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239 votes
Accepted

How did Commodore's anti-Microsoft Easter Egg work?

I'm the author of the TPUG article. The "BILL GATES SUCKS" message isn't really an Easter egg; that was just a conceit of mine to make the article a bit more interesting and to turn it into a bit of ...
Psychonaut's user avatar
  • 7,541
74 votes

Did computer games for Commodore 64 really take "25 minutes" to load "if everything went alright"?

Theoretically it could take 25 minutes (or more), in practice it never did. Theoretically it could, because the C-64's built-in tape handling routines had a data rate of about 300 bit/s. That's 37.5 ...
Michael Graf's user avatar
  • 10.1k
64 votes

How did Commodore's anti-Microsoft Easter Egg work?

That's not a real easter egg. Someone just made an effort to find random seeds that produce the numbers to create the intended words. It would be an easter egg if the seed numbers were in some way ...
Zac67's user avatar
  • 3,904
64 votes
Accepted

Why did Commodore fill their power supplies with epoxy?

Epoxy offers two advantages -- it is an electrical insulator, and it conducts heat better than air. Transformers and inductors are generally potted with epoxy for this reason. [ref] Perhaps the cause ...
RichF's user avatar
  • 9,326
63 votes
Accepted

Why are C64 games inconsistent with which joystick port they use?

As Wilson points out in his answer, it has to do with how the CIA chips interact with the keyboard and the joystick ports, and the confusion that can arise trying to determine where input is being ...
Geo...'s user avatar
  • 10.2k
62 votes

Why did the VIC-20 and C64 have only 22 and 40 columns when the earlier PET had 80 column text?

One reason was likely that the VIC-20 and C64 did not have their own displays, but were designed to be connected to a television set. The interface between the computer and the television was not ...
Greg Hewgill's user avatar
  • 7,009
60 votes
Accepted

Why do programmable sound generators like SID include a noise generator?

One basic distinction in acoustics is the one between sounds that oscillate with a pattern that is repeated over time and sounds that are chaotic in nature, and show no repetitive pattern. Sounds ...
Schmuddi's user avatar
  • 925
53 votes

How did C64 games handle music during gameplay?

Your assumptions about timing and interrupts are correct. Actually, it is surprisingly easy to add SID music to games because they tend to follow a basic pattern. Compose the tune in a C64 SID editor....
Brian H's user avatar
  • 60.8k
51 votes
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Why did Commodore 64 cartridge games disappear?

Time to market was another factor. I worked in the games industry in the 1980s and when we were getting the final game from the developer, mastering to cassette and disk took just hours before they ...
David Partington's user avatar
49 votes
Accepted

Why did the C64 have ← and ↑ as dedicated keys?

The ← and ↑ symbols were originally included in ASCII-1963 as programming operators. They were used in a number of programming languages at the time, but the only common usage left today is in ...
mnem's user avatar
  • 4,545
48 votes

Why did the VIC-II and SID use 6 µm technology in the era of 3 µm and 1.5 µm?

After some more research, I believe I've stumbled across the real answer: The VIC-II and SID used a larger process node size because Commodore's fabrication line circa 1981 was uniquely positioned ...
supernoob5000's user avatar
42 votes
Accepted

How can I store a machine language program to disk on a C64?

I have looked all around online, but I cannot find on how to do this. Well, you won't, as the C64's BASIC2 does not provide such function or a monitor. The old PETs had TIM in ROM, while BASIC 3.5 ...
Raffzahn's user avatar
  • 224k
41 votes
Accepted

Why do all the Speech Synthesizers have that same Voice?

The ones you list are all S.A.M, from what is now SoftVoice Inc. It was developed first for the Apple II, Lisa, Atari 8-bit machines and the Commodore 64; based on awareness of those versions, the ...
Tommy's user avatar
  • 37.3k
39 votes
Accepted

C64 BASIC: How to suppress the '?' sign when using the INPUT command?

Use the INPUT# command. The INPUT# command is meant for non-interactive I/O on files or devices, i.e. reading from a file on disk, serial port, whatever. Because it is non-interactive, it will not ...
followed Monica to Codidact's user avatar
38 votes
Accepted

Commodore 64 to modern TV

The VIC-II chip inside the C64 computer outputs a S-Video signal, which is mixed and modulated into the matal box that contains the UHF modulator circuit. Earlier models made composite video available ...
mcleod_ideafix's user avatar
37 votes

Why did Commodore 64 cartridge games disappear?

A cartridge was limited to 16 kbytes ROM, and some were only 8k. There would be plenty of RAM to use, but the code and data must fit into the 16 kbytes. As programs became more sophisticated, the ...
RichF's user avatar
  • 9,326
36 votes
Accepted

How can I overclock my Commodore 64?

The basic principle behind overclocking is that if you speed up a clock, everything that runs from that clock will go faster. But there are some parts of your computer that you don't want to speed up,...
Ken Gober's user avatar
  • 11.4k
35 votes

What was the purpose and history of the C64's special keys?

The Restore key triggered the NMI (non-maskable interrupt) line; to actually have an effect it had to be combined with Run/Stop - it would soft-reset the machine (via an indirect jump vector that ...
Joe's user avatar
  • 1,582
35 votes
Accepted

C64: Why is POS(π) faster than POS(0)?

That interpreter apparently parses the source text, or at least the numerical literal values, at every execution. π is a single-byte magic token, therefore, as soon as it is recognized, it is ...
Leo B.'s user avatar
  • 19.3k
35 votes
Accepted

What is the Commodore 64C "France version" and why does it need a beefy resistor?

As noted in the question, the resistor is there to allow something to consume more current without voltage dropping too much. But what consumes more current may not visible in the schematics. France (...
Justme's user avatar
  • 33k
34 votes

What's the deal with Commodore's RESTORE key?

TL;DR: There is no fundamental difference just because a different interrupt is used. For all practical purpose the Restore-key works like the Apple II's Reset-key or the PC's Ctrl-Alt-Del key ...
Raffzahn's user avatar
  • 224k
33 votes
Accepted

Why does the Commodore 64 have 4K of non-banked RAM at $C000?

I wonder why the Commodore 64 memory map was created as it was. As so often it helps to look at a machine's predecessor; in the case of the C64 that's not the VIC 20, but the Max Machine, a very ...
Raffzahn's user avatar
  • 224k
31 votes
Accepted

Install Commodore 64 on VirtualBox

It's not possible. VirtualBox only supports emulating IBM-compatible x86 and x86-64 systems. The Commodore 64 uses a 6510 CPU and a wildly different architecture. In order to run Commodore 64 ...
Mark's user avatar
  • 8,585
31 votes

Why did the VIC-20 and C64 have only 22 and 40 columns when the earlier PET had 80 column text?

Use of TV as monitor is the reason for these low resolutions. The issue is that the color resolution of TV is very low. While B&W TV could resolve pixel small enough for ~400 to ~600 pixels, color ...
Patrick Schlüter's user avatar
29 votes
Accepted

What are the differences between a PAL and NTSC C64?

Hardware-wise, the Commodore 64, like most early computers, was synchronized to its graphics output: in the case of the C64, the CPU clock was derived from the timing crystal in the video hardware. ...
Mark's user avatar
  • 8,585
28 votes
Accepted

Dumping and archiving C64 disks

The simplest method of archiving old C-64 disks would be to get a ZoomFloppy and a 1571 floppy drive from eBay. I say 1571 because it's much less likely to have alignment problems. The ZoomFloppy ...
geneb's user avatar
  • 396
28 votes
Accepted

How to use BASIC after "LOAD "$",8 on the C64

Try using the "new" command. This clears BASIC's memory, so that you can write a new program.
Ken Gober's user avatar
  • 11.4k

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