On 27 Jan 2012 at 0:08, Rob Doyle wrote:
I work in Aerospace. We are still shipping lots
of products that use
the Intel 188 and 186 of different variants... ditto 386DX, 386EX,
It was never intended to do DOS. It was an embedded controller. Most
of the peripherals were not PC compliant and they certainly weren't
mapped at the right IO addresses.
I'll take issue with that, Rob. Bill Davidow was on our board of
directors. When the software and hardware people ptiched the Moto
68K as a processor for the new machine, Davidow got mad (the 80286
was still not ready for prime time) and said it would be a cold day
in hell if any product he had any say in wouldn't use an Intel
processor. At the time, DOS (MS, SC, or PC) wasn't an issue.
We were pointed at the 80186, along with the yet-nascent 80286
(they'd gotten real-mode sort of working, but PM wasn't there yet).
The 80186 early steppings we were given were pretty buggy--one bug
that still sticks in my mind is one where the SI and DI registers
could be destroyed if an interrupt hit during a DMA operation. We
went up to Bellvue and talked to Microsoft about Xenix on 2 CPU
machines and came away with a listing of the I/O mechanism used on
the TRS-80 model 16 (uses the Z80 for I/O, but otherwise executes on
the 68K). At no time did the subject of the PC ever come up,
although we did port an early copy of MS-DOS (1.something) to the
80186. The subject of IBM PC compatibility never came up.
Altos and Televideo were also involved in using the early 80186
The problem was that Intel didn't really have anything ready to
supplant the 8086, which was already showing its age, particularly in
comparison to the 68K and the not-yet-ready-for-primetime NSC CPU.
The 432 project had fizzled badly and the 186 and 286 were the only
thing Intel had close to being ready at the time. The support
peripherals for the 8086 were really old technology as well, mostly
created to work with the 8085.
It's interesting that the 80C186 EC contains several IBM-PC compliant
components, such as cascaded 8259 PICs. So DOS was somewhere in
I worked with the 386EX for several years and always had the impression
I could run DOS on it if only I was willing to create a BIOS for it. We
were using it in an embedded way so I never seriously looked into it
though, so ICBW.
In God We Trust!!!