Youtube Video 1970s HP 9825 Repair
One of my favourite channels, CuriousMarc, you may recall his channel and team repaired to working order, the Apollo AGC and flew it in a simulation. Here Marc tackles in his usual detailed manner, the repair of his beloved HP9825
Parts 7 & 8
In Part 9 of this fascinating series (OK to some), Marc speaks to one of the original HP designers.