3850 Microprocessor Family: The 3850 Family, introduced by Fairchild, is also know as the F8. The F8 is a two chip processor implementation designed for I/O intensive applications. The F8 is an 8 bit nMOS processor with 16 bit address bus and 76 basic instructions in the instruction set. The heart of the system is the 3850 CPU combined with the 3851 Program Storage Unit (PSU). Some of the CPU registers, for instance the program counter, that are usually part of the CPU on other systems, reside on the PSU in the F8 system, Some of the I/O ports, which would be on a seperate chip on most systems, is part of the CPU in the F8 system. This arrangement reduced the number of required interconnects and reduced chip count of the F8 compared to its competitors at the time. Pictures below show a Fairchild F8 evaluation kit.