Surprising Hack: Use a Commodore VIC20 to fix Commodore PET
ฝัง
- เผยแพร่เมื่อ 16 ก.ย. 2024
- Using an older version of the Commodore VIC20 computer to fix a Commodore PET computer? Yes!! There are several chips that are used in both computers. Let's have a look at them.
MOS 6522 VIA (Versatile Interface Adapter) - I\O control like keyboard and ports. The MOS Technology 6522 chip was used in the Commodore PET for peripheral I/O, The 6522 was used for interfacing with the keyboard, cassette tape, and other peripherals The 6522 was also used in the Commodore VIC-20 for peripheral I/O. The VIC-20 has two 6522 chips, one of which is used for the keyboard matrix and the other for joysticks, various ports, etc.
2114 - RAM
The first version of the Commodore PET 2001-8 used MPS6540 ROM chips and MPS6550 RAM chips. Later versions substituted 2316B ROM chips in place of the 6540’s and/or 2114 RAMs in place of the 6550s
MOS 6502 - CPU (Central Processing Unit) executed at 1Mhz
* Can also get the 6502 and 6522s from a Commodore 1541 floppy drive *
Here are PET assemblies that use the 2114 RAM chips for the video RAM.
Dynamic PET
Assembly #8032029 2114 is used for video RAM.
Dynamic PET 80 Column that uses 2114 RAM for video RAM
Assembly #8032030-01 80 Column Dynamic PET 32K,
Assembly #8032030-02 80 Column Dynamic PET 16k,
Assembly #8032030-03 80 Column Dynamic PET 16k,
Assembly #8032030-04 80 Column Dynamic PET 16k,
Assembly #8032030-05 80 Column Dynamic PET 16k,
Assembly #8032030-06 80 Column Dynamic PET 16k,
Assembly #8032087
Universal Dynamic PET that uses 2114 RAM for video RAM
Assembly #8032090-01 8032-60Hz PET 32K,
Assembly #8032090-02 8032-50Hz PET 32K,
Assembly #8032090-03 4032-60Hz PET 32K,
Assembly #8032090-04 4032-50Hz PET 32K,
Assembly #8032090-05 4016-60Hz PET 16K,
Assembly #8032090-06 4016-50Hz PET 16K,
* 2114 static RAM is always used for video RAM on all PETs, except the first two boards from 1977 that used 6550.
* 2K of video RAM (4 chips) for 80 column PETs and 1K (2 chips) for all others.
* The 2001-N Dynamic PET could be reconfigured with jumpers for different types of DRAM chips and different amounts of DRAM.
I hope you enjoyed this video and learned something new and happy repairs!
Thanks all the subscribers and viewers like you!
Big thanks to these Patreon members!
Dave Vintage Apple Tech
/ channel
Jamie's Hack Shack
/ @jamieshackshack
RavenWolf Retro Tech
www.youtube.co...
Rudy's Retro Intel email: retrointeldiy@gmail.com
For more vintage computer information, check out my GitHub: github.com/Rud...
Help support this channel. Patreon Page - patreon.com/us...
Intro and outro music for Rudy's Retro Intel (full copyrights) granted by:
Thano Productions Inc.
email: thanopapastamoulis@gmail.com
Thanks again for watching!
Rudy
Commodore PET repairs
Troubleshooting
Commodore PET parts
Commodore pet 2001-8
world of commodore
Nice video Rudy. Thanks for the heads up. Now you kept me thinking how different computers would math regarding parts... I guess I'll go for horribly broken computers for scavenging more often.
I'm always on the lookout for dead vintage computers. Parts are good. Thanks for commenting
This is some great info Ruuddyy! Thanks for sharing!!
Hey Frankkk! Thank you, and I hope everyone finds it useful. Thanks for commenting
Great info Rudy
Thanks! Trying to help others. Thanks for commenting
I've been watching "The Clueless Engineer" repair a VIC-20 lately (he's up to part 4) and also replacing the 6522s, the 6502, and ROKLM chips with modern equivalents (with adapter PCBs) to reduce the heat produced inside the computer *and* to lower the power consumption, thus taking less of a strain on the power supply. I'm thinking this approach would be a good idea for Commodore PETs and other vintage computers to increase their longevity. We are keeping these computers alive for posterity, aren't we?
Yes, indeed we are. Modern replacements that reduce energy are always great. It would make for an interesting video to use them inside a PET. Thanks for sharing and commenting
To calm potential haters, it’s not like you have to just use the VIC20 for only parts. You can use them to diagnose what’s wrong and then once you know the true fault, you can source replacements.
Exactly!! Thanks for sharing and commenting
Unfortunately my VIC-20 is in great working order BUT since it works, I can use it for a chip tester for my PET!
Yes, you can! If you ever come across a bad vic20, then get it. Thanks for sharing and commenting
Just a quick comment, disk drive 1541 can also be used on the vic20 (not only c64).
True, even the VIC1541 will work on C64. It's interesting how that works. Thanks for commenting