This paper describes the experiments for fourth year students of Department of Control andInformation Systems Engineering, Kurume National College of Technology. The students constructsimple CPUs named the revised TD4 on breadboards. The original TD4 is a 4-bit CPU, and consistsof logic elements, switches, LEDs, capacitors, and resistors. The TD4 has 16 Bytes of memory with16 DIP switches. The revised TD4 utilizes SRAM instead of the DIP switches because the formerneeds less wires and a narrower space than the latter. Each CPU is assembled by one or twostudents, and the experiments last six weeks, 200 minutes per week. The CPU requires twobreadboards; one for the memory part and the other for the rest. Through the experiments, thestudents acquire knowledge of the CPU structure, flows of data and control signals, and how tohandle ICs.