(Being a list of projects I'd like to work on some day)

• C62 - expanding my existing C61 design to add useful amounts of program memory and an interrupt system.
• C121 - a 12-bit RISC machine with a fully featured ISA.
• C181 - an 18-bit RISC machine, hopefully resulting in a very fast machine that can compete alongside the fastest TTL CPUs.
• SFZ80 (started designing, but nothing written up yet) - a 20MHz Z80 machine using modern components (other than the CPU, of course) designed for simple expansion and high efficiency.
• A TTL GPU for use with a traditional retrocomputer (fixed pipeline, I expect, but who knows?)
• A serial access vector processing machine based on fast quad-rate SPI memory, resulting in registers that contain effectively arbitrary length data.
• A framework for multiprocessor retro computers - a bus sharing protocol / crossbar system for parallel memory buses, and designs for boards to attach common processors (Z80, 6502, 68000, 8086) to that bus.
• 8086/8, 80186/8, 80286 variants of the SFZ80 project.