All right, here's some things that I tend to remember FWIW (and my brain
cells are starting to fade a bit): (and it is NOT a tree)

(1) I was definitely using a PDP-1 (18 bit) from 1961 through 1968.
There was no operating system as such. I wrote a couple of them, one of
which used DDT (which was a symbolic debugger, which I got to display on
that nice DEC monitor tube). Would SpaceWar count as an OS? If you want
a copy of the Java/Perl emulator of SpaceWar which runs on M$oft, let me
know, and I'll send you a copy... (it's a link to MIT)

(2) PDP-5's (12 bit?) didn't have much of an OS either.

The above 2 were paper-tape based, although we did eventually interface
an IBM tape drive to the PDP-1 at Princeton. That was used to "spool"
listings to a 1401?, where I forced Autocoder to print the contents of
the tape :-)
My program (including the time slice interrupt driven code) ran over 180
pages of macro listing, which is why I had an interest in something
faster than a flexowriter. Never underestimate the bandwidth of a mag
tape on a bicycle...

(3) PDP-6 (36 bit). That had a nice, time-sharing operating system.
There was even a small disk, although it was primarily dectape driven.
I'm sure one of you will chime in with the name of the earliest OS on
the PDP-6; it eventually morphed into TOPS-10, and then TOPS-20, running
on PDP-10, then 20's. There was also something called TENX, but I can't
remember what that was anymore.

(4) PDP-7 (18 bit). I remember that it had some kind of "Disk Operating
System". Used to develop the earliest versions of UNIX.

(5) PDP-8 (12 bit?). I don't remember much of anything about that, but
it morphed into a word processor :-)

(6) PDP-11 (16 bit). This was an awful machine. IIRC, it was the first
of the DEC machines which used 8-bit, instead of 6-bit, characters; and
the memory size was 16 bits, instead of the much heftier 18 bits in the
PDP 1-4-7 family. However, despite requiring the programmer to learn
hexadecimal notation instead of the much easier octal, it did catch on,
and spawned a whole slew of operating systems: DOS, RT, RSTS, RSX-11D,
RSX11M, RSX11M-Plus, among others. Mumps, too.

How would you describe TKB? As a disk exerciser? The first manufacturer
supplied computer virus?

(7) VAX11/780 (IIRC, that was the name of the first machine, but I could
be remembering wrong). The OS definitely evolved from RSX11; the
utilities, as Dave Schmidt reminded us recently (on the VMS-SIG mailing
list) all ran in PDP-11 emulation mode, and were the actual RSX-11M
utilities, such as PIP and all of the RMS utilities (which, IIRC, did
not go away until version 3, when we finally got a native-mode convert).
(and case sensitive logical names, but no way to translate them until
3.2)

...

Carl

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] 
Sent: Thursday, April 03, 2003 11:16 AM
To: Brad Hughes
Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: Re: vmsperl Digest 2 Apr 2003 21:19:24 -0000 Issue 685



Brad Hughes wrote:

!Does anyone have an OS genealogy tree...

The one at:

  http://www.levenez.com/unix/

is strictly Unix variants.  There is no mention
of VMS, although a Wollangong product
appears branched off of System 6 in 1977 or
so, and Ultrix I appears in about 1981.

Peter Prymmer


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