For those interested in Seymour Cray's background
There's a veteran's group of old staff of companies for which he was a member
One of Cray's lesser known achievements was using a computer (back then hugely expensive) to help manufacture more of them reliably, developing some of the first CAE software to take care of the mental "grunt work" of logic equation checking, front panel layouts etc. Obvious now, but very bold for the early 1950's.
One of the history files points out this was possible because a secret government customer was willing to support the effort. This was long before CDC existed.