Depends, we only had the local library, some books we could acquire and computer magazines listings as source of knowledge.
I certainly did not felt that great manually translating Z80 opcodes into DATA entries, to be loaded via RANDOMISE USR instructions.
Got a bit better with hexdump editors, but good luck tracking down checksum errors.
Finally, debugging meant manually simulating the execution on paper, with arrows and boxes, to try to get a feeling of what could be root cause for the error.
I certainly did not felt that great manually translating Z80 opcodes into DATA entries, to be loaded via RANDOMISE USR instructions.
Got a bit better with hexdump editors, but good luck tracking down checksum errors.
Finally, debugging meant manually simulating the execution on paper, with arrows and boxes, to try to get a feeling of what could be root cause for the error.
Yeah, what a time.