Further Expansion

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GreyGhost
Vic 20 Nerd
Posts: 525
Joined: Wed Oct 05, 2005 11:10 pm

Further Expansion

Post by GreyGhost »

With Ultimem coming out(got mine the other day. Woot!), I have been thinking about other ways the Vic could be expanded. Is there no way to map the character ROM? My thoughts led me to the idea of an internal expansion card at the character ROM slot itself. Something that held the char ROM and 4k of RAM. The Character ROM being mirrored to the RAM at startup but then, being RAM, could be changed to whatever we wanted... new fonts, game characters, bit maps, whatever. This area is seen by the VIC chip and could hold 2 character sets(or one double height) as it does now. One issue I've thought of would be at start up with the Vic seeing a continuation of memory on a fully expanded machine and allocating it to be used for BASIC. Any thoughts on this? Could it be done?
Rob
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TLovskog
Vic 20 Enthusiast
Posts: 194
Joined: Fri Mar 25, 2011 3:16 pm
Location: Kävlinge, Sweden

Re: Further Expansion

Post by TLovskog »

Hi,

That is absolutely possible. My projects go very slowly, but my internal GCart was meant to handle they, including a mode where RAM at the character rom is available for program and BASIC as well. Plus s few other ideas.

But it is much thought, tests, and theory so far. Although I have done a first board spin.

http://wordpress.lovskog.eu/projects/20 ... k-is-that/
BR
Thomas Lövskog
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