On 2012-07-20 09:16, Segher Boessenkool wrote: > We also know that all of the pad/drivers stuff is redone for HMOS: it > has to be much bigger relative to the core logic; you can see this on > e.g. the SID and VIC-II chips. > ... > Oh, and 7501... :-) The 7501 shows that the transition must have happened in a slightly more complicated path than a supposed upgrade of the 6510 to HMOS-II, and the derivation of both the 8501 and 8502 from that design. The 7501 obviously precedes the 8500. Unless there had been a never marketed 7500, the first HMOS (HMOS-I) 6502 descendant must have been the 7501. Of course, the question still remains whether they upgraded the 7501 to HMOS-II later, and derived the 8500 and 8502 designs from that, or moved the NMOS 6510 to HMOS-II, and derived the 8501 from that once again. (Or they just copypasted/resized parts between NMOS/HMOS-I/HMOS-II layouts all over just as they needed; as I understand, the "conversion" between different NMOS designs isn't very complicated, and differences between the 8500/8501/8502 layouts are very subtle). Levente Message was sent through the cbm-hackers mailing listReceived on 2012-07-22 09:00:06
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