Most CPUs have a number of registers which store small amounts of data that the CPU is processing. In our simple breadboard CPU, we’ll build three 8-bit registers: A, B, and IR. The A and B registers are general-purpose registers. IR (the instruction register) works similarly, but we’ll only use it for storing the current instruction that’s being executed.

Videos

Schematic

(coming soon!)

Parts list

QuantityDescription
3Breadboard
674LS173 (4-bit D-type register)
374LS245 (Octal bus transceiver)
16Red LED
4Yellow LED
4Blue LED