Commodore.ca: The PET, VIC, 128, 64 & More Forum

How would like it if you never had to plug in a ram expander into your VIC 20? How would you like to have a single memory map, where the screen and color memory don’t change location on you? How would you like to easily change the code in your kernel or basic operating system, by copying the ROMs to RAM that is hidden beneath the ROMs, just like on the C64? How about a bitmap screen that doesn’t take away from basic programming space? How about 31231 Bytes free when you turn on your VIC 20? How about an extra bank of 50K of memory to use for programming or storage with a total of 110K of memory? All of this is possible when you transform your VIC 20 with this hardware addition.

I have a working system (not for sale), but will gladly share the info on how to build one yourself...not for profit.

That sounds very interesting. I am surprised at the lack of responses. Perhaps people think this is too good to be true. You might want to post some pictures and more detail.

Thanks for the information

This sounds amazing.

Some pictures of the screen and performance improvements would get this post some star status.

Thanks for sharing.

This is a real VIC 20. I have built this with a later model VIC using the brick style power supply that also works with the C64. Although it should also be possible to do this with an early style VIC. This modification does not improve the performance of the VIC 20 in any way, but it does open up a lot of possibilities to the programmer. You could have a much larger bitmap for graphics, even bitmap buffering and page swapping, or a GEOS style operating system could be developed on the VIC 20. I have a modified version of the "Fast Assembler", which was published in an issue of Compute's Gazzette, (May 1986 I believe), that works on this modified VIC. This project is not for the newbie that has never picked up a soldering pencil before and you must be able to trace some of the circuitry on the VIC 20 board and cut traces, but it's all worth it. So give it a shot and enjoy the benefits. I would be happy to post pics, but I don't have a URL for them, so email me and I will send pics.

The circuitry is all built with off the shelf components.