[Info-vax] Whither VMS?

[Rich Alderson]

koehler at eisner.nospam.encompasserve.org (Bob Koehler) writes:

> In article <mdd63biv4sj.fsf at panix5.panix.com>, Rich Alderson
> <news at alderson.users.panix.com> writes:

>> (No, Tops-10 does not have a fork/process model of computation.)

>    Are you sure?  TOPS-20 certainly did.  I thought the TOPS-20
>    internals were based on the TOPS-10 internals.

I'm quite sure.  Tops-10 and TOPS-20 shared no code whatsoever.

I say this as someone who has used TOPS-20 since September 1977, and
Tops-10 since July 2003, and in the intervening time has made a living as
a TOPS-20 developer and adminstrator, and more recently the same for
Tops-10.

Tops-10 developed out of the standard DEC-style OS for the PDP-6 (April
1964), and feels very familiar to anyone who has ever used OS/8 or RT-11
(and even more so to anyone who used TSS/8, which was developed by some
36-bit engineers to give a Tops-10 feel to the PDP-8).

TOPS-20, on the other hand, is a descendant of the TENEX operating system
written at Bolt Beranek & Newman as an experiment in demand-paged virtual
memory operating systems c. 1970.  The original hardware for TENEX was a
PDP-10 (KA-10 CPU) with a BBN pager; it was ported to the KI-10 CPU (the
first machine labeled a DECsystem-10), and even ran in a master-slave
dual processor configuration.

TENEX became TOPS-20 when DEC bought the design for a PDP-10 clone from
the Stanford Artificial Intelligence Laboratory known as the SuperFoonly,
and turned it into the KL-10 processor of the DECSYSTEM-20.  The original
marketing plan was to replace all Tops-10 systems with TOPS-20 systems,
and we'd all march happily into the future.

Tops-10 customers had a great deal to say about that at DECUS--and the
Large Systems SIG was the most powerful at that time--so DEC retrofitted
Tops-10 to the new hardware.  When DEC introduced the DECSYSTEM-2020 (the
KS-10 CPU, a smaller departmental system), ADP did the Tops-10 retrofit
on contract to DEC.

-- 
Rich Alderson                  "You get what anybody gets. You get a lifetime."
news at alderson.users.panix.com                           --Death, of the Endless