The Model F was a series of computer keyboards produced mainly from 1981–1985 and in reduced volume until 1994 by IBM and later Lexmark. Its mechanical-key design consisted of a buckling spring over a
Model F capacitive pads from an opened assembly
Corrosion occurring on a Model F 122 terminal keyboard along with dust
A comparison between a Model F spring (left) and a Model M spring (right); the Model M uses a spring with fewer windings and smaller plate for the plastic membrane underneath.
IBM Model F 122 key Keyboard
The IBM Personal Computer, often referred to as the IBM PC, is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 1
Model F keyboard
…used a membrane in place of the PCB. The Model F first appeared with the IBM System/23 Datamaster all-in-one computer. It is best known as part of the IBM Personal Computer in 1981 with some keycap label differences, and its subsequent release with the IBM Personal Computer/AT, where it was reconfigured with the AT protocol…
Internal view of the IBM PC (from the back), showing components and layout. This PC has been outfitted with aftermarket floppy and hard disk drives, but the motherboard and most of the expansion cards are stock.
Original IBM PC motherboard with 16 KB RAM soldered and 48 KB socketed, for a total of 64 KB onboard
Later IBM PC motherboard with 64 KB RAM soldered and 192 KB socketed, for a total of 256 KB onboard