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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Amiga 500 left mouse button not working
I've recently bought a Amiga 500 (A6 board). This Amiga works perfectly and starts as it should, except for the fact that when I hover on a icon and click my left mouse button to open it, it doesn't ...
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How to interface with W65C51 UART
I want to build my own computer with retro-ic's. One of those ic's that I want to use is the W65C51 from Western Design Center. I am trying to connect it to a Arduino to learn how to interface with ...
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Commodore 128 bottom row of keys work with different shift keys
I have been playing with a Commodore 128 that I picked up but I have noticed one, what I would call, weird keyboard problem(?).
If I an on the bottom row of the keyboard every other key works with a ...
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Why didn't Commodore run the 6502 at 2 MHz? [closed]
The Atari 800, in 1979, ran the 6502 at 1.79 MHz. That rounds to 2, and was presumably a 6502A rated for 2 MHz, underclocked.
Why did Commodore keep running their 6502 computers at 1 MHz, even the 64 ...
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Why was the 1540 a computer in its own right?
The Commodore 1540 disk drive, along with its better-known successor the 1541, is a computer in its own right, with its own 6502 CPU.
Why was it designed like that?
It adds significant cost to the ...
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The works of Frontier Manufacturing
Having spent the last however many decades believing Commodore Semiconductor Group was a simple rename of MOS Technology, I just watched a video – quite interesting in its own right – which casually ...
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What process node enabled the 6502 to reach 2 MHz? [duplicate]
The original version of the 6502 was rated for 1 MHz, but before the end of the decade, the CPU was available in a 2 MHz version. Presumably what changed was Dennard scaling: make the transistors ...
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What was the RVS key used for on early PCs?
Some Commodore CBM and Sharp MZ-80B keyboards (U.S. version) feature an RVS key, which is linked to an LED on some keyboards (similar to Caps Lock). German CBM keyboards seem to feature a Control key ...
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Seeking information regarding how/when Commodore would refurbish a disk drive
I recently added a Commodore 1581 3.5" floppy disk drive to my collection. Being interested in the history of my new toy, I wondered what I might learn from it's serial number. After some ...
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Where to find datasheets for MOS (Commodore) 85xx chips?
It seems difficult to find any detailed technical information online for the 85xx chips used in later Commodore 8-bit computers. For example, there's an excellent archive at http://www.6502.org/...
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How is the Commodore BASIC RND function seeded, depending on the argument?
In AppleSoft, RND with a negative number performs a seed on the generator with that number. So, as I understand it X=RND(-1) is the equivalent of RANDOMIZE 1:X=RND(1):
If aexpr is positive, returns a ...
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Memory gap in Commodore PET
Most largish programs written for the Commodore PET have a bunch of rem statements somewhere around the 8K or 16K area. The normal comment is something to do with a hole in memory. I remember PET ...
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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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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 ...
- 10.2k
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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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 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 ...
- 805
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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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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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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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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 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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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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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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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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How can I restore the VDC RAM to usable text mode after clearing memory for hi-res graphics?
So, I've got a C-128 with only 16K of VDC video RAM. I've finished my lovely high-resolution graphics routine on the RGBI display and want to exit to BASIC with a functional 80-column text screen, ...
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Did the Commodore datasette interface provide greater reliability?
Cassette, being cheaper than a floppy disk drive, was a popular storage medium in the 8-bit era. Some computers such as the Sinclair Spectrum, just provided a port to plug in an existing cassette deck....
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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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From what errors could Commodore's tape loader recover
The Commodore PET/VIC-20/C64 tape routines write out the leader for each file twice, and then write the data twice. While it would seem that this should allow data to be loaded more reliably, ...
- 38k
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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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Could a double-sided Commodore disk be written to be used as a "flippy" on a 1541, without requiring flipping on a 1571?
Although the 1571 is capable of reading and writing both sides of a disk, accesses to the second side using the second head will be performed with the drive spinning in opposite direction from how it ...
- 38k
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Is it possible to boot C64/C128 from floppy
When powered on 1541 reads the disk for a brief moment. Is it used to boot system from floppy? Is it possible to create a bootable commodore 64 floppy?
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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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