3rd Generation computers (~1965 to ~1975) was a short-lived period where computers used advanced IC chips, but did not use a dedicated single CPU chip. Instead the “CPU” was typically a circuit board or two consisting of many discrete logic IC’s which formed the Algorithmic Logical Unit and supporting steering logic. The pdp-8 being a fine example, where a single PCB contains many 7400 logic IC’s including four 4-bit ALU’s to form a complete CPU with Opcode decoder and basic registers. With the introduction of the first CPU IC in 1971, being the Intel 4004, the only advantage of a discrete logic CPU board was the lower cost. It was not long before the CPU IC became cost-effective, and the 3rd generation computers were surpassed.