History of Computing exam question

From: Geoff Roberts <geoffrob_at_stmarks.pp.catholic.edu.au>
Date: Sat Dec 1 19:36:36 2001

----- Original Message -----
From: <CLeyson_at_aol.com>
To: <classiccmp_at_classiccmp.org>
Sent: Sunday, December 02, 2001 10:43 AM
Subject: Re: History of Computing exam question



> 4) 1940 ?
> Enigma - Electromechanical state machine. Colossus wouldn't have
> been built without it.

Hmmm, possibly true, though not for the reason you state. The success
against Enigma using 'cracking' machines led to the idea of building
Colussus to crack the "Fish" machines.

> 5) 1943
> Colossus - Vacuum tube code craker. Not a general purpose machine,
> built solely to solve Enigma ciphers. Hard wired coding and paper tape.
> 1500 valves.

Actually it was built to crack the Geheimschrieber ("Secret Writer")
ciphers, several versions of which
existed, and were referred to by the Brits as the "Fish" machines. I think
one specific machine was known to the Brits as "Tunny" and another as
"Salmon". They were used by The German High Command to distribute orders
from the Government (read Hitler) to the various arms and embassies and were
a radically different type of ciphering process to the simpler Enigma
system. IIRC it used an additive numerical encryption of some kind. The
Enigma code was dealt with by the Bombes, an Alan Turing altered variant of
the original Bombes used by the Poles to crack the early Enigmas in the late
1930's, prior to WW2. Like the Enigmas they were used against, the Bombes
were electromechanical. Bletchley Park were well into much Enigma traffic,
(except for the Reichsmarine, who were much more careful in their useage
habits) long before 1943.

> 13) 1968/9
> The Apollo guidance computer - Helped get man to the moon.

Are we talking about the ones on the ground or the ones in the spacecraft?
If the spacecraft, was the one in the LEM the same machine? Anyone got any
info on it? Any examples survive?

Cheers

Geoff Roberts
Computer Systems Manager
Saint Mark's College
Port Pirie,
South Australia
geoffrob_at_stmarks.pp.catholic.edu.au
Received on Sat Dec 01 2001 - 19:36:36 GMT