ncoplin@orbeng.com wrote: > But how to do some of the other devices work: > > RAMLINK (in particular where does RLDOS live)?? I'm sure it is mostly a kernal replacement that lives at $e000 and uses Ultimax mode to map into the C64. This is why it needs the extra cable attached to the HIRAM signal in the C64 to allow access to RAM at $e000. I have no idea where it maps the rest of its ROM when needed, but it can be everywhere from $1000-$ffff. I can't check it, because all I have is a broken, non-working RAMLINK board. Some GALs seem to be dead :-( > Epyx FastLoad (there's only a ROM and logic here)?? There once was a thread in comp.sys.cbm about this cartridge, called "epyx fastload internals" or something like that. I think parts of the ROM are mapped into I/O space, and accesses to I/O space trigger a circuit that maps in ROML for a certain time. After a timeout the ROM vanishes again. Quite tricky :-) > Action Replay (EPROMS, RAM and Logic)?? The AR is very well understood, there are even docs on funet to make your own clone. Another very good source for cartridge information is the source code of the VICE emulator. > How do the C128 carts do it? Nothing special, I guess. Without any extra circuit the 128 can address 32k ROM on an expansion port card (minus some bytes for MMU addresses). Nicolas - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi.
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