17 Nov
2001
17 Nov
'01
8:35 a.m.
Re:
> The 16-bit HP 3000 was never multi-CPU. The HP
3000 Series III, introduced
...
Somebody had ideas about it being a dual-CPU
shared-memory system
early on. Looking at the HP3000 Computer System Reference Manual from
September 1973, I see that locations %10-%13 were reserved for the
second processor's current PCB pointer, QI, ZI, and interrupt count.
The Series II added two instructions: LOCK and UNLK, which were used
Thanks...I'd forgotten those were Series II and not Series III.
What I don't know is whether MPE ever had dual-CPU
support. If it
didn't, I wonder how they worked out that having an in-memory
semaphore would be a good idea.
My recollection, and it is a hazy one, is that in the mid 1980s I heard a rumor
inside HP that someone had actually tried a dual CPU Series II in the lab in
the last 1970s, but the project was dropped for some reason. I'll ask some
of the older 3000 people about it.
Stan Sieler sieler(a)allegro.com
www.allegro.com/sieler/wanted/index.html www.allegro.com/sieler