out-of-mainstream minis

[Paul Koning]

> On Jul 2, 2015, at 1:31 AM, tony duell <ard at p850ug1.demon.co.uk> wrote:
> 
> Not all minis came from the States :-)
> 
> One of my favourite non-mainstream families is the Philips P800 series. It's 
> a 16 bit machine with 16 registers (0 is the program counter and 15
> is the stack pointer, rest are mostly general purpose) and separate
> I/O instructions (not memory-mapped I/O).

Another Philips machine, probably still more obscure, is the PR8000.  I’ve been looking for documentation about it, with no luck whatsoever.  I wrote up a partial description, from memory and from looking at some old listings.  It’s a 24 bit machine, with 8 sets of 8 registers (memory mapped like the PDP-10).  For each interrupt level there’s a set of registers, so at interrupt time no register saving is needed.  Neat.

	paul