[comp.misc] Bored Core

hughes@endor.UUCP (06/03/87)

In article <8252@bu-cs.BU.EDU> bzs@bu-cs.BU.EDU (Barry Shein) writes:
> ...
>
>On an opposite note I remember stories of programs which would be run
>in the background to exercise core memories, that long unused areas
>tended to go bad.
>
	If you don't use magnetizable material for some period of time,
it loses its ability to be magnetized ?? Or, if you don't use a core
driver (semiconductor or vacuum tube) for some time, the driver will
go bad (faster than a used driver) ?? I don't believe it. I would believe
that a relay based memory (boy, are we talking ancient) would go bad
after long disuse because of contact oxidation.
	You don't believe computers once used relays ? In the lobby of
Aiken, one whole wall is taken up by PART of a relay-based computer.
Another wall has display cases that contain what was the latest computer
technology from IBM - various models of multi-pole double throw relays.
(Actually, I haven't ever seen the inside of the new RTs ... :-)).

aad+@andrew.cmu.edu (Anthony A. Datri) (06/03/87)

I've seen the inside of rt's.  CMU has the great misfortune of having
shitloads of them.  Don't get me wrong -- we didn't buy them.  The people who
decided these things aren't *that* brain damaged.  They belong to IBM.  The
RT is comprised of approximately 3.4 million micro-relays.  How IBM managed
to make a relay 20 microns across is beyond me...


anthony a datri
carnegie mellon university (a subsidary of ibm)