21 Oct
2010
21 Oct
'10
6:29 a.m.
From: William Donzelli <wdonzelli at gmail.com>
I have a mental picture of a mercury delay being rocked back and forth by the motion of a
battleship :-)
Certainly mechanical analogue computers were common in fire control, and must have got
replaced by something more modern, but I would restrict the list to stored program
machines. Nickel delay lines were likely used and drums used directly for executing code
would of course work on a ship too. Williams tubes maybe, and the earliest core memory
machine would have been military too.
I am not interested in machines which have not
been powered up for more than a year, even if they were operational when stored, the
likelihood of them working when turned on again is low. Expansion and contraction, static
electricity, chemical reactions especially in old electrolytic capacitors take their toll.
Computers were built to be used, one which cannot be operated is no more interest to me
than the hull of an old ship.
Interesting you mention hulls of old ships and oldest operating
computers. It is likely that any list of "oldest operating computers"
would probably be dominated by special purpose digital* computers
(fire control, navigation, crypto, etc.) on ex-US and Soviet warships
serving in third world navies. Even in the backwaters of the US Navy
there are still some ancient machines still going. Military computing tends to be 800 pound gorilla in
the room that
historians tend to dismiss.
Maybe because they are excluded by secrecy, as happened with the UK's WW2 German code
breaking machines until the story got out and Bletchley Park was saved.
In my first job I came across several military computers, but they were for use in
aircraft and so much less heavy. I worked on the Mk2 Nimrod, based on the Comet, and
I've heard tell that in its first incarnation it was bright aluminium because if they
painted it the weight of the paint would have stopped it from becoming airborne.
* The submarines of Taiwan still use the Mk IV Torpedo
Data Computers
(mechanical analog), installed when the boats were still US during
World War 2.
Interesting, but not a stored program computer.