On Fri, Aug 28, 2015 at 5:08 PM, Lyle Bickley <lbick...@bickleywest.com> wrote: > On Thu, 27 Aug 2015 14:28:30 -0500 > Ben Sinclair <b...@bensinclair.com> wrote: > >> The CHM has a bit of information, and links to three other 1620's that >> they know about: >> http://www.computerhistory.org/projects/ibm_1620/ibm1620/ >> >> From what I've been reading, there may be only one operational 1620 >> right now, but the CHM is also trying to restore one. > > The IBM 1620 at the CHM is a running computer. There were two teams that > worked on the 1620 at the CHM. The first Team got it running. Unfortunately, > IBM used the wrong kind of solder on > the core memory and so the wires of > the core memory literally "dissolved".
That sounds suspiciously like a problem Henk Stegeman told me he had encountered with the core memory on a System/3; the problem there had been a reaction between the core memory solder (or was it the actual wires used to string the cores?) and the foam used to make a seal for the air cooling through the core... either way, vital bits of the core stack got dissolved by the foam over 40 years... Mike
