Electronics and low level

Boolean equations derived from truth tables, simplified with Karnaugh maps and mapped onto AND, OR and NOT gates and T flip-flops. No behavioural shortcuts, which is slower to write and much easier to get wrong, and that is exactly the point of doing it that way.

Projects in this area

68k Simulator

The simulator midway through the recursive factorial tutorial, showing the source code, the register panel, a memory dump and the stack.

A Motorola 68000 emulator that runs in the browser. You write 68k assembly in the page itself, assemble it right there and step through it while watching the registers, memory and stack change.
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Enigma VHDL

Enigma machine diagram

A gate-level Enigma cipher machine in VHDL. Automated testing uncovered two bugs that had been hidden for nine years, both now fixed and pinned down by 241 exhaustive checks.
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