Testing the HP-35 calculator chips at Mostek

[brouhaha]

HP had two competing sources of PMOS chips for the calculators they developed prior to the HP-27 and HP-30 series, Mostek and AMI. Both vendors were given the engineering requirements and did their own circuit design and layout. Generally the corresponding chips from the two vendors were interchangeable, but there were occasional exceptions.

Last fall, Fred Beckhusen wrote an article about his experiences at Mostek doing chip testing:

https://mitsi.com/case-studies/the-hp-35...rd-tester/