RE: 264 Series and their chips

From: Bil Herd <>
Date: Sun, 14 Aug 2011 13:17:41 -0400
Message-ID: <>
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-----
[] On Behalf Of
Sent: Saturday, August 13, 2011 12:23 PM
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...

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Received on 2011-08-14 18:00:24

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