Oldest machine

[Chuck Guzis]

On 12/19/2005 at 12:46 PM William Donzelli wrote:

>In the good old days, core planes were indeed repaired by hand, 
>often during initial construction. Sometimes you can see the tiny splices.

At CDC, we used to joke about the "Tiajuana Core House"--at one time, bulk
core (ECS) was being assembled there, IIRC.

I remember an IBM CE poking around in a 7090 with a broomstick with a small
magnet attached to the end to retrieve fractured bits of core after he'd
given the unit a couple of good whacks to free them.

Core can be very fragile stuff, particularly when it's being heated by
repeated access.  I recall that the CDC 7600 had some sort of duty-cycle
integrator installed on PP memory because repeated hits on the same
location would cause overheating and parity errors.

Cheers,
Chuck