Questions tagged [commodore]

For quesitons regarding Commodore Business Machines itself or its products that do not have a more specific tag such as commodore-64 or amiga.

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10
votes
2answers
794 views

Did all integrated Commodore PET monitors always use 60 Hz refresh?

All models of the Commodore PET line had built-in monitors, and at least the U.S. models had 60 Hz refresh. For the European models there was no need for compatibility with European television ...
4
votes
2answers
270 views

Commodore monitor to VGA or HDMI

I have this monitor, which I think is a Commodore 64 monitor. I would like to connect it to a pc. Anyone know how to convert VGA or HDMI to this connector format? I've tried searching, but so far I'...
2
votes
1answer
148 views

What were Commodore's keyboard layouts before the VIC-20?

Starting in 1980 the VIC-20 keyboard seems to have become sort of a standard for Commmodore, being re-used on the MAX Machine (in membrane form), C64, C16 and (with additional keys added) the 128. ...
5
votes
2answers
396 views

How do I adjust the OS print output to different screen dimensions on VIC-20?

The graphics chip of the VIC-20 has a setting for the number of columns and the number of rows to display. So, instead of the default values of 22 columns and 23 rows, for example, it is possible to ...
9
votes
2answers
412 views

How do you send code to a Commodore disk drive and run it?

Commodore disk drives such as the 1541 used with the Commodore 64 and similar computers, and the earlier 8050 used with the PET series, had their own 6502 CPU and 2 kB or so of RAM used to run the ...
11
votes
1answer
707 views

Does the Commodore CDTV-CR contain a 65C02 for some reason?

Browsing around the FS-UAE source code I discovered a 65(S)C02 emulation core, which appears to not be referenced anywhere outside of some CDTV-CR related source file. Apparently, a CDTV is ...
10
votes
3answers
288 views

Commodore 64 with partly working keyboard (part 2)

I have a C64 that has recently stopped responding to two 'columns' of keys, namely '9,0' 'i,o' 'j,k' and 'n,m' - I've swapped the CIA chips (U1 and U2) to no effect, so I pulled a keyboard from a ...
6
votes
1answer
221 views

Digital PCB Plans for Retro Computers

I use software like Fritzing or Autodesk EAGLE to draw my Raspberry Pi or Arduino projects and was wondering if there is a source for PCB plans of for example an Amiga 500 in a format readable for ...
3
votes
1answer
129 views

How to write directly to the Commodore 64 (or similar) DAC [duplicate]

I read some related information in a SAM question but I want to know exactly how to write amplitudes directly to the DAC, sample by sample, like in a bytebeat formula. I understand it is possible on ...
5
votes
2answers
422 views

Did any devices use the Commodore 64 joystick ports as outputs or two-way communications ports?

Looking at the schematic and explanation of how the C64 joystick ports work, it seems clear that the stick direction and button lines (JOYA0, through JOYA3 for port 1 and JOYB0, through JOYB3 for port ...
17
votes
2answers
1k views

What was the role of Commodore-West Germany?

Most of the history of Commodore in personal computers took place while East and West Germany were divided, and Commodore maintained a significant corporate presence in West Germany. While I believe ...
7
votes
4answers
486 views

How is PETSCII used by assembly-language programs?

First, a bit of context. I wrote an interactive disassembler for 6502 code that, among other things, attempts to identify ASCII strings automatically. Appropriate source code for different assemblers ...
4
votes
1answer
147 views

Was there any VIC-20 expansion to bring memory beyond the default maximum of 40 KiB?

The Commodore 64 was very flexible in terms of how RAM could be controlled. ROMs and I/O devices could easily be swapped out by setting bits in the first two addresses of memory. The VIC-20's ROMs and ...
9
votes
3answers
1k views

What is the best option to connect old computer to modern TV

I was exploring different options of connecting both my Atari ST and C64 to a modern TV. I opted for a composite signal passed through a cheap AV to VGA converter, and although the display works, ...
5
votes
0answers
249 views

Does the Commodore 64 power switch have a history of failing?

My original (1983?) Commodore 64 (brown breadbox with grey function keys) has trouble powering on. Specifically, when I flip the power switch the power LED will glow dimly and the machine fails to ...
7
votes
2answers
454 views

How advanced was the Amiga Walker prototype?

The Amiga Walker was a prototype Amiga computer that never made it to market. Wikipedia has some info including a photo of a motherboard. How advanced was the prototype? Could it boot and run Amiga ...
4
votes
0answers
124 views

Vic-20 total game cartridge sales

The Vic-20, like many home computers of its time, had a cartridge slot that could be used both as a general expansion slot, and for game cartridges like a console. Game cartridges on the Commodore ...
2
votes
1answer
229 views

Commodore PC-1 power supply measurements off

I have a Commodore PC-1 with a busted power supply. I have no desire to fix it as I don't have the know-how it is already 30 years old It is difficult to debug / find replacement components So I ...
3
votes
1answer
252 views

First Commodore 80-column monitor

While the Amiga could be used with a TV in a pinch, it was primarily intended for use with an RGBA monitor; memory says, and Google seems to confirm, that was the 1084. Commodore made color monitors ...
5
votes
1answer
352 views

Commodore Plus/4 60671 bytes free - how?

It is widely known that, while the Commodore 64 did indeed provide 64K of RAM for machine code programs, only 38K was usable from BASIC; this was because bank switching was needed to get at the rest, ...
17
votes
4answers
1k views

Commodore BASIC and binary floating point precision

I am mildly curious that though the 6502 provides BCD arithmetic which would be useful for implementing decimal floating point, Commodore BASIC uses, like all (?) Micro-Soft BASIC, binary floating ...
8
votes
4answers
732 views

Amiga floppy disks and GCR vs MFM

According to https://en.wikipedia.org/wiki/Group_coded_recording the Commodore 1541 disk drive used a particularly efficient GCR encoding scheme to cram 170K onto the same 5.25" disks that in an Apple ...
5
votes
2answers
385 views

C116 vs C64 cost

The Commodore 116 was the start of the ill-fated TED line of 8-bit computers, which sold poorly (for several reasons, particularly including lack of compatibility with the Commodore 64) until they ...
1
vote
0answers
121 views

Old C128 - normal to straight away pull 2 amps? [closed]

I'm trying to get an old C128 working again. Lacking a C128 power supply, I've attached a C64's power supply's 9VAC and am supplying 5VDC from a bench power supply (with a 2A limit at the moment). ...
9
votes
1answer
348 views

Possible cause for C128 A/V output containing faintly coloured columns and failing shortly after?

I recently acquired a Commodore 128. It worked fine for about an hour, in both C64 and C128 mode, at the exception of some coloured bars, before displaying garbage and not booting anymore into any ...
8
votes
0answers
375 views

How many Amiga 3000's were produced?

While revisiting this question: Seeking details relating to Amiga 3000 serial numbers I began to wonder how many actual Amiga 3000's were produced by Commodore. I suspect (like most production ...
9
votes
2answers
924 views

What is an “unused” memory address?

Reading this page on Commodore 64 memory structure and usage I stumbled across a cell where the table claims that this memory is unused. What exactly does this entail? Does this mean that if you ...
3
votes
0answers
255 views

Commodore C128 MOS 6526A interchangeability?

I have a working C128 desktop that I'm using to troubleshoot a non-working C128D-CR. I suspected a problem with CIA 2 on the C128D, so I swapped its chip labelled "6526A" with a 1988 year stamp with ...
5
votes
3answers
409 views

Commodore 8-bit character sets

Is the character set format same on every Commodore 8-bit computer or are there any character size, character order, or other differences between the machines? I'm purely interested in the character ...
6
votes
1answer
370 views

Commodore-Motorola lawsuit in 1984

According to Commodore: The Amiga Years, the reason the Commodore UNIX machine project in the early 80s used the Z8000 rather than the 68000 was an ongoing lawsuit with Motorola: With the Commodore-...
2
votes
1answer
216 views

TED computers and delayed RAM chips

From 'A Company on the Edge', page 545: Commodore marketing scheduled the release of the TED computers for May 1984, but met with inevitable delays due to RAM shortages and problems with the ...
3
votes
1answer
261 views

Transatlantic gray market Commodore PETs and 220V/50Hz vs. 115/60Hz

In the late seventies, Commodore sold the PET in Europe at a considerably higher price than in America; they could get away with this because there was less competition there. Some of the American ...
11
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6answers
1k views

Part-bad chips other than RAM

In the early eighties, you could buy half-bad 64k RAM chips at a discount. Some cost-conscious manufacturers such as Sinclair and Tandy took advantage of this, buying eight such chips to make a 32K ...
6
votes
1answer
251 views

When did MOS Technology upgrade to 5µm?

I'm trying to understand exactly why various chips were designed the way they were at different times, in the service of which I have a rather specific question: When did MOS Technology upgrade to ...
9
votes
4answers
754 views

Early BASIC memory management

Can anyone verify or correct my memory here? Long ago, I had access to a Commodore PET which I think had 8kB of memory. Also slightly less long ago, I had a Commodore 64 with its "elephatine" 64kB. ...
8
votes
2answers
747 views

Is it possible to bank out Kernal in Commodore PET, VIC-20 or 264 series computers?

You can bank out Kernal ROM in C64 using $01 register. This was preferred by game/demo coders who wants to employ self tuned routines and wants to expose ram 'underneath'. You can do lda #$35 : sta $...
8
votes
4answers
1k views

Were external floppy drives for Atari ST and Amiga inter-compatible?

Were external floppy drives for Atari ST and Amiga inter-compatible? For example, Commodore 1541* had its own serial bus protocol. But what about the external 3.5" DD floppy disk drive on 23pins D-...
8
votes
3answers
1k views

How to spin up 1541 drive without C64

I have a 1541 drive and I want to make it spin but I don’t have a Commodore computer. I don’t need to read data, I would just like the drive to spin. Can I manually tell it to spin using a raspberry ...
6
votes
4answers
613 views

What was the 2nd best selling computer ever? [closed]

It's widely known that the Commodore 64 was the best-selling single model of personal computer. Which computer make & model got second place? To clarify, I'm looking for an objective answer about ...
6
votes
2answers
477 views

Why did Commodore files not include metadata to say where in memory to load it?

On the Commodore 64, (and I believe also the VIC-20, PETs etc.) you may instruct BASIC to LOAD "something",8 to load a file to the start of BASIC's area (and that address may vary between machines),...
6
votes
3answers
504 views

Commodore VIC-20/64/128/16/Plus 4 floppy disk drive replacement

We all know that floppy disks are getting hard to find, and floppy drives are fragile to begin with (especially Commodore's 1541 drive). I know that several companies and parties have released floppy ...
6
votes
3answers
1k views

Getting your Commodore VIC-20, 64 or 128 online

Back in the day, of course we used modems ("dial-up modems" in today's parlance) to get our Commodores connected to other systems. These days I know several people have concocted options to get ...
1
vote
1answer
510 views

Amiga versus Atari ST computer introductions [closed]

I'm interested in the time, place and manner in which some historically important computers were introduced to the world. For example, the Macintosh was presented in January 1984 by Steve Jobs, first ...
5
votes
7answers
1k views

Benchmark between Home computers? What can be a valid parameter for that?

I'm writing my thesis about the home computer market between 1977 and 1984 (focusing on Commodore Inc.so PET, VIC-20 and 64 and competitors). I'm trying to plot a curve describing the technological ...
27
votes
5answers
5k views

Why did Commodore sell CPUs to its competitors?

Many of the most popular personal computers and video game consoles of the 1970s and 1980s, including those made by Commodore, Apple, and Atari, used the 6502 CPU (or some close relative, such as the ...
13
votes
1answer
520 views

Where are the blueprints of MOS chips?

Atari historians have been able to find documents and tapes of chips and hardware developed at Atari. E.g. http://atariage.com/forums/topic/154479-new-gtia-chips/ . Nothing like this is happening ...
9
votes
1answer
1k views

What is this extra lead in my monitor cable?

I have a breadbox Commodore 64 with a Commodore 1702 monitor. My monitor has three RCA-style inputs on the back: Audio (White) Luma (Yellow) Chroma (Red) I purchased a cable which claims to be an ...
51
votes
2answers
10k 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 ...
107
votes
2answers
18k views

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 ...
9
votes
1answer
2k views

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

Among the monitors offered by Commodore were the 1701 and the 1702, which, to my recollection, looked pretty much identical. Were there any cosmetic, functional, or other differences between the two?