We made the original 7501/8501 with a 6510 and a 74ls74 on a small tower, there wasn't a dependency on the excat mapping of the I/O p[ort at the time, but should be something you can put together. Bil Herd -----Original Message----- From: firstname.lastname@example.org [mailto:email@example.com] On Behalf Of Ruud@Baltissen.org Sent: Saturday, August 13, 2011 12:23 PM To: firstname.lastname@example.org Subject: Re: 264 Series and their chips Hallo Gerrit, Have you ever thought about replacing the 8501 with a 8502 from a C128? So far I found four differences: - the 8501 has this MUX input (or output? I have no idea what it does) which the C128 lacks - the 8502 has an "extra" NMI input compared to the 8501 - the 8501 lacks the P5 I/O pin, the 8502 P7 - pinout doesn't match If the MUX gate doesn't spoil things, what about using the 8502? Regarding P5/P7: you either don't use the cassette recorder anymore or adjust the bits of the Kernal. Just my two cents... -- ___ / __|__ / / |_/ Groetjes, Ruud Baltissen \ \__|_\ \___| http://Ruud.C64.org Message was sent through the cbm-hackers mailing list Message was sent through the cbm-hackers mailing listReceived on 2011-08-14 18:00:24
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