Brad has a good start on what looks to be an ambitious electrical engineering project. Inspired by the Apollo guidance computer, he is constructing his own CPU using TTL logic chips and wire wrap. He’s taking a little liberty with the design, using EEPROM chips for opcode decoding instead of hardwiring it all, but I think that can be excused. If you want to follow along and get some tips for your project, he also has a wiki to document his progress.
Building a CPU from scratch