Questions tagged [commodore-64]

For questions about the different versions and products of the Commodore 64

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

A couple years ago the Toronto PET Users Group published an article (The Great Commodore/Microsoft Easter Egg War, on p. 7) about a newly discovered anti-Microsoft Easter Egg that Commodore hid in the ...
Raymond68's user avatar
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58 votes
2 answers
12k views

Why did Commodore fill their power supplies with epoxy?

If you know anything about the Commodore 64 (and other Commodores, really) you know that Commodore really went the cheap route and produced some awful power supplies. The Commodore 128 PSU isn't ...
cbmeeks's user avatar
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47 votes
5 answers
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Why are C64 games inconsistent with which joystick port they use?

The Commodore 64 has two DE-9 joystick ports. If I'm the only person that ever plays games on it, you would assume that you could just leave a joystick plugged into Port 1 and be done with it. However,...
bjb's user avatar
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47 votes
3 answers
7k views

How did C64 games handle music during gameplay?

On the C64 there was no threading, so how did games handle treating at the same time music and game code? Music requires exact timings, and the SID had to be instructed to change the note at the right ...
Stefano Borini's user avatar
46 votes
4 answers
42k views

Commodore 64 to modern TV

I've been thinking about getting a Commodore 64 machine. However, I realise there's obviously no video cables I have that will work. But when I looked online there are many people using S-Video to VGA ...
crabcrabcam's user avatar
42 votes
2 answers
5k views

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

I've always wondered why the Commodore 64 had discrete keys dedicated for the ← and ↑ symbols. If I remember correctly, they weren't used in BASIC at all, and were not very useful for drawing, either, ...
Mavrik's user avatar
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39 votes
5 answers
6k views

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

In layman's terms, please explain the reason that all the popular PSG's used in 1980s computers and game consoles provided an additional channel to generate programmable "noise". How was this "noise" ...
Brian H's user avatar
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39 votes
3 answers
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Why did the VIC-II and SID use 6 µm technology in the era of 3 µm and 1.5 µm?

In short, 3 µm looks like it was the "standard" process size at the time, and it was available to Commodore before the chips were designed. Therefore it looks like using the larger 5 to 7 µm process ...
supernoob5000's user avatar
37 votes
6 answers
6k views

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

I never had a Commodore 64 but I've always been curious what the purpose and history of some of the special keys were. In particular: C= Run/Stop Clr/Home Restore I'm mostly used to the standard ...
bjb's user avatar
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35 votes
7 answers
14k views

Why did Commodore 64 cartridge games disappear?

The Commodore 64 has a cartridge slot, but by the mid-eighties, cartridge games disappeared; everything was on tape or disk. Why? One answer that suggests itself is that by that time, a larger ...
rwallace's user avatar
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34 votes
17 answers
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Did computer games for Commodore 64 really take "25 minutes" to load "if everything went alright"?

In the Swedish-language song "Nostalgi" by Markoolio from 2003, some of the lyrics go: My first computer had 64 kB you surfed on the water, and that's that The computer games were loaded ...
Kommendåre 64's user avatar
34 votes
3 answers
2k views

Why does the C64's LIST command choke on REM statements with a Shift+L?

On the Commodore 64 and VIC-20, the LIST command will abort with a ?SYNTAX ERROR on any line that contains a REM statement with a Shift+L character. A minimal program triggering the error would look ...
Psychonaut's user avatar
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33 votes
6 answers
2k views

Dumping and archiving C64 disks

Doing spring cleaning with family, I found some old C64 disks. These are really old and no one knows what to do with them. Archiving or dumping them seems to be options but we are unsure how to do so ...
Anthony Pham's user avatar
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31 votes
2 answers
4k views

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

While perusing the schematics for the Commodore 64C (titled COMMODORE-64 B/NE) I came across a suspicious section of the power supply: The unregulated "9V" is connected to the completely ...
pipe's user avatar
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30 votes
2 answers
4k views

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

According to this article: german C64 Wiki article about the POS() command POS(π) is 20 % faster. Although in my experience it is ...
user avatar
29 votes
3 answers
4k views

What are the differences between a PAL and NTSC C64?

A lot of programs released for the Commodore 64 contained different software for the PAL or NTSC computer. Why did they have different versions of the hardware? Did the software have to be different ...
Thraka's user avatar
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28 votes
3 answers
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How did the "rub joystick port to continue" in the Creatures 2 infinite lives cheat work?

The game Creatures 2 on the Commodore 64 had an unusual cheat to get infinite lives which unlike most things on the Internet that are said to "really work" really worked! What you had to do was lick ...
komodosp's user avatar
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25 votes
1 answer
5k views

Why do all the Speech Synthesizers have that same Voice?

The first time I ever played with software speech synthesis on a microcomputer (not hardware synthesis, like in TI's Speak & Spell) was around 1983, using S.A.M for the Commodore 64. A year later,...
Brian H's user avatar
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25 votes
1 answer
4k views

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. Naively, it seems to be that it would have been more logical to put I/O and the character ROM at $B000 to $BFFF, have the ROMs in a ...
TeaRex's user avatar
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25 votes
2 answers
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Why does waggling the joystick of a C64 cause errors loading from tape?

When loading a game from the tape drive on a C64, if you wiggle the joystick around too much the program will not load correctly. Is there an explanation for this? EDIT: Perhaps someone can try to ...
WW.'s user avatar
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24 votes
1 answer
1k views

How did the C64 lockup bug and its workarounds work?

The Commodore 64 suffered from a strange bug that caused it to lock up when typing in the full-screen BASIC editor. To trigger the bug, position the cursor on the last line of the screen, type enough ...
Psychonaut's user avatar
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24 votes
1 answer
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When does the VIC-II read the sprite data?

This question is about the Commodore 64 and its graphics chip, the VIC-II. Imagine that on a particular scanline, the VIC-II needs to fetch 40 bytes (the background tiles) and since it's a badline ...
Omar and Lorraine's user avatar
23 votes
8 answers
4k views

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

When I was a kid, the "real" computers in movies looked so cool with that 80-column monochrome green text. My first computer was a VIC-20 and it always felt very "toy-like" to me ...
AvaTaylor's user avatar
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23 votes
5 answers
6k views

How can I power a C64?

I was chatting with our neighbor and after some long talking, I found out that he has a Commodore 64. I'd love to test it, however I'm not sure how to power it. How can I power a C64?
ave's user avatar
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23 votes
4 answers
5k views

How was digital sound playback achieved on the Commodore 64?

The Commodore 64 did not have any hardware dedicated to digital audio playback, so how were some games and songs able to achieve this on an unmodified and unextended Commodore 64? Did these ...
rcntxtlztn's user avatar
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23 votes
3 answers
5k views

Could you manually eject a floppy quick enough to prevent data loss?

I have the vague recollection of "Panic Ejecting" floppy disks by lifting the latch on the drive after immediately regretting a command I had typed. At the time, I was young, impulsive, and blessed ...
Brian H's user avatar
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23 votes
2 answers
2k views

What's a good way to implement this "splashing water" effect on the C64?

This pillow fighting game set in Venice depicts the two opponents fighting on a wobbly gondola on a canal. It was apparently known as "Pillow Fight" in English and as "Kissenschlacht&...
Omar and Lorraine's user avatar
22 votes
6 answers
3k views

Did home computers have mechanical interfaces to typewriters?

In the April 1985 issue of Ahoy!, a reader asks whether it is possible to hook a conventional typewriter up to his Commodore 64. Surprisingly to me, columnist David Barron answers that such ...
Psychonaut's user avatar
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22 votes
3 answers
5k views

Are pixels on the Commodore 64 square?

Are "tile pixels" the same size as "sprite pixels", and are they both square (ignoring the rule that multicolor sprites can only be colored in groups of two pixels)? By "square" I mean that the ...
Woodrow Barlow's user avatar
22 votes
5 answers
6k views

How to detect a real Commodore 64, THEC64, or VICE emulator in software?

Some programs notice if they are run on a real Commodore 64 or an emulator. For example, this demo from 2007 stops on VICE emulator 3.2 with the message "No VIC inside". How is this done? I ...
Peter B.'s user avatar
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22 votes
1 answer
3k views

How does the C64 get an accurate TOD clock on both 60 Hz and 50 Hz power?

The C64 has two Time of Day (TOD) clocks, one in each of its 6526 CIA chips U1 and U2. These calculate time based on a 60 Hz or 50 Hz input to the TOD pin (pin 19); the clock input frequency assumed ...
cjs's user avatar
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21 votes
5 answers
7k views

Were the custom chips in the Amiga exploited for their hardware bugs like the ones in the C64 and Atari 8 bit computers were?

Here we are some decades on from the C64, and other 8 bit computers. New ideas that resulted in some new graphics effect or mode seem to happen, though we may be near the end of all that. Took a ...
Spud's user avatar
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21 votes
5 answers
5k views

What kind of television set would work with the Commodore 64?

I found out all my SmartTVs don't work because they are too modern for my old computer. I am a young owner of a Commodore 64, so please bear with me as this machine is a decade older than me. I do ...
Travis Wells's user avatar
21 votes
3 answers
4k views

How can I overclock my Commodore 64?

My Commodore 64 is running quite slow, and my friends want it to be faster, thus overclocking it. But no one knows exactly how to do that. With our current "modern" stuff, nothing seems to help my ...
Anthony Pham's user avatar
  • 2,464
21 votes
4 answers
2k views

Obscure uses of the Commodore 8050/1541 disk drive

When I was working for a foundry consultancy, we did the following Download routines to add delays when writing certain tracks. This was a security feature. When the program started, it would try ...
cup's user avatar
  • 2,515
21 votes
5 answers
2k views

What is the history of DE-9 joystick ports?

The Commodore 64 and the Atari 2600 had compatible joystick ports. Commodore, Atari, and third-party companies like Wico made joysticks supporting that standard. Did this standard have a name? ...
Ben Jackson's user avatar
21 votes
3 answers
7k views

6510 clock rate of C64: Why was it considerably slower than the 6502 of the Atari 800?

According to Wikipedia, the Atari 8 bit series had a 6502 running at ~1.8 MHz. Why was the clock speed of the 6510 for the C64, which was designed a couple of years later, considerable slower? Was the ...
Marco's user avatar
  • 1,387
21 votes
5 answers
2k views

Why the disparity between the screencodes and the character codes?

The Commodore 64, and possibly others, I don't know, have character codes (These map integers to characters, in the same way that ASCII does) and there are screen codes (The offset which the VIC-II ...
Omar and Lorraine's user avatar
20 votes
6 answers
3k views

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

When you are getting INPUT in Commodore BASIC it always adds a question mark at the end of the string you want to show. Is there a way to suppress the question mark when using the INPUT command?
user avatar
20 votes
6 answers
3k views

Does lossy audio compression damage datasette data?

I grew up with the C64 and had software on cassette tapes. These days, you can find "backups" of this software all over the internet, even in mp3 format (by recording the audio signal with a ...
Jeroen Jacobs's user avatar
20 votes
1 answer
2k views

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

Most early microcomputers provided either a dedicated key (e.g. Apple ][), keyboard combination (e.g. PC clones), or dedicated hardware button (countless examples) to "Reset" the computer. ...
Brian H's user avatar
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20 votes
2 answers
842 views

What was the end of line convention for text files on the 8-bit Commodores

A two part question: Did an agreed upon convention for end of line (EOL) within text files exist on the 8-bit Commodores? If there was a convention, what was it?
Shannon Severance's user avatar
20 votes
2 answers
3k views

How to check the C64 graphics mode used by Maniac Mansion

I have been investigating the MS-DOS port of the C64's Maniac Mansion game. The original MS-DOS port used the C64-specific character map to draw the various backgrounds in the game. I noticed that ...
user avatar
19 votes
12 answers
6k views

Did early assembly games use hardcoded memory locations?

In the era of C64, Apple][ GS, and SNES, did the games use hardcoded memory locations, or did they let the assembler help them (like modern assemblers)? If yes, how did they manage the memory?
Ignis Incendio's user avatar
19 votes
3 answers
1k views

Commercial C64 software implemented in Forth?

There has been several implementations of Forth that were running on, and targeting, the C64. Were there any commercial software releases (not throw-away hobby projects or in-house utilities) that ...
Cactus's user avatar
  • 2,670
19 votes
4 answers
3k views

What graphical effects can be created by changing the VIC-II settings?

I read in this answer that one could create graphics effects outside the usual specifications of the hardware by changing the settings of the machine's VIC-II at specific cycles during the video ...
wizzwizz4's user avatar
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19 votes
3 answers
2k views

Why was the VIC-II restricted to a hard-coded palette?

The MOS VIC in the VIC-20 and the MOS VIC-II in the C64 were capable of outputting 16 colours drawn from a hard-coded palette. It's clear that the palette size was fixed at 16 colours as a memory-...
Psychonaut's user avatar
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19 votes
3 answers
2k views

Can a Commodore 64 use two screen modes on one scanline?

Many games, for example, Maniac Mansion, or Kissenschlacht, use two screen modes. Oftentimes, a bitmap mode for the main screen, and a text mode for the lower part which displays scores or whatever. ...
Omar and Lorraine's user avatar
19 votes
1 answer
1k views

Any difference between a VIC-1541 and a C64-1541?

I have both a beige VIC-20 styled VIC-1541 disk drive and the later brown C64 1541 drive. Is there a difference between them (besides how they look)?
Thraka's user avatar
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19 votes
0 answers
1k views

Oxford C compiler for Commodore 64

I kept one floppy from my Commodore 128 (which I used mostly in C64 mode), labelled ‘Oxford C compiler’. It is a 5.25″ floppy. Don't ask me why I kept just this one; probably because I thought I ...
Michel Keijzers's user avatar

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