c64 Programmers Reference Guide 00 Toc Introduction

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FIRST EDITIONTHIRD PRINTING-1983

Copyright @ 1982 by Commodore Business Machines, Inc.All rights reserved.This manual is copyrighted and contains proprietary information. No part of this publica-tion may be reproduced, stored in a retrieval system, or transmitted in any form or by anymeans, eledronic, mechanical, photocopying, recording, or otherwise, without the priorwritten permission of COMMODORE BUSINESS MACHINES, Inc.

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TABLE OF CONTENTSINTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix. What's Included? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x. How to Use This Reference Gu ide . . . . . . . . . . . . . . . . . . . . " xi. Commodore 64 ApplicationsGuide. . . . . . . . . . . . . . . . . . . .. xii. Commodore Information Network. . . . . . . . . . . . . . . . . . . . . .. xvii1. BASIC PROGRAMMING RULES 1. Introduction 2. ScreenDisplay Codes (BASIC Character Set) ............. 2The Operating System(OS) 2. Programming Numbers and Variables 4

Integer, Floating-Point and String Constants.. . . . . . . . . . 4Integer, Floating-Point and String Variables. . . . . . . . . . . 7Integer, Floating-Point and String Arrays 8. Expressionsnd Operators. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Arithmetic Expressions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Arithmetic Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Relational Operators 12Logical Operators .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ~3Hierarchy of Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Stri ng Operations 16String Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17. Programming Techniques 18Data Conversions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Using the INPUT Statement 18Using the GETStatement. . . . . . . . . . . . . . . . . . . . . . . . . .. 22How to Crunch BASIC Programs 24

2. BASIC LANGUAGE VOCABULARY... . . . . . . . . . . . . . . . 29. Introduction 30. BASIC Keywords, Abbreviations, and Function Types 31. Description of BASIC Keywords (Alphabetical) 35. The Commodore 64 Keyboard and Features 93. Screen Editor.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 94iii


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3. PROGRAMMING GRAPHICS ON THECOMMODORE64 ... 99 Graphics Overview 100

Character Display Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . 100Bit Map Modes 100Sprites 100 GraphicsLocations 101VideoBankSelection.. . . . . . .. ... . . ... . .. . . ... . .. .. 101Screen Memory 102ColorMemory .1.. . . .. . . .. . . .. 103Character Memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 103. Standard CharacterMode. . . . . . . . . . . . . . . . . . . . . . . . . . .. 107Character Definitions 107 Programmable Characters 108. Multi-Color Mode Graphics 115Multi-Color Mode Bit 115. Extended Background Color Mode 120. BitMappedGraphics.. . ... . ... ... . . . .. . . ... . '" . ... 121Standard High-Resolution Bit Map Mode. . ... . ... . 122HowItWorks. . . .. . . ... ... . ... . . .. . . . . . . ... . .. 122

. Multi-ColorBitMap Mode. . .. . .. . . . . . . . . . . .. . . .. . . ... 127. SmoothScrolling 128. Sprites 131Defining a Sprite 131Sprite Poi nters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133Turning Sprites On 134Turning Sprites Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 135Co l o r s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135Multi-Color Mode 135Setting a Sprite to Multi-ColorMode. . . . . . .. . . ... . ... 136Expanded Sprites 136Sprite Positioning 137Sprite PositioningSummary. . . . . . . . . . . . . . . . . . . . . . . .. 143SpriteDisplayPriorities.. . . . . . . . . . . . . . . . . . . . . . . . . .. 144Collision Detects 144. Other Graphics Features 150Screen Blanking 150Raster Reg ister . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150Interrupt Status Register. . . . . . . . . . . . . . . . . . . . . . . . . . .. 151Suggested Screen and Character Color Combinations... 152

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. Programming Sprites-Another Look 153Making Sprites in BASIC-A Short Program. ... . .. . . .. 153Crunching Your Sprite Programs 156Positioning Sprites on the Screen 157Sprite Priorities .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 161Drawing a Sprite 162Creati ng a Sprite . . . Step by Step 163MovingYourSprite on the Screen. . .. . . .. . . .. . ... . . .. 165Ver t i ca lSc ro l l i ng . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166The Dancing Mouse-A Sprite Program Example. . . . . .. 166EasySpritemakingChart.. . ... . ... . . .. . ... . . ... 176SpritemakingNotes. . . .. . . .. . ... . . .. . . .. . . .. . ... . .. 177

4. PROGRAMMING SOUND AND MUSICON YOUR COMMODORE 64 183. Introduction 184

Volume Control 186Frequencies of Sound Waves. . . . . . . . . . . . . . . . . . . . . . . . 186. UsingMultipleVoices... . .. . . ... . . .. . . ... . .. . 187Controlling Multiple Voices 191

. Changing Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192UnderstandingWaveforms.... . ... . . . .. . ... 194. The EnvelopeGenerator. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 196. Filtering 199. Advanced Techniques. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 202. Synchronization and Ring Modulation 2075. BASICTOMACHINELANGUAGE 209. What is Machine Language? . .. . .. . . ... . . .. . . ... ... . .. 210What Does Machine Code Look Like? . . . . . . . . . . . . . . . . . 211

Simple Memory Map of the Commodore 64 . . . . . . . . . . . . 212The Registers Inside the 6510 Microprocessor 213. How Do You Write Machine Language Programs? 21464MON 215. Hexadecimalotation.. ... . .. . . .. . . . . . . . .. . ... .. 215Your First Machine Language Instruction 218Writing Your First Program 220. Addressing Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 221Zero Page 221The Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 222

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. Indexing 223Indirect Indexed 223Indexed Indirect 224Branches and Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 226

. Subroutines 228. Useful Tips for the Beginner 229. Approaching a Large Task. . . . . . . . . . . . . . . . . . . . . . . . . . .. 230. MCS6510 Microprocessor Instruction Set-Alphabetic Sequence "'. . . . . . . . . . . . . . . . . . . . . . . . .. 232Instruction Addressing Modes andRelated ExecutionTimes. . . . . . . . . . . . . . . . . . . . . . . . .. 254. Memory Management on the Commodore 64 . . . . . . . . . . . . . 260. The KERNAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 268. KERNALPower-Up Activities. . . . . . . . . . . . . . . . . . . . . . . . . .. 269How to Use the KERNAL. . . . . . . . . . . . . . . . . . . . . . . . . .. 270User Callable KERNALRoutines 272Error Codes 306. Using Machine Language From BASIC 307Where to Put Machine Language Routines.. . . . . . . . . . .. 309How to Enter Machine Language 309. Commodore 64 MemoryMap ... . . . .. . ... .. 310Commodore 64 Input/Output Assignments. . . . . . . . . . . . .. 320

6. INPUT/OUTPUT GUIDE... . . . . . . . . . . . . . . . . . . . . . . . . . .. 335. Introduction 336. Output to the TV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336. Output to Other Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 337Output to Printer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 338Output to Modem 339WorkingWithCassetteTape. . . . . . . . . . . . . . . . . . . . . . .. 340Data Storage on Floppy Diskettes. . . . . . . . . . . . . . . . . . .. 342. The Game Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 343Paddles 346Light Pen 348. RS-232 Interface Description 348General Outline 348Opening an RS-232 Channel 349Getting Data From an RS-232 Channel 352Sending Data to an RS-232 Channel 353Closing an RS-232 Data Channel 354Sample BASIC Programs. . . . . . . . . . . . . . . . . . . . . . . . . . .. 356

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Receiver/Transmitter Buffer Base Location Pointers 357Zero-Page Memory Locations and Usagefor RS-232SystemInterface. . . . . . . . . . . . . . . . . . . . . .. 358Nonzero-Page Memory Locations and Usagefor RS-232System Interface.. . . . . . . . . . . . . . . . . . . . .. 358. The User Port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 359Port Pin Description 359. The Serial Bus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 362Serial Bus Pinouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 363. The Expansion Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 366. Z-80MicroprocessorCa r t r i d g e . . . . . . . . . . . . . . . . . . . . . . . . . 368Using Commodore CP/M@ . . . . . . . . . . . . . . . . . . . . . . . . . . . 369Running Commodore CP/M@ . . . . . . . . . . . . . . . . . . . . . . . . . 369

APPENDICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 373A. Abbreviations for BASICKeywords. . . . . . . . . . . . . . . . . . .. 374B. Screen Display Codes 376C. ASCIIand CHR$Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 379D. Screen and Color MemoryMaps. . . . . . . . . . . . . . . . . . . . .. 382E. Music Note Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 384F. Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 388G. VIC Chip Register Map 391H. Deriving Mathematical Functions 394I. Pinouts for Input/Output Devices. . . . . . . . . . . . . . . . . . . . .. 395J. Converting Standard BASIC Programs toCommodore 64 BASIC 398K. Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 400L. 6510 Microprocessol Chip Specifications 402M. 6526 Complex Interface Adapter (CIA)Chip Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 419N. 6566/6567 (VIC-II)Chip Specifications. . . . . . . . . . . . . . . .. 436O. 6581 Sound Interface Device (SID) Chip Specifications. .. 457P. Glossary 482

INDEX 483

COMMODORE 64 QUICK REFERENCECARD 487SCHEMATIC DIAGRAM OF THE COMMODORE 64 . . . .. 491

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INTRODUCTIONThe COMMODORE64 PROGRAMMER'SREFERENCEGUIDE has been

developed as a working tool and reference source for those of you whowant to maximize your use of the built-in capabilities of your COMMO-DORE64. Thismanual contains the information you need for your pro-grams, from the simplest example all the way to the most complex. ThePROGRAMMER'SREFERENCEGUIDE is designed so that everyone fromthe beginning BASIC programmer to the professional experienced in6502 machine language can get information to develop his or her owncreative programs. At the same time this book shows you how cleveryour COMMODORE64 really is.

This REFERENCEGUIDE is not designed to teach the BASICpro-gramming language or the 6502 machine language. There is, however,an extensive glossary of terms and a "semi-tutorial" approach to manyof the sections in the book. If you don't already have a working knowl-edge of BASICand how to use it to program, we suggest that you studythe COMMODORE64 USER'SGUIDE that came with your computer. TheUSER'SGUIDE gives you an easy to read introduction to the BASICpro-gramming language. If you still have difficulty understanding how to useBASIC then turn to the back of this book (or Appendix N in the USER'SGUIDE) and check out the Bibliography.

The COMMODORE 64 PROGRAMMER'SREFERENCEGUIDE is justthat; a reference. Like most reference books, your ability to apply theinformation creatively really depends on how much knowledge you haveabout the subject. In other words if you are a novice programmer youwill not be able to use all the facts and figures in this book until youexpand your current programming knowledge.

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HOW TO USE THIS REFERENCEGUIDEThroughout this manual certain conventional notations are used to de-

scribe the syntax (programming sentence structure) of BASIC commandsor statements and to show both the required and optional parts of eachBASIC keyword. The rules to use for interpreting statement syntax are asfollows:

1. BASIC keywords are shown in capital letters. They must appearwhere shown in the statement, entered and spelled exactly as shown.

2. Items shown within quotation marks (" ") indicate variable datawhich you must put in. Both the quotation marks and the datainside the quotes must appear where shown in each statement.

3. Items inside the square brackets ([ ]) indicate an optional state-ment parameter. A parameter is a limitation or additional qualifierfor your statements. If you use an optional parameter you mustsupply the data for that optional parameter. In addition, ellipses( . . . ) show that an optional item can be repeated as many timesas a programming line allows.4. If an item in the square brackets ([ ]) is UNDERLINED,hat meansthat you MUST use those certain characters in the optional pa-rameters, and they also have to be spelled exactly as shown.

5. Items inside angle brackets indicate variable data which youprovide. While the slash ( / ) indicates that you must make a choicebetween two mutually exclusive options.

EXAMPLE OF SYNTAX FORMAT:OPEN , [,], [": ] [,]"

EXAMPLES OF ACTUAL STATEMENTS:10 OPEN 2,8,6,"0:STOCK FOLlO,S,W"20 OPEN 1,1 ,2,"CHECKBOOK"30 OPEN 3,4When you actually apply the syntax conventions in a practical situa-

tion, the sequence of parameters in your statements might not beexactly the same as the sequence shown in syntax examples. Theexamples are not meant to show every possible sequence. They areintended to present all required and optional parameters.

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Programming examples in this book are shown with blanks separatingwords and operators for the sake of readability. Normally though,BASIC doesn't require blanks between words unless leaving them outwould give you an ambiguous or incorrect syntax.Shown below are some examples and descriptions of the symbols

used for various statement parameters in the following chapters. The listis not meant to show every possibility, but to give you a better under-standing as to how syntax examples are presented.

DESCRIPTIONA logical file numberA hardware device numberA serial bus secondarydevice addressnumberA physical disk drive numberThe name of a data or program fileLiteral data supplied bythe programmerAny BASIC data variable name orconstantUse of a string type variable requiredUse of a numeric type variablerequiredAn actual program line numberAn integer or floating-point variable

COMMODORE 64 APPLICATIONS GUIDE

When you first thought about buying a computer you probably askedyourself, "Now that I can afford to buy a computer, what can I do withit once I get one?"The great thing about your COMMODORE64 is that you can make it

do what YOU want it to do! You can make it calculate and keep track ofhome and business budget needs. You can use it for word processing.You can make it play arcade-style action games. You can make it sing.Youcan even create your own animated cartoons, and more. The bestpart of owning a COMMODORE64 is that even if it did only one of thethings listed below it would be well worth the price you paid for it. Butthe 64 is a complete computer and it does do EVERYTHINGlisted andthen some!xii INTRODUCTION

SYMBOL EXAMPLE 50 4 15

0 "TEST. DATA" "ABCDEFG" X145 AB$ 12345 1000 1.5E4


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By the way, in addition to everything here you can pick up a lot ofother creative and practical ideas by signing up with a local Commo-dore Users' Club, subscribing to the COMMODOREnd POWER/PLAYmagazines, and joining the COMMODOREINFORMATIONNETWORKonCompuServe .

APPLICATION

ACTION PACKEDGAMES

ADVERTISING &MERCHANDISING

ANIMATION

BABYSITTING

BASIC PROGRAMMING

BUSINESSSPREADSHEET

COMMUNICATION

COMMENTS/REQUIREMENTS

You can get real Bally Midway arcade gameslike Omega Race, Gorf and Wizard of Wor, aswell as "play and learn" games like MathTeacher I, Home Babysitter and CommodoreArtist.Hook your COMMODORE64 to a TV, put it ina store window with a flashing, animated,and musical message and you've got a greatpoint of purchase store display.Commodore's Sprite Graphics allow you tocreate real cartoons with 8 different levels sothat shapes can move in front of or behindeach other.The COMMODORE 64 HOME BABYSITTERcartridge can keep your youngest child occu-pied for hours and teach alphabet/ keyboardrecognition at the same time. It also teachesspecial learning concepts and relationships.Your COMMODORE64 USER'SGUIDE and theTEACH YOURSELF PROGRAMMING series ofbooks and tapes offer an excellent startingpoint.The COMMODORE 64 offers the "Easy" seriesof business aids including the most powerfulword processor and largest spreadsheetavailable for any personal computer.Enter the fascinating world of computer "net-working." If you hook a VICMODEM to yourCOMMODORE 64 you can communicate withother computer owners all around the world.

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COMPOSING SONGS

CP/M*

DEXTERITY TRAINING

EDUCATION

FOREIGN LANGUAGE

GRAPHICS AND ART

Not only that, if you join the COMMODOREINFORMATIONNETWORKon CompuServeyou can get the latest news and updates onall Commodore products, financial informa-tion, shop at home services, you can evenplay games with the friends you make throughthe information systems you join.The COMMODORE64 is equipped with themost sophisticated built-in music synthesizeravailable on any computer. It has three com-pletely programmable voices, nine full musicoctaves, and four controllable waveforms.look for Commodore Music Cartridges andCommodore Music books to help you create orreproduce all kinds of music and sound effects.Commodore offers a CP/M* add-on and ac-cess to software through an easy-to-Ioad car-tridge.Hand/Eye coordination and manual dexterityare aided by several Commodore games . . .including "Jupiter lander" and night drivingsimulation.While working with a computer is an educa-tion in itself, The COMMODORE EducationalResource Book contains general informationon the educational uses of computers. Wealso have a variety of learning cartridges de-signed to teach everything from music to mathand art to astronomy.The COMMODORE 64 programmable char-acter set lets you replace the standard char-acter set with user defined foreign languagecharacters.In addition to the Sprite Graphics mentionedabove, the COMMODORE 64 offers high-resolution, multi-color graphics plotting, pro-

xiv INTRODUCTION.CP/M is a Registered trademark of Digital Research, Inc.


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INSTRUMENTCONTROl

JOURNALS ANDCREATIVE WRITING

LlGHTPEN CONTROL

MACHINE CODEPROGRAMMING

PAYROLL & FORMSPRINTOUT

PRINTING

RECIPES

grammable characters, and combinations ofall the different graphics and character dis-play modes.Your COMMODORE 64 has a serial port,RS-232 port and a user port for use with avariety of special industrial applications. AnIEEE/488 cartridge is also available as an op-tional extra.The COMMODORE 64 will soon offer an ex-ceptional word processing system that matchesor exceeds the qualities and flexibilities ofmost "high-priced" word processors available.Of course you can save the information oneither a 1541 Disk Drive or a Datassette TMrecorder and have it printed out using a VIC-PRINTERor PLOTTER.Applications requiring the use of a lightpencan be performed by any lightpen that will fitthe COMMODORE 64 game port connector.Your COMMODORE 64 PROGRAMMER'S REF-ERENCE GUIDE includes a machine languagesection, as well as a BASIC to machine codeinterface section. There's even a bibliographyavailable for more in-depth study.The COMMODORE 64 can be programmed tohandle a variety of entry-type business appli-cations. Upper~lower case letters combinedwith C64 "business form" graphics make iteasy for you to design forms which can thenbe printed on your printer.The COMMODORE 64 interfaces with a vari-ety of dot matrix and letter quality printers aswell as plotters.You can store your favorite recipes on yourCOMMODORE 64 and its disk or cassettestorage unit, and end the need for messy rec-ipe cards that often get lost when you needthem most.

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SIMULATIONS Computer simulations let you conduct danger-ous or expensive experiments at minimum riskand cost.

SPORTS DATA The Source and CompuServe both offersports information which you can get usingyour COMMODORE64 and a VICMODEM.

STOCK QUOTES With a VICMODEM and a subscription to anyof the appropriate network services, yourCOMMODORE64 becomes your own privatestock ticker.

These are just a few of the many applications for you and yourCOMMODORE64. As you can see, for work or play, at home, in schoolor the office, your COMMODORE64 gives you a practical solution forjust about any need.

Commodore wants you to know that our support for users only STARTSwith your purchase of a Commodore computer. That's why we'vecreated two publications with Commodore information from around theworld, and a "two-way" computer information network with valuableinput for users in the U.S. and Canada from coast to coast.

In addition, we wholeheartedly encourage and support the growth ofCommodore Users' Clubs around the world. They are an excellent sourceof information for every Commodore computer owner from the beginnerto the most advanced. The magazines dnd network, which are morefully described below, have the most up-to-date information about howto get involved with the Users' Club in your area.

Finally, your local Commodore dealer is a useful source of Commo-dore support and information.POWER/PLAYThe Home Computer Magazine

When it comes to entertainment, learning at home and practical homeapplications, POWER/PLAYs THEprime source of information for Com-modore home users. Find out wh,ere your nearest user clubs are andwhat they're doing, learn about software, games, programming tech-niques, telecommunications, and new products. POWER/PLAYis yourpersonal connection to other Commodore users, outside software andhardware developers, and to Commodore itself. Published quarterly.Only $10.00 for a year of home computing excitement.xvi INTRODUCTION


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COMMODOREThe Microcomputer MagazineWidely read by educators, businessmen and students, as well as

home computerists, COMMODOREMagazine is our main vehicle forsharing exclusive information on the more technical use of Commodoresystems. Regular departments cover business, science and education,programming tips, "excerpts from a technical notebook," and manyother features of interest to anyone who uses or is thinking about pur-chasing Commodore equipment for business, scientific or educationalapplications. COMMODOREis the ideal complement to POWER/ PLAY.Published bi-monthly. Subscription price: $15.00 per year.AND FOR EVEN MORE INFORMATION . . .. . . DIAL UP OUR PAPERLESS USER MAGAZINECOMMODORE INFORMATION NETWORKThe magazine of the future is here. To supplement and enhance your

subscription to POWER/PLAYand COMMODOREmagazines, the COM-MODORE INFORMATIONNETWORK-our "paperless magazine"-isavailable now over the telephone using your Commodore computer andmodem.Join our computer club, get help with a computing problem, "talk" to

other Commodore friends, or get up-to-the-minute information on newproducts, software and educational resources. Soon you will even beable to save yourself the trouble of typing in the program listings youfind in POWER/PLAYor COMMODOREy downloading direct from theInformation Network (a new user service planned for early 1983). Thebest part is that most of the answers are there before you even ask thequestions. (How's that for service?)To call our electronic magazine you need only a modem and a sub-scription to CompuServe, one of the nation's largest telecommunica-tions networks. (To make it easy for you Commodore includes a FREEyear's subscription to CompuServe in each VICMODEM package.)Just dial your local number for the CompuServe data bank and

connect your phone to the modem. When the CompuServe video textappears on your screen type G CBM on your computer keyboard. Whenthe COMMODORE INFORMATIONNETWORK'Stable of contents, or"menu," appears on your screen choose from one of our sixteen de-partments, make yourself comfortable, and enjoy the paperless maga-zine other magazines are writing about.

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For more information, visit your Commodore dealer or contact Com-puServe customer service at 800-848-8990 (in Ohio, 614-457-8600).

COMMODORE INFORMATION NETWORKMain Menu DescriptionDirect Access CodesSpecial CommandsUser QuestionsPublic Bulletin BoardMagazines and NewslettersProducts AnnouncedCommodore News Direct

Commodore DealersEducational ResourcesUser GroupsDescriptionsQuestions and AnswersSoftware TipsTechnical TipsDirectory Descriptions

xviii INTRODUCTION

Documents

c64 Programmers Reference Guide 00 Toc Introduction