8255 is a programmable peripheral device, a chip used to control peripheral devices connected to/with in a computer in the 8086 based machines. It's a general purpose i/o controller, produced by Intel. More details: http://www.electronics.dit.ie/staff/tscarff/8255PPI/8255.htm http://www.wantronix.de/pdf/decision/8255pci.pdf

The Intel 8255 is a general purpose programmable Input/Output device which is designed for use with all Intel and most other microprocessors. It provides 24 Input/Output pins which may be individually programmed in 2 groups of 12 and used in 3 major modes of operation.

In MODE 0, each group of 12 I/O pins may be programmed in sets of 4 and 8 to be inputs or outputs. In MODE 1, each group may be programmed to have 8 lines of input or output. 3 of the remaining 4 pins are used for handshaking and interrupt control signals. MODE 2 is a strobed bi-directional bus configuration.

The 8255 is a 40 pin integrated circuit (IC), designed to perform a variety of interface functions in a computer environment. The 8255 wasn't originally designed to be connected to the Z80. It was manufactured by Intel for the 8080 microprocessor.

Neither the 8155 nor the 8255 are considered to be microprocessors.

The 8155 is an integrated RAM, IO, and Timer device designed for the 8085. The 8255 is an Programmable IO controller.

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The Young and the Restless - 1973 1-8255 was released on:

USA: 3 November 2005