Custom 16-bit CPU

A basic computer, rewired in Logisim to run one loop

The classic basic computer, redesigned in Logisim for Computer Organization. The assignment was a small C loop — a few adds, an AND, a multiply, repeated three times — and the job was to build a machine that runs it. That meant a trimmed instruction set of seven opcodes, including a new MUL, and a hardwired control unit that goes straight from fetch to execute because indirect addressing was dropped. The loop runs from machine code preloaded into memory, with ISZ counting the iterations.