Editing MOS Technology 6522 (section)

{{Short description|Microprocessor I/O port controller IC}}
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[[Image:6522 VIA Pinout.svg|thumb|250px|Pin configuration of the 6522 VIA]]
[[Image:Rockwell R6522P Versatile Interface Adapter.jpg|thumb|250px|Rockwell 6522 VIA]]

The '''MOS Technology 6522''' Versatile Interface Adapter (VIA) is an [[integrated circuit]] that was designed and manufactured by [[MOS Technology]] as an [[I/O port]] controller for the [[MOS Technology 6502|6502]] family of microprocessors. It provides two bidirectional 8-bit parallel I/O ports, two 16-bit [[timer]]s (one of which can also operate as an event counter), and an 8-bit [[shift register]] for [[serial communication]]s or data conversion between serial and parallel forms. The direction of each bit of the two I/O ports can be individually programmed. In addition to being manufactured by MOS Technology, the 6522 was [[second source]]d by other companies including [[Rockwell International|Rockwell]] and [[Synertek]].

The 6522 was widely used in computers of the 1980s, particularly [[Commodore International|Commodore]]'s machines,<ref>[https://web.archive.org/web/20130527075058/http://old.htu.tugraz.at/~herwig/c64/via.php The [Commodore<nowiki>]</nowiki> 1541 floppy disc drive has two chips of the type MOS 6522...] {{dead link|date=November 2015}}</ref> and was also a central part of the designs of the [[Apple III]], [[Oric-1]] and [[Oric Atmos]], [[BBC Micro]], [[Sirius Systems Technology|Victor 9000/Sirius 1]] and [[Macintosh|Apple Macintosh]]. Video game platforms such as the [[Vectrex]] also used the 6522, as did the 1984 through 1989 Corvette digital dash cluster. A high speed, [[CMOS|CMOS version]], the [[WDC 65C22|W65C22]], is produced by the [[Western Design Center]] (WDC).