Comment by znpy

I had a similar experience. Our professor in high school would have us program a z80 system entirely by hand: flow chart, assembly code, computing jump offsets by hand, writing the hex code by hand (looking up op-codes from the z80 data sheet) and the loading the opcodes one byte at the time on a hex keypads.

It took three hours and your of us to code an integer division start to finish (we were like 17 though).

The amount of understanding it gave has been unrivalled so far.