One thing I don’t like about From NAND to Tetris is that they don’t explain sequential logic, like at all. They basically say: “Here’s a D flip-flop, don’t worry about how it’s built”. They confine a vague understanding of it to a technical note and call it “conceptually confusing”. That just contradicts the whole premise of the thing though. They say you can build everything from NAND and then they just throw in a new building block without explaining how it’s built from the building blocks they already built up.
Simon has been looking at what stages the project would involve and what hardware he would need. Like looking up breadboards on the BusBoard.com site, aren’t these BBs cute?



I need to create a CPU (including memory). Also need to make an IO manager and the IO itself (a keyboard interpreter and a video card). IO means input-output, so keyboard-screen. That’s only the hardware. For the software, I need to make a compiler, a VM translator and an assembler.

He has also been busy constructing the ALU of the hack computer in Logisim:
