Inside a transistorized shift register box, built in 1965 for Apollo testing

80 · Ken Shirriff · June 16, 2021, 5:27 p.m.
.hilite {cursor:zoom-in} a:link img.hilite, a:visited img.hilite { color: #fff;} One of the under-appreciated aspects of the Apollo launches to the Moon is how much testing was required. I recently came across an item that was part of this testing: the Computer Buffer Unit. It is essentially a 16-bit shift register that interfaced test equipment to the Apollo Guidance Computer. While a shift register is a trivial circuit nowadays, back then it took a box full of transistors that weighed ab...