Questions tagged [vic-20]
For questions about the Commodore VIC-20
36 questions
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Why does the VIC-20 tinymon relocator escape $00 bytes?
Jim Butterfields tinymon1 monitor for the VIC-20 was distributed as a BASIC program with appended machine language code, as is typical for many CBM machine-language programs.
However, in this case the ...
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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 ...
- 65.3k
7
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Which computer first used stored characters (shape selector) and character bit patterns in the same memory
On the Commodore VIC-20, the VIC chip alternates between cycles where it fetches a byte from screen memory that identifies a character (and also a nybble from color memory), and cycles where it ...
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VIC 6560, which parts do what?
I'm interested in the design of the VIC, the video and sound chip in the Vic-20. (Not too be confused with the VIC-II, which has been discussed elsewhere on the site.) I haven't been able to find an ...
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Did the Vic-20 save money using static RAM?
The unexpanded Vic-20 had 5K of RAM. This was quite small even by 1981 standards, but it was trying to be cheap enough for consumers to buy, and it succeeded, selling over 2 million units.
One reason ...
- 65.3k
5
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Why does the VIC-20 have its cartridge area at a higher adress than the I/O area?
Why did the designers of the Commodore VIC-20 chose to put the main cartridge ROM area at $A000, beyond the character ROM area at $8000 and the I/O area at $9000? Flipping the two around, with the ROM ...
- 1,188
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Were cartridge slots cheaper at the back?
I'm remembering a difference in the design of Commodore computers like the Vic and 64, versus the Atari 8-bits, and game consoles from the likes of Atari and Nintendo: they all had cartridge slots, ...
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7
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What were VIC-20 year-by-year sales?
From "Commodore VIC-20: Worlds First Computer to Sell 1 Million Units" I see that:
Between early 1981, when the VIC actually hit store shelves, and the first few months of 1985, when the ...
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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 ...
- 270
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Why did the Vic-20 need special chips for I/O?
The Vic-20 used two 6522 VIA chips for I/O. I asked why it had two of them but thanks to a comment from Bruce Abbott, I now think that wasn't quite the question I needed to ask.
What I really need to ...
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Why does the Vic-20 have two VIA chips?
The Vic-20 uses the 6522 VIA for peripheral I/O. However, it has two of them. I find this surprising, particularly considering minimizing cost was an important design goal. Is there a reason why it ...
- 65.3k
5
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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, ...
- 41.2k
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Upping the speed of the VIC-20 tape drive: aftermarket hardware for the expansion port with "rabbit" in the name?
EDIT: I realize from reading the comments that I was bit loose in my use of the word "speed" as a property of the tape drive. What I had in mind was the speed of the data transfer, not the ...
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VIC-20 vs. VC20 (or VC-20)
My first computer was a VC20. Was it just renamed (for the German market?) as a VolksComputer?
(I am a Finn and the VC was bought in Finland). Or were there any actual differences to VIC-20?
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