Re: the 286, Byte ordering

MitchAlsup1 wrote:

On Sun, 5 Jan 2025 20:01:25 +0000, John Levine wrote:
 

According to Anton Ertl <anton@mips.complang.tuwien.ac.at>:

Anyway, while Zilog may have taken their sales, I very much believe
that Intel was aware of the general-purpose computing market, and the
iAPX432 clearly showed that they wanted to be dominant there.  It's an
irony of history that the 8086/8088 actually went where the action
was.

>
I have heard that the IBM PC was originally designed with a Z80, and
fairly late
in the process someone decided (not unreasonably) that it wouldn't be
different
enough from all the other Z80 boxes to be an interesting product. They
wanted a
16 bit processor but for time and money reasons they stayed with the 8
bit bus
they already had. The options were 68008 and 8088. Moto was only
shipping
samples of the 68008 while Intel could provide 8088 in quantity, so they
went
with the 8088.
>
If Moto had been a little farther along, the history of the PC industry
could have been quite different.

 If Moto had done 68008 first, it may very well have turned out
differently.

But neither of these were possible (i.e. available) when IBM picked their CPU.
I do believe that IBM did seriously consider the risk of making the PC too good, so that it would compete directly with their low-end systems (8100?).
At least, that's what I assumed when the PC-AT only ran at 6MHz on a CPU which was designed for 8 MHz. I fondly remember a bunch of overclocking hacks on various 286 machines, most of them ran at 9 MHz, and I don't think I saw any that didn't handle 8 MHz.
Terje
--
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"