Peripheral Interface Adapter

The MOS Technology 6520 is a Peripheral Interface Adapter (PIA ) of the company MOS Technology in NMOS technology. He is a typical Parallel-I/O-Chip for microprocessor systems. Known PIA types are next to, for example, the Motorola MC6820 and MC6821 or the Intel 8255th all have the same functions but slightly different electrical properties. The PIA usually come in a 40 -pin DIP package.

The PIA has been designed to allow easy integration into bus systems around the Motorola 6800 and similar processors. It provides 20 I / O lines that are divided into two 8-bit bidirectional buses and four control lines. The 8-bit buses may be used as an independent individual lines 16, i.e., the direction of data can be controlled individually for each data direction register bit. The control lines can be used to produce hand shakes and interrupts, or simply provide only high or low level.

He became known through use in the Atari 800 family, where he worked for four joystick ports.