6501 and 6500/1 (was Re: Revamped Web site up)

From: Eric Smith <eric_at_brouhaha.com>
Date: Fri Nov 6 18:34:47 1998

"Richard A. Cini, Jr." <rcini_at_email.msn.com> wrote:
> None of the data sheets that I have (not even the "family" ones) mention
> a 6501.

The 6501 was very similar to the 6502, except that it was completely pin
and bus compatible with the 6800. The 6502 was an improved version with
a built-in two-phase clock generator, so it only needed a single-phase
clock input, but could not be dropped directly into a 6800 socket.

Motorola was upset with MOS Technology over this, especially since some
of the 6800 designers were working for MOS. Under pressure from Motorola,
MOS dropped the 6501. I'm not sure if this was the result of a judgement,
out-of-court settlement, or just a threatened lawsuit. The 6501 didn't
appear in the later data sheets and manuals.

As I stated previously, the 6501 and 6500/1 are not even similar, except
in that they use the same CPU core.

Eric
Received on Fri Nov 06 1998 - 18:34:47 GMT