In August, 2001, I had a get-together with Bruce Mitchell and Ralph
Stammerjohn at
Ralph's summer place in Wisconsin (near the Dells).  Bruce videotaped while
I did
a mind-dump.  I traced the roots of RSX back to 1959 and showed when and why
it evolved as it did.  I have a copy of the three raw videotapes amd Bruce
was going to
get them edited (they are a bit amateurish, to say the least.)  However,
things keep
coming up....

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.

My wife and I have a small website and on it you will find some old
documents.
http://www.demillar.com/RSX/

First, an outline I prepared before the aforementioned videotape was made.
It's really
just notes by me but may contain things of interest.

Next is a very early informal writeup very early in the effort, written at
the urging of Bob McInnes.
You will see RSX taking shape.

Third is the oldest:  it is a list of macros for "DEX-15" which was the
first name for RSX-15.  This
list is extremely early and changed quite a bit, but you can see RSX begin
to form.

Then there is a letter of reference writen for me by Bernie LaCroute.

The first released version of RSX-15 was provided with source.  On the title
page is the
statement that RSX-15 was programmed by  Sam Reese, Dan Brevik, Hank Krejci
and
Bernard LaCroute.

 You might also like to visit Bruce's site for some anecdotes.
http://www.miim.com/
Click on "An RSX FAQ"   When you get there look at "General", "Software
Generalities" and
"The Executive"

Regards,

Dan Brevik