If you're fond of trying out multiple operating systems without the hassle, you're probably using virtualization regularly.

In this case, the memory address of the new next instruction to be fetched is copied into the program counter. The process then restarts at step one.

Despite what the cool kids are doing over on Hackaday Projects, the vast majority of vintage computers used some form of programmable logic for memory control, address decoding, and all that other … ...