IBM did develop a machine to thread the wires through cores. The cores
where held in place in a tray by vacuum and wires threaded through by
hollow needles to quote the book IBM's Early Computers, "When introduced
in 1959, this core threading machine reduced the time to thread X and Y
wires in a 64x64 plane from 25 hours to 12 minutes" From that quote I
am guessing that the sense and inhibit lines where still wired by hand.
Paul.
On 2023-04-25 10:38 a.m., Paul Koning via cctalk wrote:
On Apr 25, 2023, at 9:25 AM, KenUnix via cctalk <cctalk@classiccmp.org> wrote:
Rod,
Never heard the singing. Switch room's were too noisy.
It always amazed me that those core planes were hand wired. I guess by
little people. Or, big people with little hands.
People (often women I think) with steady hands. I think the setup used a work
surface with notches in it corresponding to the positions of each core. They
would pour a cup full of cores onto that and use gentle shaking and vibrating
to get all those notches filled, then pour off the excess. Next, threading the
cores much like you thread a needle -- except that the wire is stiffer than
thread and thus easier to make it go straight through.
One wonders if this could have been done by machine. Probably yes, but given
the volumes involved I suppose the capital investment wasn't justified.
The more amazing kind of hand-wired core is core ROM, where the wires weave in
and out of various cores according to the required bit pattern. Getting that
right seems like a far more complicated craft.
paul
