30 Aug
2015
30 Aug
'15
9:47 a.m.
On Sun, 30 Aug 2015, Dave G4UGM wrote:
On Sat, 29 Aug 2015, Tothwolf wrote:
Something else I forgot to mention, is that on page 8 in that pdf file,
they mention initially using 60/40 tin-lead alloy solder for the enamel
wire to the core plane terminals. On page 9, they describe switching to
20/80 tin-lead so the solder would dissolve less copper from the enamel
wire.
If repair of the core memory in CHM's IBM 1620 is ever attempted, I think
either low-tin solder alloy with 1-2% added copper or possibly a more
modern indium-lead solder alloy would probably be the best choice for the
enamel wire to terminal connections since that would greatly reduce the
likelihood of any future wire breakage.
IBM had special machines to position and thread
them.
http://ibm-1401.info/IBMCoreArraysIEEEMagnetics1969.pdf
Thanks for posting that. Very interesting. Looking at it, the machines are
extremely complex, but I am sure they could be reproduced, albeit at a
probably prohibitive cost...
.. I have marked for later reading...