On 08/30/2015 11:15 AM, Paul Koning wrote:
So there'd be what, 120,000 cores to thread? That might be a bit
daunting from a human-hour standpoint. I'll wager that 120K cores
wasn't even a day's output for outfits like Fabritek.
Those cores weren't threaded one by one. You'd start by setting the
cores into a holding jig, which positions them correctly. Then you
thread wire from edge to edge. The article mentions a needle with
the wire welded to its end; that makes sense because the copper wire
is unlikely to be stiff enough. So the number of individual
threading operations is 3-4x the square root of the core plane size.
For example, on a 4k core plane, it would be 200 steps, give or take.
(A bit more on a CDC 6000 series core plane with its peculiar 5 wire
architecture.)
I've seen the archival photos. Still, the possibility of missing or
damaging a single core was always there. I wonder what the rejection
rate was.
I have heard of machine-fabricated core as well, but I thought that it
only applied to larger, slower bulk core store. One can certainly
understand why plated-wire or thin-film technologies were attractive.
Sigh. Another lost manual art. I can remember during the 70s that the
hot thing was to learn IC layout--the wives of a number of co-workers
were going to night courses for that.
--Chuck
