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Welcome to the VIC-20cr Reloaded Project Page! This is a project to create a new VIC-20cr (Cost Reduced) Motherboard which could become a starting point for modified VIC motherboards. For example, we could use a single 32K ram chip and make a VIC-32. We could combine multiple ROMS into a single ROM to save board space, or we could even add extra colour RAM to expand it's graphics capability. We could add a SID chip, or a different video chip, or add a second joystick port.
This project was also created to help me learn Kicad, and to learn how to make custom libraries of Commodore MOS chips that could be used here and in other projects.
Here is the VIC-20cr schematic diagram in Kicad. I made a few small modifications, such as removing the cassette port, and simplifying the power input port. No PCB has been designed as yet:
Here is a variation of a concept for a "VIC-GS" or, VIC Game System. The RAM is increased to 64K (not all usable) in a single skinny-dip SRAM chip to save space. The KERNAL and BASIC have been combined into a single chip. VIC colour memory is also a 64K chip with the upper address lines connected to the user port for FLI graphics. A second joystick has been added as well as normal audio/video RCA jacks. Since this is a "Game System" there would be no keyboard, but I added an external DB-25 port so the Game System can be expanded to a "real computer" ;-) No PCB has been designed as yet:
Kicad was used to enter the schematics. Some small modifications were made, such as removing the cassette port, and modifying the power input. Board layout and routing still need to be done.
2022-05-16: Rich Cini has taken the schematics and used them for his own board design. After a few corrections and modifications he now has a working board! You can find more info on his github here.
Page Created: Sep 8/2016. Last updated: May 18/2022, 1:00pm EST
Send comments or feedback to Steve Gray(sjgray@rogers.com)