The bus in a PC is the common hardware interface between the CPU and peripheral devices. Parallel buses with multiple lines (wires) were superseded by serial versions, which use one line for data.

AMD's new Strix Halo uber APU for laptops was already pretty interesting, what with its 256-bit memory bus and monster sized ... adding some trick tech to its CPU dies in the process.

Building a CPU out of logic gates is a great way to learn ... I/Os are limited to simple eight-bit input and output buses, but a sixteen-bit address bus gives it plenty of space to add ROM ...