Nick’s Open 7400 competition entry is an FPGA that is implemented in 7400 series discrete logic ICs:
Building a microcontroller or CPU out of discrete logic is a popular hobbyist pursuit, and it serves a useful purpose. Building a CPU from scratch teaches you a lot about CPU architecture and tradeoffs; it’s an interesting and instructive exercise. So, I wondered, wouldn’t building an FPGA out of discrete logic be similarly educational? Hence, my competition entry: an FPGA (or rather, a ‘slice’ of one) built entirely out of discrete logic chips.
Check out the video after the break.