As others have said, this pre-dates RISC-V. The author built it as a teaching / learning aid and blogs about it excellently: https://zipcpu.com/ https://zipcpu.

As others have said, this pre-dates RISC-V. The author built it as a teaching / learning aid and blogs about it excellently: https://zipcpu.com/ https://zipcpu.com/ More generally, anyone building their own CPU and architecture just for kicks gets serious kudos in my book. It's not a shame, it's brilliant!