He even sells a kit with all parts and schematics included. It's easily one of my favorite projects of all time and has inspired me to continue learning more.
It's not close to MyCPU's level of complexity but is great to get you started.
He has remade a system similar to the core of the great 1970's Xerox Alto / Xerox Star series :-)
I never thought someone would remake a processor this way. I love that kind of madness !
[edit: use the site backup if it fails to load: http://mycpu.thtec.org/www-mycpu-eu/index1.htm ]
https://hackaday.io/projects?tag=CPU (Some are FPGA, most are TTL) Including two risc-v implementations (one seems stalled):
https://hackaday.io/project/18491-worlds-first-32bit-homebre... (No activity for a while now) and https://www.youtube.com/playlist?list=PLEeZWGE3PwbansoxKjjMK...
One I am particularly interested in is the Gigatron:
https://hackaday.io/search?term=Gigatron&category=project%20... (Especially now that there's real IO being hacked in)
Walter gave a talk recently about it: https://www.youtube.com/watch?v=rbaAmnhZAis
Nobody mentions this.
In every wire rat nest CPU picture, there is always several thousand dollars of digilent and HP gear out of the frame.
I believe the first two I saw were MAGIC-1 and BMOW (Big Mess o'Wires). I also really liked the MOnSter 6502, a beautiful board-level reimplementation of the 6502 in surface-mount discrete components, with LEDs on the data lines and optional slow/single-step clocking.
Also relevant: the nand2tetris.org course, and Niklaus Wirth's TRM/RISC-3 (not to be confused with Berkeley RISC-I or modern RISC-V) FPGA implementation. Notably TRM/RISC-3 is incredibly simple but can run the whole Oberon system.
In the modern era, I think FPGAs are the killer platform for computer architecture experimentation. There are multiple free MIPS implementations for FPGA and of course there is great OS/compiler support for MIPS.
This one looks very similar to a 6502, and seems to be much smaller than another semi-famous discrete homebrew computer, http://www.homebrewcpu.com/ --- that one only runs at half the clock speed, but the performance seems comparable.
Here’s a real computer.
(apologies for the self promotion..)
I would imagine now that it's on the front page of HN, that poor MyCPU is now on fire