17 Jun
2026
17 Jun
'26
8:07 p.m.
On Jun 17, 2026, at 2:29 PM, David Wade via cctalk <cctalk(a)classiccmp.org> wrote:
On 17/06/2026 19:48, Van Snyder via cctalk wrote:
Multics has been running on modern hardware for years via emulation. It works just fine
on a Raspberry Pi, and it amuses me to have it running on a system the size of a deck of
cards, when I think about the DPS-8’s I used to work on (running GCOS-8).
Sadly, as far as I know, no one has gotten GCOS running, as I don’t know of anyone with
the software.
https://gitlab.com/dps8m/dps8m
https://dps8m.gitlab.io/dps8m/
https://multics-wiki.swenson.org/
Zane
A bit tangential, but… speaking of Assembler, I
remember hearing
decades ago that Multics was 85% PL/1 and 15% assembler. Has anybody
gotten Multics running on modern hardware, such as Intel? — probably a
better platform for it than the GE 645 or Honeywell 6180.
Multics assumes multiple security levels in Hardware and single level storage so I think
its simpler to write a hardware emulator for the Honeywell/Bull hardware that shoehorn it
onto x86.
I think even creating the hardware emulator, which does exist, but which I haven't
used, might be fun as the machines used to run Multics have 36-bit words which can be
treated as a word, 6 by 6-bit characters or 4 x 9-bit characters. I believe Multics
generally uses the 4 x 9-bit byte format for character data, except when running GCOS 3/8
EMULATION so I am not sure how you handle this on Intel.
Dave
G4UGM
Former Systems Programmer on Honeywell Level66/DP300 whos hardware formed the basis for
the Multics machines.