Fairchild F8
The Fairchild F8 is an 8-bit microprocessor system from Fairchild Semiconductor, announced in 1974 and shipped in 1975. The original processor family included four main 40-pin integrated circuits (ICs); the 3850 CPU which was the arithmetic logic unit, the 3851 Program Storage Unit (PSU) which contained of program ROM and handled instruction decoding, and the optional 3852 Dynamic Memory Interface (DMI) or 3853 Static Memory Interface (SMI) to control additional RAM or ROM holding the user programs or data. The 3854 DMA was another optional system that added direct memory access into the RAM controlled by the 3852. A minimal system containing a 3850 and 3851 also included four 8-bit data ports, 64 bytes of RAM, and a user program on ROM. This allowed microcontroller applications to be built using just two chips. Doing the same on more traditional designs like the Intel 8080 or Motorola 6800 normally required seven. It also meant that any application that did not fit the simple requirements generally required at least three 40-pin ICs, the CPU, PSU and either the 3852 or 3853 along with additional memory chips. As a result of these tradeoffs, the F8 series found widespread use in the microcontroller market