Am Mittwoch, 18. Oktober 2017, 06:00:09 CEST schrieben Sie: > > El 18 oct 2017, a las 5:45, Jesus Cea <jcea@jcea.es> escribió: > > > > The only option I see is that the 6510 is running a tight loop reading > > commands to read/write those addresses and that the card is releasing the > > DMA briefly when the fast CPU access those location for the 6510 to > > continue execution and simulate the access, but this seems complicated > > and fragile. > The only other option I see is that when the machine boots, the 6510 runs a > ROM in the card that copies basic, kernal and chargen to the card. After > this the card takes control, disable the 6510 via DMA and simulates the > bank switching internally snooping accesses to $0/$1. thats exactly what the existing accelerators do. additionally, when the external CPU writes to its (external) RAM, some DMA mechanism also writes into the C64s RAM, since the VICII can only "see" the internal RAM and else you'd get no picture. -- http://www.hitmen-console.org http://magicdisk.untergrund.net http://www.pokefinder.org http://ar.pokefinder.org Liberals by nature look for information and conservatives look for ammunition. <Al Franken> Message was sent through the cbm-hackers mailing listReceived on 2017-10-18 20:03:39
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