Recreating VisiCalc in 6502 assembly for the Apple ][+. The latest version of WilliCalc is hosted here - and is fully useable - for your interest, amusement, and productivity.

Trying my hand at 6502 assembly, and putting the 500MHz 6502 through its paces, with (what else?) ray-tracing.

Rewriting everything in C++ achieves a several hundred-fold increase in spead, begetting a monster belonging to alternative history sci-fi: a 500MHz 8-bit CPU.

Implementing low- and high-res graphics modes, allowing the Apple ][ emulator to run all kinds of original 1970s software.

Reverse-engineering the arcane character generation and line interleaving systems on the Apple ][ to produce a working emulation that boots into the original ROM.

Building a cycle-accurate simulation of the MOS 6502 microprocessor using test-driven development against millions of real-world states. Gratification when it successfully runs real assembly code.