23 May
2005
23 May
'05
1:21 p.m.
Tore wrote about threading core memory:
The machines were
far more expensive than having a human do it - IIRC they had ways of
doing it automatically since the 709 but they were too expensive.
Actually they used automation for the X and Y wires starting fairly
early on, because that was cheaper than human labor. The cores were
vibrated into positions on a metal plate with indentations, then long
needles (like hypodermics) were propelled through a row or column of
cores. The wire that was threaded through the needle was soldered to
the frame, the needle withdrawn, and the wire soldered at the other
end.
It's the zig-zag sense/inhibit wire that was done manually for many
years, because it was much harder to automate.
it's in "IBM's Early Computers",
where there's a whole chapter on it.
A great book; I'd go so far as to call it "required reading" for
anyone interested in computer history. But for more details on core
memory, see "Memories that Shaped an Industry: Decisions Leading to
IBM System/360" by Emerson Pugh, one of the coauthors of the former
book.
Eric