On Thu, Jun 30, 2016 at 11:49 AM, Larry McVoy <lm(a)mcvoy.com> wrote:
On Thu, Jun 30, 2016 at 11:32:08AM -0400, Dan Cross
wrote:
MC68000 vs Intel 8088 seems like a no-brainer:
the 68k is the superior
chip. From a business perspective, I guess it was a very different
matter,
Yup - you take what you can get. And if Moto is not doing to sell it you
when you are designing a new system.
but
that's not my area and the ship has long sailed over the horizon.
Still, it's fun to speculate and I can't help but think that a 68k-based
IBM PC would have been a nicer machine.
+1
+1 And I suspect so many fewer problems would have ensued. At least
linear addressing would have been de rigueur from day 1;-)
Something I never understood about the IBM PC:
even the 8088 machine was
fairly beefy compared to e.g. a PDP-11/20. The 6th Edition Unix kernel
was
objectively pretty small and understandable;
mini-Unix showed that that
sort of software could be used on a machine without an MMU. I've never
understood why IBM didn't just write a real OS in a high-level language
instead of saddling the world with MS-DOS. Perhaps it's naive of me, but
even if they didn't use Unix directly, it was an existence proof that
such
a thing was possible. I suppose, again, it was
less a technical issue and
more a business issue, or perhaps I'm underestimating the amount of work
or
missing some of the technical complexities.
I wonder if they just didn't know.
Possible -- ignorance of that team would have been high, certainly at the
managerial layers. You might ask Guy Sotomayer who showed up in Boca soon
after the release if not before it. Guy certainly knew UNIX (he was one
of my lab partners at CMU) and I'm sure a number of his peers did also.
Unix was Bell Labs and Universities for
the most part.
Mumble, IBM was selling to universities and has a strong on-site presence
at MIT (that's were VM came from). Boca was doing stuff with 8085s and
this was "entry systems" so I think the field of view was a lot more
shallow. But parts of IBM knew about UNIX and TOPS-10. One of Guy and
my other lab partners was Chris Pathe', who graduated from CMU to work for
IBM, but programming DEC systems for them. They hired him because he knew
TOPS and UNIX, *etc.*
Was the timing such that they may not have been aware
of
Unix? Or maybe they knew about Unix but thought it was for the vax?
Stuff I have read said that IBM wanted to compete originally with S-100
type systems with this new system. Hence the famous desire for CP/M.
They always were primarily buying the SW from firms that had built SW for
microprocessors. And, if I understand the history pieces that have been
published, the project was financed by large systems, that wanted to system
to run VisiCalc, which was a hit in financial circles. But large systems
team were not doing much the SW themselves for these boxes. It >>seems<<
like IBM was thinking about SW in terms of very large machines so even
PDP-11's were small in those days. That said their marketing folks for the
PC, put the focus on 16 bits was because they wanted to be "better" than
the 8-bit 8080/8085/Z80 that was the S-100 standard or the 6502 in the
Apple II. Hence, Moto pushing an 8-bit chip was rejected.
Clem