[henrikschroder]

One of the most enlightening courses I took in university back in the day was digital electronics. Not because I ever wanted to muck about with it, but because we actually got to build our own super-simple physical 8-bit CPU. We had registers and an ALU and RAM and eight output leds, and we got to write the microcode for the fetch-execute cycle. Clock? There was a physical switch you would toggle on and off to make it step through the cycles to slowly execute the program we wrote in our own machine code. Realizing that instructions are just a bit-pattern saying which unit should write to the bus and which unit should read from the bus was quite eye-opening.

[SoftTalker]

Old minicomputers had toggle switches on the front panel where you could set the program counter, enter machine code instructions, and other things, as well as step the clock.

https://thumbs.worthpoint.com/zoom/images2/1/0619/05/vintage...

[stonethrowaway]

Image no longer works. Reupload?

[SoftTalker]

It's not my site. It's the front panel of a Texas Instruments model 980. It's from this page.

https://www.worthpoint.com/worthopedia/vintage-ti-980-ttl-ba...