Re: Fwd: Re: Microsoft and Xenix.

From: Patrick O'Callaghan (
Date: Tue Jun 26 2001 - 07:57:28 EST

Ah, fame at last :-)

I'm not on the linux-kernel list but a friend forwarded me this message:

> Subject: Re: Microsoft and Xenix.
> Date: Mon, 25 Jun 2001 18:11:01 +0100 (BST)
> From: <>

> I first used Unix on a PDP11/44 whilst studying for my Computer
> Engineering degree at Heriot-Watt University in Edinburgh. I think
> they and Queen Margaret
> College, London were the first folk running Unix version 6 outside
> Bell Labs.

It was in fact a PDP-11/45. Unix 5th Edition was first installed by Peter De
Souza around January 1975 (if anyone knows Peter's whereabouts please mail
me; I know he emigrated to the US and I lost track of him). Anyway, the 11/45
had only 48kb of (core) memory, which was enough to boot the system and run
the Shell but almost nothing else. We had to connect the machine to a
neighbouring 11/20 with Unibus cable and a special bus switch box built
in-house in order to do anything. This quickly improved when we purchased a
256kb semiconductor memory board from Plessey (the DEC guy couldn't believe
all that memory would fit on only one 19-inch board :-). It cost 3000 quid.
We had 2 RK05 removable disks (2.5 Mb each!) and a paper tape reader. Note
that we had no tape drive, and Unix came on a reel of tape, so we had to
trudge around various places in the Edinburgh area doing media conversions on
non-Unix machines. Oh how we laughed. We later bought an SMC 80Mb removable
washing-machine style disk for I think about 15000 pounds (for which we had
to fight off the Control Engineering guys who wanted to buy a floating-point
unit -- yes, the fp was emulated!).

This system supported around 10 ASCII terminals via a DZ-11 serial-line
multiplexor. Memory was so tight we couldn't run VI, but I wrote my PhD
thesis on it (in NROFF) using George Coulouris' EM editor from Queen Mary
College (not Queen Margaret). They were the first to run Unix in the UK along
with us. I've never known who was really the first because of course there
was no Internet, not even UUCP mail. We may even have been the first in
Europe for all I know, though I think Andy Tanenbaum was fairly close behind.

Anyway, I'll not rabbit on. Those were the days when men were men, real
programmers wrote assembler, and we didn't need no steenking GUIs (mumbles
into beer).

> If anyone knows where Patrick O'Callaghan is now (ask
> him).

I'm at Simón Bolívar University in Caracas, Venezuela. My home page is



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