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Post by Pinacolada on Dec 13, 2008 18:36:17 GMT -5
I don't know whether this is a totally ridiculous idea, but a C64 can power up and function perfectly fine without a SID chip present. What if one replaced it with a different chip, replacing it into a miniature RAMdisk?
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Post by robertb on Dec 13, 2008 21:17:28 GMT -5
...a C64 can power up and function perfectly fine without a SID chip present. When I had a non-working SX-64, Ray Carlsen replaced the SID chip and had the machine working again. Truly, Robert Bernardo Fresno Commodore User Group videocam.net.au/fcugThe Other Group of Amigoids www.calweb.com/~rabel1/Southern California Commodore/Amiga Network www.sccaners.org/
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draco
New Member
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Post by draco on Jan 4, 2009 7:30:24 GMT -5
A c64/sx64 works without SID chip. But i may not work if a defective sid chip is affecting bus signals.
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Post by Leif Bloomquist on Jan 5, 2009 13:24:33 GMT -5
Nobody is answering Pina's question :-( I'll try though. First, have you heard of the SwinSID? www.swinkels.tvtom.pl/swinsid/It's a plug-in replacement for the SID based on an AVR microcontroller. So it seems you can plug other chips into the SID socket (with suitable pin reassignments) without adverse affects to the C64's operation. So I would guess that you could put a small RAM chip there with a little board to remap the pins. I recall that you can't PEEK the values within the SID though - does anyone know if that's because of the SID's design, or does the PLA prevent it? What you're proposing is almost like using the SID socket as an "option ROM" socket for the C64 (albeit with much more limited addressing space). A fun project would be to use something like the RTC/NVRAM chip I used for my PET a while back. jledger.proboards19.com/index.cgi?board=microhacking&action=display&thread=2381One hitch might be that something (the kernal?) mutes the SID whenever you hit run/stop restore etc. So that would wipe out values in your RAM!
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