238 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 ...
user avatar
  • 5,704
63 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 ...
user avatar
  • 8,156
63 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 ...
user avatar
  • 2,905
60 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 ...
user avatar
  • 5,647
50 votes

Why doesn’t my VGA-to-HDMI converter work with my 286 PC?

The manual says that the smallest resolution it can handle is 800x600. That is almost certainly the key. Original VGA supported 640x480 16-colors and 720x400 (essentially a small step up from the ...
user avatar
45 votes

Why does the Commodore C128 perform poorly when running CP/M?

(2017.03.03) I have added a second answer with diagrams and more technical details. This answer is already huge and self-contained; the other focuses on the complexities due to hardware. Why does the ...
user avatar
  • 8,156
43 votes

Is this an Amiga? If so, which model?

I'm trying to identify what kind of machine this is. It looks like an Amiga of some kind, It's a Commodore C64-II also known as C64C: The mouse seams to be an Apple ADB mouse (Type A9M0331), sold ...
user avatar
  • 173k
42 votes
Accepted

What precautions to take when powering on old computer for the first time in years

There are several simple precautions that are always worth taking when powering up a vintage microcomputer after long periods of storage or non-use. The minimum, simple steps, should include: Place ...
user avatar
  • 57.3k
38 votes

Why did the stock Amigas not have a battery for keeping the time/date?

You specifically mention the Amiga 1200 in your question, but your statement about real-time clocks is not true for Amigas, in general. From 1987, the Amiga was offered in at least two versions aimed ...
user avatar
  • 57.3k
35 votes
Accepted

Why did Commodore sell CPUs to its competitors?

The 6502 was designed and manufactured before Commodore bought MOS Technology, the creator of the 6502. MOS Technology didn't originally plan to build computers. They wanted to sell the 6502 to ...
user avatar
  • 4,396
31 votes
Accepted

Why does the Commodore C128 perform poorly when running CP/M?

I'm Linards Ticmanis, the guy who put out the CPMFAST package in 1999 that has been mentioned several times in the other answers (although I go by the nickname TeaRex on here). While creating that, I ...
user avatar
  • 1,055
30 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 ...
user avatar
29 votes
Accepted

Why was IBM BASIC so Huge?

The early versions of Microsoft BASIC required 4KB of ROM The 4k versions lacked a number of major features, including string variables. These were added in the 8k versions. The equivalent 6502 ...
user avatar
25 votes
Accepted

What is the difference between the Commodore 1701 and the 1702?

The 1701 and 1702 are virtually identical. They have the same specs, tube, inputs, casing, and manufacturer. The only real difference is the 1701 is older (1982 to early '83, 1702 is late '83) and the ...
user avatar
  • 4,052
25 votes
Accepted

Which 8-bit computers were used in German schools in the 1980s?

Which brand was most commonly used in West German schools? I know Commodore was big in Germany, which would make it a likely candidate, unless nationalistic pressure acted again? There is no simple ...
user avatar
  • 173k
25 votes

Why doesn’t my VGA-to-HDMI converter work with my 286 PC?

DOS is almost surely not outputting 800x600 or up, and is probably in the ballpark of 720x350 or thereabouts. Further, it's likely 70Hz, which this adapter may not like. I'd recommend you get a ...
user avatar
23 votes
Accepted

Are pixels on the Commodore 64 square?

The pixels are not exactly square, the actual aspect ratio depends on the TV system. For PAL-B, the pixel aspect ratio is 0.937:1, the pixels are a bit higher than they are wide. For NTSC, the ratio ...
user avatar
  • 4,090
23 votes
Accepted

How did Commodore drives produce program listings from disk directories?

TL;DR: The computer, or rather its OS, has no idea about a directory, in fact not even what constructs a file. It can only open/read/write/close data streams from devices on the bus. Getting a ...
user avatar
  • 173k
22 votes

Why did Commodore fill their power supplies with epoxy?

Electricians some times (or used to) do similar techniques when configuring wiring -- once the wires were in place, they would fill the cavity with a non-conductive resin or epoxy, so that the chance ...
user avatar
  • 321
22 votes
Accepted

Who ended up owning Commodore's semiconductor IP?

TL;DR The ownership issue is really associated with the trademarked brand and product names, and the copyrighted ROM software, not the processor/co-processor hardware. I think there are two ...
user avatar
  • 57.3k
22 votes
Accepted

Is it possible to boot C64/C128 from floppy

On the C64, no. On power up, the drive is resetting and the motor may spin briefly, but the drive is not actually reading the disk. And even if it were, it is an IEC slave device and cannot initiate ...
user avatar
  • 4,348
20 votes
Accepted

Amiga floppy disks and GCR vs MFM

On a floppy disk, each 'bit' is a flux reversal — a magnetic event. If those bits are too close together, they'll leak into one another and data will be lost. Disk controllers use a regular clock and ...
user avatar
  • 32.5k
20 votes
Accepted

Why does the VICE "load" command skip the first two bytes?

Quote from VICE manual: Load the specified file into memory. If no address is given, the file is loaded to the address specified by the first two bytes read from the file. If address is given, the ...
user avatar
  • 17.9k
20 votes

Commodore Mouse not recognized by a Commodore PC30-III 286 machine

Since your mouse has three buttons, it won’t use the same protocol as Microsoft mice (at least, in three-button mode), and won’t be fully supported by the Microsoft driver. Presumably the mouse was ...
user avatar
  • 96.5k
19 votes
Accepted

Why was it not possible to cost-reduce the Amiga 500?

'Jeff Porter realized it would not be possible to significantly cost reduce the Amiga 500 to get it into the $250 retail price range'. They could have cost-reduced the A500 - perhaps even to $250 ...
user avatar
  • 5,813
18 votes

Why does the Commodore C128 perform poorly when running CP/M?

My first answer attempts to answer all the OP's questions without going too deep into the hardware details. Since posting that answer, I have had the pleasure of corresponding for several days with ...
user avatar
  • 8,156
18 votes
Accepted

Commodore BASIC and binary floating point precision

This example reveals a rounding error under Commodore BASIC V2.0: A=0.3:B=0.6:IF A+B<>0.9 THEN PRINT A+B-0.9 Running this on a C64 yields a difference of 2.32830644e-10. Other pairs that ...
user avatar
  • 4,090
18 votes

Did the Commodore datasette interface provide greater reliability?

The Datassette has a digital interface, and since it is not meant to process audio signals at all, it allows directly writing sharp digital magnetic transitions to the tape, using a single monophonic ...
user avatar
  • 17.9k
17 votes

Are pixels on the Commodore 64 square?

In standard bitmap mode the C64 outputs 320 pixels in 40µs. The visible portion of a line is ~52µs; in 60Hz regions ~240 lines are considered 'visible', but in PAL regions it's ~288 lines. So if ...
user avatar
  • 32.5k
17 votes
Accepted

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

Space on a chip die was very limited - you couldn't just put an unlimited amount of functionality into one chip. If you have a closer look at video chips used in 8 bit computers, they either feature ...
user avatar
  • 1,389

Only top scored, non community-wiki answers of a minimum length are eligible