BBC’s 13 Minutes to the Moon

This great podcast goes into considerable detail about the development of the hardware and software for the onboard computers used in the Apollo program.

The development process was a bit different in the mainframe days, when you didn’t get to run things from your terminal and get immediate feedback. One interesting bit is that the keypunch operators acted as a sort of syntax checker. You don’t need to really understand code to spot an unclosed parenthesis.