Mononymous developer Pepe has constructed simply concerning the easiest processor you are prone to discover, impressed by the Motorola MC14500B: the one-bit, five-transistor PCPU-NANO1 — and, for good measure, constructed an working system appropriate with a protoboard implementation.

“[The PCPU-NANO1 is a] minimalistic one-bit CPU constituted of NPN transistors and resistors,” Pepe explains of the gadget, which is constructed utilizing 5 particular person transistors. “It requires an exterior program counter, registers, and clock.”

It is likely to be onerous to see how a five-transistor gadget could possibly be termed a “central processing unit,” however Pepe’s mission takes its inspiration from a industrial product: Motorola’s MC14500B Industrial Management Unit, a equally one-bit processor launched by the corporate in 1977 and which wasn’t discontinued till 1995.

The place the M14500B supported 16 directions, although, the PCPU-NANO1 solely helps two: NOP, a null no-operation instruction; and NADJZ, which NANDs enter and information and jumps if the result’s zero. It is restricted, then, however that hasn’t stopped Pepe writing an working system for the processor — utilizing an Arduino UNO R4 Wi-Fi to switch the opposite lacking components of the system. “The OS makes use of Arduino as reminiscence,” Pepe explains, “and PCPU-NANO1 because the core for calculations.

The design of the PCPU-NANO1 has been launched on GitHub, with the Nano-OS software program in a separate repository — each made accessible beneath the permissive MIT license.