Latest news
-
The July Issue has Shipped!
The July 2026 Physical Edition of COMPUTE!’s Gazette has officially SHIPPED! This one’s special — it’s our One-Year Anniversary Issue (Vol. 2, Issue 7),…
From Our Readers
By Editors & Readers — originally published in COMPUTE!'s Gazette Issue 2, August 1983
Off-Center Screen
Here's my question: Where are the memory locations on the Commodore 64 to center the screen? For the VIC, the locations are on the VIC chip at 36864 and 36865. Have I overlooked something somewhere? I would appreciate it if you could answer my question for myself and other readers who might be wondering the same thing.John Van Winkle
As you mentioned, the VIC chip (which controls the video output in the VIC-20) has the ability to adjust the horizontal and vertical positioning of the screen. Unfortunately, this ability to center the screen display on your monitor or TV is not available on the VIC II chip, which controls the video output on the Commodore 64. There are locations that can be POKEd to adjust the positioning of the output on the screen (53265, 53270), but these locations are not the answer to your problem. While the print characters are moved, the screen is left behind.
Mystery Keys
After looking through the Commodore 64 Programmer's Reference Guide several times, I still have no idea how to assign functions to the four keys to the right of the keyboard (F-keys). Could you give an example of this? Also, is it simply a matter of POKEing a location? How does one find out what those precise locations are? Any help will be appreciated.J. W. Hewitt
The easiest way to assign functions in a program to the special function keys is via the GET statement in BASIC. This can be accomplished with an IF-THEN statement in the same way you would for any other key on the keyboard. Enter the following short program on your VIC or 64 for an example:
Watch future issues of COMPUTE!'s Gazette for full-length articles which will describe in detail how to program the special function keys on both the VIC-20 and Commodore 64.
Which Monitor?
I would like information on monitors for my computer. I own a VIC-20, but haven't seen information on what monitors are on the market and best-suited to buy. Maybe an article put together by this magazine to show what is out there would help me and others decide what to buy. Any information would help.Maurice H. Albaugh
There are many monitors and TV sets on the market (both black and white and color) that are suitable for use with your computer. Commodore recently introduced a color monitor that is especially designed for use with the 64. The suggested retail price for this monitor is $299.95. If you can wait a few months, COMPUTE!'s Gazette is planning an article similar to the one you suggested.
Disk Drive Conversion
I own a VIC-20 with a 1540 disk drive. I and a few of my friends are thinking about buying the Commodore 64. While considering the differences between the 1540 and 1541 disk drives, it has been rumored that the 1540 can be changed to a 1541 by replacing a ROM chip. My problem is in trying to find someone or a store that can replace this chip for me. Do I have to bring it to a Commodore dealer or is it a simple replacement that can be done at home?David Leung
It's true that a 1540 can be converted into a 1541 by changing one Read Only Memory (ROM) chip. Check with your local Commodore dealer to see when this chip will become available. After conversion, the drive will still work with VIC. As general rule, any hardware modification? to
be performed upon any computer or peripheral (such as disk drive) should be performed by an authorized technician. Performing "home modifications" may damage your unit and void your warranty at the same time. To see how you can use your 1540 disk drive successfully with your Commodore 64, refer to "Power BASIC: Using 1540 Disk Drive And Commodore 64" elsewhere in this issue.
Dual Drive Lock-Up
I have recently purchased one of the new Commodore 64 computers and so far am very pleased with its performance. also purchased second
disk drive (both are VIC-154 Is), and if go by the directions in the disk drive manual, and turn my computer on last, the serial bus gets hung up.
I have conferred with other Commodore owners, and they also have experienced this same problem. My question is: Does it really hurt to turn on the disk drives after the computer, and do you know if Commodore expects to remedy this situation?William Davies
Although it is always good idea to follow the manufacturer's instructions and turn on your computer last, this is probably not the cause of your problem. All disk drives default to the same device number (#8 for the 1541) upon power-up. What is happening is that at power-up the computer is sensing two disk drives on the serial bus with the same device number (8), thus confusing the computer. The answer to your question can be found near the back of your VIC-1541 User's Manual. To operate two or more disk drives on the 64 at the same time (the 64 can handle up to five), each drive must be assigned different device number. This can be accomplished via software (programming) each
time you power up, or by hardware modifications, which will make the device number assignments permanent. Instructions for both methods can be found in your 1541 manual.
Standard Recorders OK?
Can standard tape cassette machine be used with the VIC-20 and the Commodore 64, or must purchase the C2N cassette from Commodore?Eimer Aydelotle
There are few adapters and interfaces made by independent companies which enable you to use standard cassette decks with your VIC or Commodore 64. Watch the News Products section of this magazine for announcements. COMPUTE!'s Gazette may review some of these products also. For more information on this subject, see "Does Your Computer Need Cassette Recorder?" in the July 1983 issue.
Jumping Screens
When connecting my VIC-20 to my Zenith System III TV, know how to POKE 36864,133 to keep the screen from jumping. However, when using
cartridge, have no control over the VIC-20. The instructions with the cartridge caution the user about putting in or taking nut the cartridge
while the computer is on. How do prevent the screen from jumping when using cartridge?Mitchell Bers
If the cartridge instructions do not mention an option for stopping the screen from jumping, then you can't. Usually, when you plug in game or any other cartridge, control of the keyboard (and the computer) is handled by the cartridge. "Freezing up" the keyboard is one of the means that programmers use to protect their programs from being copied. A well-written program will include options for adjusting the screen. For instance, the instructions may read, "Press F-l to change screen/border colors." Many VIC-20 games let you center the screen on your TV. In this case, you just "push" the screen (usually with cursor keys or joystick) completely off the left side of the screen until it wraps around and reappears from the right.
Cartridge Compatibility
Will the VIC-20 Programmer's Aid cartridge work on the Commodore 64?John Auresto
No, it will not. The cartridge ports on the VIC-20 and the Commodore 64 are different sizes. Your Programmer's Aid cartridge will not physically fit into the Commodore 64, and a C64 cartridge will not fit into the VIC-20. Even if you could, the cartridge is still written specifically for the VIC-20. It's like running BASIC program written for the VIC-20 on your 64. The screen width is different, and all the "memory locations" have moved. There has been talk of third-party adapters becoming available in the future, but us of this writing, we know of nothing available to consumers.
By Tom R. Halfhill — originally published in COMPUTE!'s Gazette Issue 2, August 1983
Each month, COMPUTE!'s Gazette for Commodore will tackle some common questions we are asked by new VIC-20/Commodore 64 owners and by people shopping for their first home computer.
Q. I recently bought a Commodore disk drive. When I try to save programs on some new blank disks I bought, something goes wrong. The red light on the disk drive starts flashing, and the program is not saved. I've tried this with several disks, all brand-new, and none of them work. What is happening?
A. As you probably know, a flashing red light on a Commodore disk drive indicates some sort of error condition. There are several things to check for if you have this problem. Some might seem obvious, but check them anyway.
First, if you have a Commodore 64, make sure you are using a VIC-1541 disk drive. The older VIC-1540 drives – which look identical – will not work with the 64 without special adjustments. The 1540 drives are intended for VIC-20s. The newer 1541 drives work with both computers.
Second, check all the plug connections. Be certain the plugs are firmly seated.
Third, make sure the disk drive is level. We've found that some Commodore disk drives are sensitive to this.
Fourth, the disk drive should not be too near the TV set or monitor. This goes for Datassette recorders, cassette tapes, and disks, too. TVs and monitors generate strong magnetic fields which can interfere with disk drives and recorders, and which can erase tapes and disks. Try moving the disk drive or Datassette as far away from the TV as its cord allows. Sometimes it helps to move the storage device to the other side of the TV, because some TVs generate a stronger magnetic field on one side than on the other.
Fifth, examine the floppy disk on which you're trying to save the program. When you're holding the disk as if inserting it in the drive, you should see a tiny notch cut into the left side of the protective sleeve. This is a write-enable notch. The notch allows data to be recorded on the disk. If the notch is absent, or covered with a piece of tape, the disk is write-protected. This means the disk drive will read the disk and load programs, but will not allow programs to be saved. Commercial software on disk usually is write-protected so you can't accidentally erase it. New blank disks should have uncovered notches. Never defeat the write-protection on a disk unless you're sure you know what you're doing.
The final problem to check for actually happened to someone we know. The disk drive worked fine with the disk that came with it, but would not save programs on some new blank disks – the drive would stop with the red light flashing. After checking everything else, it turned out the new disks were not formatted. Without going into detail here, formatting is basically a way of preparing a new disk so the disk drive can use it. All new disks must be formatted before their first use. Once a disk is formatted, it need never be formatted again – unless you want to reuse it for some other purpose (formatting completely erases a disk). New blank disks are not sold preformatted because different brands of computers use different disk formats, and the formats usually are incompatible.
To learn how to format a new disk, consult page 15 of the VIC-1541 User's Manual, or pages 17 and 18 of the VIC-1540 User's Manual.
Q. Why do I have to press the RETURN key each time I type in a command or a line of a BASIC program?
A. To tell the computer to accept and act on what you've typed.
When you type something on the keyboard, even though it appears on the screen, the computer is not aware of anything until you press RETURN. Before pressing RETURN; you are free to back up the cursor and make changes to your typing. Pressing RETURN tells the computer to accept the input, and it will respond in one of two ways:
If you do not type a number before the input, the computer will act on the input immediately after you press RETURN. This is called immediate mode or command mode. For example, if you type PRINT "HELLO" and press RETURN, the computer will immediately print the word HELLO on the screen, or anything else you've typed between the quotation marks. The computer interprets PRINT as an immediate mode command.
But if you type 10 PRINT "HELLO" and press RETURN, nothing happens immediately. The number 10 (or any number up to 63999) tells the computer that what follows is a line of a program.
The computer then interprets PRINT as a program instruction. It will not execute, or carry out, the instruction until you run the program by typing the command RUN (followed, of course, by a RETURN).
I'm hoping this magazine will be going for a long time.
Typing in BASIC programs as an '80s kid launched my 25-year software engineering career. Seeing this revival effort means a great deal.
I keep an older tablet loaded with classic C64 magazines from back in the day, and I've started adding your new issues to the collection. It's a challenge to unplug from digital distractions — and your magazine is part of how I do it.
The quality and value are outstanding — I collect every new issue right alongside my nearly complete original print run from the 1980s.
Congratulations on the relaunch — every issue since July [2025] has continued to amaze me. It's been years since I've had a magazine subscription, and I forgot how much I missed pulling it out of the mailbox and enjoying that new magazine smell all over again.