On Wed, Feb 3, 2021 at 5:14 AM Ed Bradford <egbegb2(a)gmail.com> wrote:
Hay, Arnold,
MC 68K was created in 1980 or thereabouts. We talked about 10's of
Megahertz, I think, in those times.
The original X series part was originally unnumbered but a sticker was
later set for the lids that said X68000 (I had one on my desk - which was
used for the Tektronix Magnolia prototype).[1] The X series ran at 8 Mhz,
but the original released (distributed - MC68000) part was binned at 8 and
10 as were the later versions with the updated paging microcode called the
MC68010 a year later. When the 68020 was released Moto got the speeds up
to 16Mhz and later 20. By the '040 I think they were running at 50MHz
[1] I think I still have the draft list of issues in my files. There was a
halt and catch fire style error you had to be careful about (I've forgotten
the details - but if you executed it in supervisor mode, the ucode turned
on the address drivers in such a manner that they stopped working after
that and the chip was ruined). I only did that once ;-) when we were
debugging Magix (the OS for Magnolia)