hello-world-machine · instrument
← the steps · ← → walks a cycle · space taps and pauses · click on a module opens the step that explains it
The machine has already run the program. What you tap is the trace: in each cycle, the source lights up, the bus shows the pattern, the destination receives. Nothing moves. The pattern is copied. In the echo, each key you press enters drawer 8200h and the board shows the path to the screen.
addressdatabit 1bit 0off
the program, as the person wrote it and as it became bytes
what the board shows
Above, the address bus: 16 wires, blue. Below, the data bus: 8 wires, bronze, with the eight bits visible. Between the two, the modules of Petzold's machine, each with its mathematical label. To the right, the screen, which reads 264 drawers of RAM. In each cycle, at most four things light up; the rest stays off.
Specification: research/a-machine.md and research/a-board-in-plan.md. The trace of this page is the same as the machine in Python produces, cycle by cycle.