Questions tagged [commodore]
Commodore Business Machines and their products. Use more specific tags like [commodore-64] or [amiga] instead if appropriate.
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What can be done with a USR file on the Commodore 1541 disk drive?
The USR filetype on the Commodore VC 1541 disk drive is a less common sequential file that according to some book sources can be executed as a program directly on the drive. The drive has its own 6502 ...
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Commodore 64 - any way to safely plug in a cartridge when the power is on?
Back in the early 1980s when my friends and I all had Commodore 64s, we all knew never to plug a cartridge in with the power on.
I once got a tape from someone with lots of utility programmes, one of ...
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Name of Commodore tape format?
How did Commodore call their tape format, if there ever was a specific name for it?
OK, let me clarify. I would be interested in the technical term of the encoding as well as any specific name, should ...
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Sending DOS commands in assembly on my C64
Consider the following Basic program for the C64.
10 OPEN 15,8,15
20 PRINT#15, "I"
30 CLOSE 15
This classic gem simply opens the 'command channel' and sends the DOS 'init' command to the ...
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What is this unusual syntax for the Commodore SYS command?
I was recently interested in how to 'bload' some data on my commodore 64. For the sake of discussion the data isn't really relevant (it could be any blob of bytes).
Generally you can load a file into ...
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Is there a version of Python that runs on a QL, Speccy or a Commodore?
Does any Python port run on any Speccies or Commodores? I am hopeful about QL, since:
Based on a Motorola 68008 processor clocked at 7.5 MHz, the QL
included 128 KB of RAM, which was officially ...
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Correct voltages and current draw for Commodore PC-1
I am fixing a Commodore PC-1 PSU for a friend and want to know if the PSU is behaving as expected. No modern PSU suggestions (e.g. Meanwell), if you don't mind! :)
Question: What are the voltage ...
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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 ...
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1
answer
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Converting CGA (from Commodore PC40) to RetroTink 5X?
I am quite new to the CGA world but I recently got hold on a Commodore PC40-01 desktop computer. This has a CGA card but how to connect this to my RetroTink 5X-Pro, so I can get it to be displayed on ...
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What was the release date of the MOS 8502?
I have been unable to find when the MOS 8502 was first released to customers. The process it was made on was available from 1979, but MOS don't appear to have used it for their own parts at that time.
...
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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 ...
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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'...
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Who ended up owning Commodore's semiconductor IP?
The question of ownership of Amiga-related intellectual property post-Commodore is famously difficult to answer. My question is: does anyone "own" Commodore's semiconductor IP now, and if so,...
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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 ...
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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?
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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 ...
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Why was IBM BASIC so Huge?
The early versions of Microsoft BASIC required 4KB of ROM, and many versions existed in the 8KB and 16KB size. But Microsoft's IBM BASIC (known as "Cassette BASIC") for the original IBM PC (Model 5150)...
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Can two single Commodore disk drives emulate a dual disk drive?
The floppy disk drives manufactured for Commodore 8-bit computers (by Commodore itself and by various third parties) are either single-drive units, or dual-drive units where two disk drives share the ...
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How to properly convert an active-low joystick routine to active-high
My last question wasn't specific enough so I'll rephrase it. I've been having trouble with programming game consoles/computers like Commodore 64 that have active-low joysticks, where the bits are all ...
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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 ...
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What are the safest temporary zero-page locations across all Commodore (CBM) machines?
I have some 6502 machine-language routines that I'd like to be as portable as possible across all, or as many as possible, Commodore 8-bit machines, including the PET (BASIC 1.0, 2.0, 4.0), VIC-20 and ...
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Can powering on/off a 1541 damage a disk left inside?
The User's Guide for the Commodore 1541 disk drive includes a vague warning, on page 7, to "remember to always remove the diskette before the drive is turned off or on". Some third-party ...
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How was "GEOS" meant to be pronounced?
GEOS was a hugely popular operating environment for 8-bit Commodore and Apple machines. It was developed and published by Berkeley Softworks, who eventually released a 16-bit version for IBM-...
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Why doesn’t my VGA-to-HDMI converter work with my 286 PC?
I have a Commodore PC 30-III with a Cirrus ISA VGA card in it.
I wanted to connect to an HDMI display by using a mini VGA-to-HDMI converter
The converter doesn't generate any output. The machine ...
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Why didn't the original Commodore PET computer use a standard typewriter style keyboard?
Being a huge fan of Commodore, I've often wondered why Commodore would use such a horrible keyboard layout for their premier computer utilizing an alpha-numeric keyboard. My only guesses would be ...
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Did Commodore ever produce gray colored Commodore 64?
The Commodore 64 was produced for a 12 years from 1982 to 1994. It had several iterations of case color, keyboard color & keyboard labels, badge etc.
Commodore was famous for using whatever parts ...
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Why was Paperback Writer renamed to Pocket Writer?
I was a big fan of Digital Solutions Inc.'s Paperback Software, a Commodore 64/128 productivity suite that featured an interoperable word processor (Paperback Writer), spreadsheet (Paperback Planner), ...
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Why did the stock Amigas not have a battery for keeping the time/date?
The Amiga computers were advanced machines meant to do all sorts of things, including file management. They had a GUI OS (Workbench) and everything right from the very start. They were not some games-...
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Amiga floppy disks and GCR vs MFM
According to the Wikipedia article on GCR, 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 drive only ...
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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 ...
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Commodore Mouse not recognized by a Commodore PC30-III 286 machine
I have Commodore PC 30-III 286 machine with a serial port at the back labelled "mouse". If I plug my Commodore mouse 1900 serial mouse then execute mouse.com at the DOS prompt then I get the ...
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Commodore C386SX-LT, what is causing this hissing sound
I'm trying to work out what is wrong with this laptop. There is a hissing sound coming from the power board mid left. The laptop screen remains off and there is no output to external VGA unless it ...
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How did Commodore drives produce program listings from disk directories?
CBM BASIC 2.0 has no built-in command for listing the contents of a floppy disk. Instead, the usual way is to LOAD a pseudo-file named $ from the disk into memory. The file can then be LISTed like a ...
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Commodore 1581 crashes during format
I have a Commodore 1581 (800k 3.5" DD) floppy drive which reads and writes data just fine (with DD disks only of course), but it crashes (drive keeps spinning forever, stops moving the head and ...
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Commodore 1352 mouse converter
My Commodore PC30-III can only handle a Commodore 1352 mouse, but it is practically impossible to buy one. I own a couple of Amiga and serial PC mice that if I plug in, the buttons seem to work, but ...
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Is solder-on memory upgrade an option here and how to check it
I have this system with 2MB onboard RAM, but I noticed there are additional soldering pads to the right from memory chips (NEC 424400-80L, but there are also TOSHIBAs TC511664JL-10 on daughter board ...
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Which early computer games supported "English" from the paddle controller?
In relation to this answer about the "English" control of the Magnavox Odyssey, I am wondering if the concept found its way into other games for later computers and consoles that supported ...
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What's the timeline of Commodore diskette drives?
Commodore produced a number of different floppy diskette drive units, both 8" and 5.25", over the course of its history. Can someone provide a chronological list of the drives, their release dates, ...
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How can I enter BIOS setup on a Commodore PC 30-III?
I have a Commodore PC 30-III but I can't find a way to start the BIOS menu. It displays the following message during startup:
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Why did the Commodore PET 2001 take so long to ship?
In 1976 Commodore as a company had been running for more than twenty
years and had extensive experience with designining and selling
consumer electronics products: they were one of the top-selling
...
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How was end-of-file stored on a Commodore 1541 disk? [duplicate]
On a VIC-20 or C-64, you could open a sequential file on a 1541, write exactly N bytes (say, 47 bytes) to it, then close it. Then you could open the same file for reading and start reading byte by ...
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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 ...
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Why does the VICE "load" command skip the first two bytes?
I am studying assembly of the C64, and of course using VICE to do so. VICE has the load command to load data straight into the C64 RAM. I reckoned I could use that to put machine code into RAM and run ...
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VIC20, VIC-20, or VIC 20?
The 'tag' on this website calls it 'VIC-20', but the VIC20 user manual (Personal Computing on the VIC20) http://cini.classiccmp.org/pdf/Commodore/VIC-20%20User's%20Manual.pdf calls the VIC either ...
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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 ...
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Amiga 500 WorkBench 1.2 Freezes
When I load the Workbench, it loads normally and I can use the mouse to select and open folders and load programs as expected.
What happens is, at random, if I double-click on an icon the icon will ...
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Commodore BASIC: why was the PET's GOTO so slow?
Received wisdom has it that Commodore didn't want to pay Microsoft extra for updated BASIC interpreters, and thus very little changed in Commodore BASIC v2 from the PETs to the C64. But consider the ...
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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 ...
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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 ...
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Is there software that will run across multiple Commodore 8-bit machines without modification?
I noticed in some of the answers in this question that the Commodore 8-bit line apparently used a jump table at $03xx for entry into the kernel ("kernal" for the pedantic) routines. Figuring that the ...
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