command, 36

GET# command, 43

INPUT# command, 42

LOAD command, 36

OPEN command, 38

PRINT# command, 41

RECORD# command, 43

SAVE command, 36

VERIFY command, 37

BASIC commands, disk drive, 35

BASIC 4.0 direct commands

BACKUP command, 29

COLLECT command, 28

CONCAT command, 31

COPY command, 31

RENAME command, 32

SCRATCH command, 33

Block availability map, 22

Block distribution, by track, 54

BLOCK-ALLOCATE command, 51

BLOCK-EXECUTE command, 50

BLOCK-READ command, 49

BLOCK-WRITE command, 50

Block pointer, 26

Buffer number, 65

BUFFER-POINTER command, 50

Business keyboard, 14,17

Bus, IEEE, 12

Cables, 11

PET to IEEE, 11

IEEE to IEEE, 11,

CHR$ function, 41,42,48,49,51, 52

CLOSE command, 39

Closing the command channel, 40

Closing the data channel, 41

COLLECT (BASIC 4.0 direct command), 28

Command channel, 40

Compatability

BASIC versions, 35

Disk drives with computers, 3

Series 2001, 3

Series 3000, 3

Series 8000,3

DOS versions, 69

CONCAT (BASIC 4.0 direct command), 31

COPY (BASIC 4.0 direct command), 31

COPY command, 31

Data blocks, 69

Data channel

Closing, 41

Data file

Concatenation, 29,30

Copying, 29

Renaming, 31

Data handling, 35

BASIC commands for, 35

DCLOSE command, 40

DEMO diskette (see TEST/DEMO diskette)

Description of DOS error messages, 81

Descriptor (.DESC), 66

Device number, 35

Diagnostic boot, 18

Direct access, 65

Special OPEN and CLOSE statements,

Directory, 26

Loading, 26

Printing, 27

DIRECTORY (BASIC 4.0 direct command), 27

Directory format, 60

Directory header

2040,3040,55

4040,56

Directory header block, 8050,57

Diskettes

Care of, 9

Inserting diskettes

2040,3040,4040,13

8050,13

Disk maintenance commands, 23

BACKUP (BASIC 4.0 direct command),

COLLECT (BASIC 4.0 direct conunand),

COPY (BASIC 4.0 direct command), 31

COPY command, 29

CONCAT (BASIC 4.0 direct command),

DIRECTORY (BASIC 4.0 direct com mand, 27

DUPLICATE command, 28

Limitations due to formats, 28

HEADER (BASIC 4.0 direct command),

NEW command, 24

VALIDATE command, 28

RENAME (BASIC 4.0 direct command),

RENAME command, 31

SCRATCH (BASIC 4.0 direct com- ; mand), 33

SCRATCH command, 32

Disk maintenance commands

Diskette level, 23

File level, 23

Disk operating system, 15,18,22,25,47,

59,69,70,71,72,77

Disk programming, advanced, 47

Disk utility command set, 48

BLOCK-READ, 48,50

BLOCK-WRITE, 48, 50

BLOCK-EXECUTE, 48, 50

BUFFER-POINTER, 48, 50

BLOCK-ALLOCATE, 48,51

MEMORY, 51 ^

Memory-Write, 48,51

Memory-Read, 48,52

Memory-Execute, 48, 52

USER, 48,52

Disk zones, 59

DLOAD command, 36

DOPEN command, 39

DOS, 15,18,22,25,47,59,69,70,71,

72,77

DOS support, 22, 77

Loading DOS support, 15,18,77

Loading a program, 14,17, 78

Loading and running a program, l&i, 18,78

Special DOS support, 79

Using DOS symbols > and @, 78 \

Limitations, 79

Disk backup, 15,18,66

Disk drive

Care of, 9

Description, 3

Front panel, 3

Back panel, 3

Interior configuration, 4

Connecting to computer, 11

Power-on test, 12

Performance tests, 14,17

Specifications, disk drives, 5,6,7,8

Unpacking, 9

Disk ID, 24,25,26

DSAVE command, 35

EOI signal, 71

Error messages, 81

Description of DOS error messages,82

Requesting error messages, 81

Summary of error messages, 82

Expanded view, single sector

2040 format, 62

8050 format, 63

Field fitting, 66

File format, program, 61

File handling, advanced, 65>

File pointer, 43

Floppy disk hookup, 11 ,

Format

BAM

2040,3040,55

4040.56

8050.57

Directory, 60

2040,3040, 55

4040.56

8050.57

Formatting, 24,25

GET# command, 41

HEADER (BASIC 4.0 direct command), 25

High byte, 48, 51

Hookup, floppy disk, 11

ID, 24,25,26

IEEE-488 interface, 4,11,47

Indicator lights (see LED indicator lights)

INPUT# command, 42

I/O channels, 22,47, 71

Inserting diskettes

2040,3040,4040,13

8050,13

Initialization

2040 and 3040,25

4040,26

8050,26

Job queue, 47

Key file, primary (see primary key file)

LED (light emitting diode; see LED indicator lights)

LED indicator lights, 3,12,18,81

Limitations, DUPLICATE command, 28

Line feed, suppression of, 41

LOAD$ command, 26

DOS support, 77 a program with a slash (/) symbol, 78 and running a program with up arrow

(t) symbol, 79

Low byte, 48, 51

Magnetic fields, 9

Maintenance commands, disk, 23

MEMORY commands, 51

MEMORY-WRITE command, 51

MEMORY-READ command, 52

MEMORY-EXECUTE command, 52

OPEN command, 38

Operating system, disk, 15,18,22, 25,47,

59,69, 70,71, 72,77

Parameters, 48,49

Parms, 48

Pattern matching, 85

Performance test

4040/8050,14

2040/3040,17

POKE command, 14,17

Pointer, block, 26

PRGfile, 36,61

Primary key file (.KEYOl), 66

PRINT# command, 41

Program file, 61

Program file format, 61

Quickload feature, 44

Quick reference: commands, 86

Random access

Add a record, 67

Change a record, 68

Create a file, 66

Ending the program, 69

Example, 66

Field markers, 66

Field size, 66

Restrictions, 66

Getting directory of listings, 69

Primary file names, 66

Primary key file, 66

Record size, 66

See a record, 68

Reading list, 4

RECORD# command, 43

Record pointer, 43

Relative files, 69

4040,8050, 69

Accessing, 73

Block pointers, 70

Channel restrictions, 71

Creating, 72

DOS compatability, 69

Expanding a file, 70

Format, 70

Main components, 69

Record size, 69

Side sectors, 69

Side tracks, 69

Storage capacity, 70

RENAME (BASIC 4.0 direct command),

RENAME command, 32

Requesting error messages, 81

Safety feature, HEADER command, 25

SAVE command, 36

SCRATCH (BASIC 4.0 direct command),

SCRATCH command, 33

Screen displays, actual, 14,15,16,17,18,

19,26, 37,40,44,45, 77,81

Secondary address, 35, 38,42,47, 50

Sector, single: expanded view, 70

Sequential format, 61

Side sectors, 69

Side track, 69

Simplifying commands, 77

Single record access, 65

Single sector, expanded view, 70

Slash (/) symbol (see DOS support)

Spanning, 71

Specifications

8050,6

2040/3040, 7

4040,8

Standard jump table, 53

Summary

^ ^

BASIC commands, data handling, 35

Disk commands, 86

Disk maintenance commands, 23

Disk utility commands, 48

Error messages, 81

Suppression of line feeds, 41

Symbols, DOS support, 78

Tab, write protect, 13

Tape to disk, 45

TEST/DEMO diskettes, 9,14,17, 23

U1 command, 52

U2 command, 52

Universal wedge, 23,77

Up arrow (t) symbol (see DOS support)

USER command, 52 '

User*s quick reference: disk commands, 86

Utility commands, disk, 48

VALIDATE command, 28

VERIFY command, 37

Wedge (>) symbol (see DOS support)

Write protect tab, 13

98 n

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