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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8
votes
1answer
169 views

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 ...
19
votes
1answer
2k views

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 ...
8
votes
1answer
756 views

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-...
6
votes
1answer
668 views

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 ...
19
votes
5answers
3k 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 it always felt very "toy" to me because of ...
16
votes
3answers
2k views

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 ...
4
votes
2answers
114 views

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 ...
10
votes
4answers
523 views

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 ...
6
votes
1answer
101 views

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, ...
12
votes
4answers
915 views

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....
1
vote
2answers
152 views

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 ...
4
votes
1answer
183 views

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, ...
4
votes
3answers
295 views

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 ...
7
votes
1answer
196 views

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 ...
10
votes
1answer
699 views

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?
21
votes
1answer
2k views

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,...
12
votes
1answer
4k views

Is this an Amiga? If so, which model?

In the 1998 Swedish comedy musical "Åke från Åstol", there's a moment toward the end when a man is pushing around some sort of Amiga-looking computer with a monitor and mouse on a ...
5
votes
1answer
250 views

Why are the CBM control codes for color setting so spread out?

The control codes (my C64 handbook actually calls them ASCII codes) for color changing on the Commodore 64 are as follows: Color Control Code Color number BLACK $90 0 ...
5
votes
2answers
342 views

Commodore Plus/4 jiffy clock tied to screen refresh frequency? (warning: flashing images)

Warning: There are flashing images below, do not scroll down if you are sensitive to them! According to various sources (for example this for the Plus/4), both the C64 and Plus/4 have a "jiffy&...
5
votes
1answer
250 views

How to get GOTEK to work with CDTV?

I'm trying to connect Gotek drive to my CDTV using external caddy (amitek). The drive has 3 digit LED display, after boot i can see F-F. When I insert Flash drive it detects images on it, I can ...
5
votes
2answers
1k views

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 ...
3
votes
1answer
383 views

Is this real Commodore C386SX-LT

Is the model shown on pictures an authentic Commodore C386SX-LT? Why does it look different to other photos on the Internet (some additional grey keys? above keyboard): http://www.spacereh.de/hc/com/...
8
votes
1answer
612 views

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 ...
8
votes
2answers
825 views

What does Shift-RETURN do on Commodore's 8-bit computers?

Someone recently commented that, "a shift-Return is really different from a normal one. It moves the cursor to the next line, but does not complete an input operation." This would be interesting and ...
6
votes
2answers
452 views

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, ...
18
votes
3answers
4k 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 ...
2
votes
0answers
1k views

How many Amiga 590 units were sold?

The A590 was an external hard disk for the Amiga 500, in 'sidecar' form factor, that could also hold an extra megabyte of RAM. How many 590s were sold, throughout its life?
13
votes
2answers
2k views

Who were the Atari ST designers pilfered from Commodore?

After Jack Tramiel was fired from Commodore and became the owner of Atari, I believe he offered jobs to a number of key technical people who followed him from Commodore. Who were the key people (if ...
0
votes
1answer
212 views

Commodore – The Inside Story [closed]

Commodore – The Inside Story, by David Pleasance, who was a manager in Commodore UK. Sounds like a very interesting book, supposedly available, but when I look on Amazon, hoping in particular for the ...
20
votes
7answers
5k views

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

In the 1980s, each country had a particular brand of computer that was most commonly used in schools; often, there was pressure to go with a local manufacturer. In the US, the Apple II. In Britain, ...
24
votes
3answers
3k views

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

According to 'Commodore: The Final Years' (whole trilogy highly recommended, BTW), page 129, 'Jeff Porter realized it would not be possible to significantly cost reduce the Amiga 500 to get it into ...
22
votes
4answers
6k views

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)...
5
votes
1answer
264 views

Finding replacement LEDs for Commodore gear?

Around 1984, Commodore transitioned from using round LED bulbs for power and drive indicators to rectangular ones. Some of these could be quite wide, like the ones pictured for a 1571 disk drive. They ...
11
votes
2answers
955 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 ...
6
votes
2answers
837 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'...
5
votes
1answer
498 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. ...
7
votes
3answers
580 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 ...
12
votes
3answers
1k 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 ...
14
votes
1answer
933 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 ...
11
votes
3answers
741 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 ...
7
votes
1answer
431 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
245 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 ...
10
votes
4answers
859 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 ...
19
votes
3answers
2k 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 ...
9
votes
4answers
961 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
388 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
2k 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, ...
7
votes
2answers
767 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 ...
9
votes
2answers
675 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
134 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 ...