[ih] Where's Multics now, was Internet-history Digest

[Jim Carpenter]

On Sun, Aug 17, 2025 at 4:11 PM Clem Cole via Internet-history
<internet-history at elists.isoc.org> wrote:
> Ouch... VMS's parent was RSX, and that's parent was a real-time system Dave
> wrote for the PDP-10 when he was at Dupont before DEC hired him.   To
> my knowledge, Dave had not read Organick's book when he did those systems
> (I'm not sure he has even today).   He was purely a real-time guy/process
> control guy - not a multi-user/mult-tasking.

According to Johnny Billquist, Dave Cutler did a
"redesign/reimplementation" of RSX-11D, which became RSX-11M. That
then became the starting point for VMS. RSX started at DEC with Dan
Brevik on the PDP-15 as DEX-15/RSX-15, then was brought over to the
PDP-11.

This is part of a post from Dan Brevik on comp.os.vms dated 7/27/2003
( http://groups.google.com/groups?selm=g11Va.162679%24ye4.109589%40sccrnsc01&output=gplain
):
> RSX did not come from a DEC operating system, as you observed. It's intellectual
> precedants were a realtime executive writen by John Neblett (now retired in Ashville, NC)
> for the RW-300 process control computer. Thence to "The Synchronous Executive" by
> me about 1963 for the TRW-330 process control computer. Then I headed the project
> to write "Ops Control" for the BR-340 in 1964 (Dupont loved it). Bunker-Ramo left the
> process control business and I joined Honeywell where I managed the project for OLERT
> on the DDP-516 (John Haynie and Walt Duncan, chief architechs and developers). I joined
> DEC in 1969 in marketing (all marketeers were engineers at that time) and hired Sam Reese
> part time to help me write a real time executive for the PDP-15. (Paid him $15,000). I had
> known Sam at Honeywell where he dashed off a small RT exec called Samtran. This gave me the
> time to just sit back and think. The basic specifications and architecture came primarily out of me based
> on experience.

The Ramo-Wooldridge RW-300 was announced in 1957 and available in 1959.

Visit https://web.archive.org/web/20050404121912/http://www.demillar.com:80/RSX/
and read his outline/notes for more tidbits. And FYI, he does write
"MULTICS was not an influence."

Jim