Post #2474895

@nedbat@hachyderm.io "Oscilloscope? Really?" Yes really. Once I had trouble with the first dozen or so bootstrap instructions on a system - it didn't get to the point where all the built-in debugging features could start working. So we hooked up an oscillator to continually poke the CPU's RESET line, and read off each address and data line one at a time with a scope, to see what the first few instructions were doing. Yes this was slightly tedious, but it got us to diagnose and fix the bug (I don't recall whether it was hardware or software - this was prototype hardware as well of course).