• Tag Archives 6502
  • Compute! (March 1981)

    Source: Compute! – Issue Number 10 – March 1981

    Compute! was a popular multi-format magazine that covered various computers throughout its long life which started in 1979 and lasted until the 1990s. Throughout its early life, it strictly covered computers based on the 6502 processor. The March 1981 issue includes:

    Table of Contents

    • The Editor’s Notes – The editor opines on software piracy vs. the right to back-up software that you buy.
    • A 6502 Version of the Winter Consumer Electronics Show: January ’81 – News related to 6502 based computers at the Winter CES. The biggest product introduced that year was the Commodore VIC-20.
    • The Beginner’s Page – Some beginner information about BASIC, operating systems, ROM, RAM and storage media.
    • Computers and Society – A look at communications between user and computer via programming languages. LOGO and PILOT are emphasized while BASIC and PASCAL are also mentioned.
    • Taking the Plunge – Machine Language Programming for Beginners – An introductory guide to machine language on the PET though it is applicable to other machines of the time as well. The differences between BASIC, machine language and assembly code are discussed.
    • Computer Communications Experiments – An article on building an RS-232C interface which can be used for modems and other things.
    • Basics of Light Pen Operation – In the early days of computing, light pens were a fairly common user interface option. This article describes in technical detail how they work.
    • Getting the Most from your Pet Cassette Deck – The kinds of cassettes you should use, how to shorten they time it takes to search for programs, and more.
    • The Mysterious and Unpredictable RND – Part 3 – Part 3 of a multi-part series on random number generation in BASIC on the PET. This part demonstrates a dice rolling program using multiple dice.
    • A CAI Program Called Linear Equation – A type-in program for Computer Aided Instruction of Linear Equations.
    • Hex Conversion Using the 6502’s Decimal Mode – A machine language method for converting to and from hexadecimal numbers.

    The Apple Gazette

    • Clearing the Apple II Low-Resolution Graphics Screen – Several BASIC methods for clearing the screen.
    • Fun with Apple and PASCAL – A type-in PASCAL arcade style shooter game for the Apple II (basically shoot at the falling shapes).
    • Flipping your Disk – A guide to making your single side disks double-sided. Essentially, this could be accomplished just by clipping a notch in the side of the disk that didn’t already have one. This worked for a variety of 8-bit computers. Drives were generally single sided so you still had to flip the disk over to read and write data to the second side.

    The Atari Gazette

    • Designing Your Own Atari Character Sets – Creating custom character sets on the Atari 8-bit.
    • Atari Basic: A Line Renumbering Utility – A type-in utility for renumbering the lines of a BASIC program. This was important sometimes because you could run out of line numbers. Every line of code in basic started with a line number. If you needed to add code in between two lines then there would have to be available numbers to do so. If you were unwise enough to make every line number consecutive, that could be problematic. It was common practice to number lines by 10s (first line is 10 second is 20, etc.). However, you never know when you might need more extra line numbers in between.
    • Atari Memory Dump and Dissassembler – A type-in program that will both dump the contents of memory locations to disk or disassemble lines of code.
    • Formatted Output for Atari BASIC – An article with two subroutines for helping you to produce nicely formatted output from BASIC.
    • Random Color Switching while Idle – A method to prevent Atari’s built-in color switching screen saver from kicking in. Pressing a key resets the time for this but when playing a games, you may not be pressing any keys.

    The OSI Gazette

    • A Small Operating System: OS65D the Kernel – The final part in a series on the OS65D operating system.
    • A Six-Gun Shootout Game for the OSI C1P – A type-in BASIC game that sounds a bit like Outlaw on the Atari 2600.

    The PET Gazette

    • Learning About Garbage Collection – Garbage collection (memory reclamation) was necessary on PET machines with certain ROM revision in order to reclaim memory used by strings. Here are a couple of short routines to do that.
    • PET Machine Language Graphics – A machine language graphics subroutine for the PET that provides a variety of graphics functions.
    • Disk File Recovery Program – A type-in program for the PET that can recover accidentally deleted files.
    • PET Exec Hello – A type-in program for automatically executing commands when booting from disk.
    • A Flexible Input Subroutine – A type-in subroutine in BASIC that can handle various types of input.
    • Universal Tape Append for PET/CBM – A type in program that allows for one program to be appended to another on cassette.

    The SBC Gazette

    • Experimenting with the 6551 ACIA – Information for interfacing, operating and controlling a 6441 ACIA with a 6502. The 6551 is used primarily for communications.
    • A Vocal Hex Dump for the KIM-1 – A program designed to work with a speech synthesizer to speak the data in a given memory location.
    • Expanding KIM Style 6502 Single Board Computers – Part 3 of 3 – The final part in a series on expanding the KIM (and KIM-style) single board computers. Basically a series on how to use the bus expansion connector of these machines.
    • Cassette I/O with AIM-65 BASIC – How to make your BASIC program read and write to/from cassette on the AIM 65.

    New Products

    • New Products – Commodore releases disaster relief software used during the fire at the MGM Grand Hotel on November 22, 1980, Personal Software Inc. releases MicroChess and Checker King for the Atari 400/800, Cimarron Corp. announces Legal Time Accounting (accounts receivable and matter tracking for the legal profession) for the Commodore 8032, Microcomputer Software Inc. releases The Landlord apartment management software for the Apple II, Microware releases Scientific Plotter graph producing software for the Apple II, Axlon announces 32K RAM expansion for the Atari 400/800, and much more.

    …and more!


  • Compute! (October 1981)

    Source: Compute! – Issue Number 17 – October 1981

    Compute! is a home computer magazine that got its start all the way back in 1979. Later on, it tended to be less technical than something like Byte but by today’s standards, all computer magazines were somewhat technical when this issue was published in October 1981. At the time, Compute! covered computers based on the 6502 processors such as the Commodore PET, Apple II, Atari 400/800, VIC-20 and others. This issue includes:

    Columns

    • The Editor’s Notes – Atari reduces prices in the wake of the introduction of the VIC-20 (they would ultimately lose the price war later on vs. the Commodore 64), IBM enters the personal computer market, Atari wins school contract in Minnesota, and more.
    • Computers and Society – Appropriate applications for home computers.
    • Readers Feedback – A commentary on the maturing of the computer industry and Computer Aided Instruction.
    • Ask the Readers – A question answered about the Apple II and TV interference and questions asked about video terminal options for an OSI computer, the 3040 Floppy Disk Unit for the PET, and more.
    • Basically Useful BASIC: Automatic DATA Statements For CBM and Atari – A type-in program that converts machine language code into BASIC DATA statements.
    • The Beginner’s Page – Organizing and processing data with computers.
    • VIC-20 News – The latest released for the new VIC-20 including the VIC Graphics Printer from Axiom, a new disk drive (this would become the 1540), various memory expansion cartridges, an RS-232 adapter for connecting a modem, plus lots of software including Blackjack, Slither/Superslither, Biorhythm Compatibility, Space Math, Car Chase, Blue Meanies from outer Space, Programmer’s Aid (adds new BASIC commands), and more.
    • Guest Commentary: A Software Publisher’s View on Software Pricing and Service Policies – A commentary on software licensing from a publisher’s perspective.
    • What is a Modem, and Why Do I Need One? Part II – Part II of this multipart series includes information on how to use a modem, what type of modem to get, and technical modem details.
    • More Machine Language for Beginners – A program that provides a way to secure private files is used as a way to teach machine language techniques.
    • Undeleteable Lines – A technique for inserting lines of code in a BASIC program that cannot easily be deleted. Works on the Apple II and Commodore PETs.
    • Inverting a Matrix – A program for the TRS-80 for inverting a matrix.
    • New Products – A brief look at new products including the new 300bps AUTO-CAT modem from Novation, a TV/Monitor stand for the Apple II and Atari, VisiFile filing/database program for the Apple II, a software development system for the Commodore PET, Apple II, and Atari 400/800 from Eastern House Software, and more.

    The Apple Gazette

    • Budgeting On the Apple – A type in program for the Apple II that helps with budgeting tasks.
    • Named GOSUBs – A machine language routine that allows you to use named GOSUBs (instead of just line numbers) in BASIC programs.
    • A Tape “EXEC” For Applesoft: Loading Machine Language Programs Part II – A program that allows you to load both a BASIC program and ML routines it uses from tape.
    • Switching Cleanly From Text To Graphics – Normally when switching from text to graphics mode on the Apple II, garbage will briefly appear on the screen. This bit of code that you can implement in your own programs prevents that from happening creating cleaner transitions.
    • Interfacing the CCS 7710A Asynchronous Serial Card – Instructions for building a printer interface for the Apple II using the specified serial card.

    The Atari Gazette

    • Cassette Boot-Tape Generation From DOS 2.0S Binary Load File – A technique for creating a bootable tape on the Atari 400/800.
    • Beware The RAMTOP Dragon – A technique for creating protected memory areas…especially from Atari’s memory management.
    • Documented Atari Bugs – A detailed description of bugs in Atari OS and BASIC software.
    • Graph It On The Atari – A type in program for creating plots and graphs.
    • Extending Player Missile Graphics – A machine language program for enhancing the capabilities of Atari’s Player Missile Graphics (sprites).
    • Atari 400/800 Variable Name Utility – A type in program that will display the contents of the variable name table which lets you know which variable names are already in use.
    • Insight: Atari – How to use calculated GOTO and GOSUB statements.
    • Overview: “Letter Perfect” Word Processing on the Atari – A review of Letter Perfect, a $149 word processor for Atari computers.
    • Atari Disk File Dump – A type-in program that will provide a hex dump of any program on disk. This works with Atari 810 and 815 disk drives.
    • Atari Program Library – A type-in program that helps you catalog your software by comparing disk contents with what is already in the database and adding whatever is missing.

    The Pet Gazette

    • Practical Pet Printing Primer for Perplexed Programmers – A type-in program that helps you to print out program listings in a reasonable format.
    • Odds And Ends: A Fat Forty Bug – Illustration of a bug that sometimes occurs when running BASIC 4.0 programs on a PET with 12-inch screens that was originally written for 4-inch screens.
    • Machine Language: What’s Your Sign? – Using signed vs. unsigned numbers.
    • Train Your Pet To Run VIC Programs – A technique for getting VIC BASIC programs to run on the PET.
    • Converting To Fat-40 – A tutorial for converting programs written for 9/10-inch PET 4032 to the 12-inch 40-column PET 4032.
    • High Resolution Bar Graphs For The Pet – A type-in program for creating bar graphs on the PET
    • Waking Up The PET Screen – A software routine that can create reverse field blinking anywhere on the screen at variable rates.
    • Interfacing A BSR X-10 AC Remote Control System – Long before Alexa, X-10 systems were a way to create home automation. This article describes interfacing such a system with a Commodore PET.
    • Using Non-Pin-Feed Forms In The 2022 – A way to print on standard checks and bank deposit forms using the 2022 printer.
    • How And Why You Should Use PEEK (155) Instead Of Get – A better way to detect key presses when multiple keys are pressed at the same time (e.g. as might happen in two player games).

    The SBC Gazette

    • AIM 65 BASIC Floating Point Arithmetic From Machine Language – How to use floating point numbers on the SBC.
    • A General Purpose BCD-To-Binary Routine – A type-in program that will convert a BCD number with any number of digits to a binary number.

    …and more!


  • Compute! (August 1981)

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    Source: Compute! – Issue Number 15 – August 1981

    If you happened to be a computer owner in 1981 then Compute! would have definitely been a magazine that you would have wanted to subscribe to. The magazine lasted for more than a decade and in these early days it was exclusively covering 8-bit computers based on the 6502 processor. There were more of these than you might think.

    The August 1981 issue includes:

    • The Editor’s Notes
    • Ask The Readers
    • Computers And Society: Some Speculations On The Well-Played Game, Part II
    • The Beginner’s Page
    • Basically Useful Basic: Checking Randomness Of Random Number Generators
    • Trenton: The Original Computer Festival
    • Basic Oneliners: Minimize Code And Maximize Speed
    • Computer Assisted Instruction – Worth The Effort?
    • Wolves, Caribou, And Other Problems
    • Add A Programmable Sound Generator
    • The Carry Bit – What It Is And How It Works
    • The Floating-Point Division Routine
    • Practical Aspects Of Assembly Language: Part II
    • The Apple Gazette
      • Apple Disk Motor Control
      • Interfacing The Apple To 6500 Family Peripherals
      • A Cassette Tape Monitor For The Apple
      • Diskette Sector Space In A Greeting Program
    • The Atari Gazette
      • Restoring And Updating Data On The Atari
      • Easy Reading Of The Atari Joystick
      • Poem Writer
      • Supercube Update
      • Atari Sound Utility
      • Blockade For The Atari
      • Define A Line On The Atari
    • The OSI Gazette
      • The OSI RS232 Port And The High Speed Printer Interface
    • The Pet Gazette
      • The CBM “Fat 40” – Boon Or Bane?
      • Digital Arrayment
      • Keyword
      • CBM/PET Loading, Chaining And Overlaying
      • Converting Pet Basic Programs To ASCII Files
    • The Single Board Computer Gazette
      • The Single Board 6502
      • Nuts And Volts: Build Your Own Controllers Part II
    • New Products
    • Advertiser’s Index

    …and more!