Redux of 6502==6800

From: Eric Smith <eric_at_brouhaha.com>
Date: Fri Nov 6 21:10:30 1998

"Richard A. Cini, Jr." <rcini_at_email.msn.com> wrote:
> I found some datasheets from Rockwell dated 1987 that day that *all* of the
> 65xx processor devices (i.e., the 6502-6507 abd 6512-6515)

Those weren't *all* of the 65xx processor devices (even in 1987). They were
just the "common" ones.

> were "bus compatible with M6800".

Bus compatible is vague. Yes, the parts listed above all used a bus very
similar to that of the 6800, and could be interfaced to the same peripherals.
But "compatible"? Not fully, since the 65xx parts didn't have a VMA signal.

> I'd like to have a consensus of:
> 1. the history of the 6502 processor

Since when is it ever possible to have a consensus about history? If
you asked Chuck Peddle you'd get one story; if you asked Motorola, I'm
sure you'd get another.

> 2. if there was a 6500 and 6501

There was definitely a 6501; I've got at least one.

AFAIK, there was not a 6500. There was a 6500/1, and other 6500/n and
6500/nn parts.

The 6501 and early 6502 parts (before September 1975 IIRC) did not have
the ROR instruction.

Cheers,
Eric
Life member of the 6502 Group, Golden, Colorado
Received on Fri Nov 06 1998 - 21:10:30 GMT