[philzook]

It's a really neat board. You can get kits from aliexpress etc. I wrote up some notes here https://www.philipzucker.com/td4-4bit-cpu/ . English descriptions are not so readily available.

I also had some fun modelling the chips in verilog and model checking a verilog interpreter against them. https://www.philipzucker.com/td4_ebmc/ George Rennie got a similar thing working using the yosys toolchain https://github.com/georgerennie/philip_zucker_sby_demo

[NooneAtAll3]

Huh, so its isa is just "Dst := Src+Imm", with Dst one of [A,B,Out,PC] and Src one of [A,B,In,Zero]

Plus just a tiny bit of logic that wires in "Carry Flag" when Src=Zero to control Dst=PC

I guess "MOV A,B" sets Imm to zero for simplicity, because I don't see anything stopping it

[drzaiusx11]

I just translated the entire book into English via multimodal LLM, which with my (rusty) Japanese language knowledge looks largely correct (including diagrams and manga text.)

I'm not sure of the legal ramifications of this but if anyone shows me their original PDF receipt from the Japanese publisher's website I'd be willing to share it under the conditions you don't publish or share it anywhere publicly...

[drzaiusx11]

My contact info is just my user name here + the common Google provided domain name