If anyone is interested in what happens with an older CPU, I've written up how the IBM 1401 from 1959 starts up: https://www.righto.com/2021/02/an-ibm-1401-main

If anyone is interested in what happens with an older CPU, I've written up how the IBM 1401 from 1959 starts up: https://www.righto.com/2021/02/an-ibm-1401-mainframe-computer-at.html https://www.righto.com/2021/02/an-ibm-1401-mainframe-compute... Among other things, since it uses magnetic core memory, you can run the program that was loaded when you shut it off.