Cosa (chi) è Fairchild F8 - definizione
![KB]]}} 8-bit personal computer which interfaced to a Teletype. The design permitted additional interfaces to floppy disk and other devices. A program called Fairbug, which resided in a 1K PSU, allowed users to view and change memory and registers, and test programs written in the machine code. This device appeared at the beginning of the transition from time shared computers to personal computers.](https://commons.wikimedia.org/wiki/Special:FilePath/Fairchild F8 Single-Board Microcomputer, year 1975.JPG?width=200 "KB]]}} 8-bit personal computer which interfaced to a Teletype. The design permitted additional interfaces to floppy disk and other devices. A program called Fairbug, which resided in a 1K PSU, allowed users to view and change memory and registers, and test programs written in the machine code. This device appeared at the beginning of the transition from time shared computers to personal computers.")
![Fairchild 71C at the [[Western Canada Aviation Museum]], [[Winnipeg]], [[Manitoba]] in [[Canadian Airways]] livery](https://commons.wikimedia.org/wiki/Special:FilePath/Fairchild 71C.JPG?width=200 "Fairchild 71C at the [[Western Canada Aviation Museum]], [[Winnipeg]], [[Manitoba]] in [[Canadian Airways]] livery")
![Fairchild PT-26B Cornell in flying condition at the [[Commonwealth Air Training Plan]] Museum, [[Brandon, Manitoba]], 2005](https://commons.wikimedia.org/wiki/Special:FilePath/Fairchild Cornell.jpg?width=200 "Fairchild PT-26B Cornell in flying condition at the [[Commonwealth Air Training Plan]] Museum, [[Brandon, Manitoba]], 2005")
![Fairchild F-11-2 on display at the [[Western Canada Aviation Museum]], [[Winnipeg]], [[Manitoba]] c. 2007](https://commons.wikimedia.org/wiki/Special:FilePath/Husky.JPG?width=200 "Fairchild F-11-2 on display at the [[Western Canada Aviation Museum]], [[Winnipeg]], [[Manitoba]] c. 2007")
Wikipedia
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 1 KB of program ROM and handled instruction decoding, and the 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 an 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. 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 but saw less use as a CPU in general-purpose computers. It is relatively obscure today, as its embedded uses rarely revealed the F8 inside.
In 1977, Mostek released a greatly improved single-chip implementation, the Mostek 3870. It merged the 3850 and 3851 and reduced the number of power supply voltages. More important, Mostek re-arranged the assembly line so user code in ROM was added at the last step, greatly reducing the cost of customizing the design for controller use. The 3870 replaced the original Fairchild versions and was produced by several companies in the US and Europe. In Europe, STMicroelectronics continued producing variations of the design into the mid-1990s.
