On Thu, 2003-11-27 at 19:09, Johnny Billquist wrote:
On Fri, 28 Nov 2003, Warren Toomey wrote:
Hi all,
I stumbled across this reference to a 1975 Masters thesis:
de Brito Meyer. W., and Hawley, J.A.. III. Munix. a multiprocessor version
of UNIX. Master's thesis, Naval Postgraduate School, Monterey, Calif.. 1975.
Description of dual processor Unix.
Can anybody tell me what PDP11 platforms around 1975 had multi-CPU
capability? Also, if anybody has further information about Munix,
please let me know!
Thanks in advance for any help. I've trawled thru the Unix Archive
with no results.
I remember that CMU built a MP system out of 11/40 systems...
Search for C.mmp (if my memory is correct).
C.MMP was 12 11/40's and 4 11/20's. Each processor had 4KW of local
memory + the 4KW I/O page. The rest of the memory (1.2MW) was
accessible through a "cross-point" switch (ie it wasn't a common memory
bus...think of it as 16 port memory -- there was no memory contention
unless 2 processors wanted to access the same page (4KW) of memory).
In addition to the cross-point switch there was special IPC
(Inter-Processor Communication) hardware to allow the processors to
interrupt and communicate with each other.
The O/S that was run was Hydra a very radical capability based system
(ie everything was represented as a capability -- files, programs, I/O,
etc). If you didn't have a capability for something you didn't even
know it existed. It was very cool!
Somewhere I still have my "Hydra Songbook" which contains a bunch of
details + kernel calls about Hydra.
There was a predecessor (prototype) that supported either 2 or 4
11/40s. I remember seeing it in the same machine room as C. but don't
remember what it being used for at the time as it was "discarded" from
the C. project.
I think they built some special hardware for this. And since these
machines don't have a cache, it makes life easier...
--
TTFN - Guy