I got hold of an old Sinclair ZX81 in apparently good and working condition!
ZX81 was the first personal computer I owned. I was 13 years old. At that time, I copied its 8K ROM, byte by byte, into a notebook, and hand-disassembled it (a consequence of which I still suffer from: I still remember some Z80 opcodes), but I never opened it. Finally, now I can do what I missed 🙂
This post shows how it generates TV images and how its Z80 CPU boots. I instrumented it and captured scope and logic analyzer images as it was powering on.
What a beauty!
