Programmable Array Logic (PAL) is a family of programmable logic device semiconductors used to implement logic functions in digital circuits that was introduced by Monolithic Memories, Inc. (MMI) in March 1978. MMI obtained a registered trademark on the term PAL for use in "Programmable Semiconductor Logic Circuits". The trademark is currently held by Lattice Semiconductor.
MMI 16R6 in 20-pin DIP
AMD 22V10 in 24-pin DIP
PAL 16R4 Block Diagram
AMD 22V10 Block Diagram
Programmable logic device
A programmable logic device (PLD) is an electronic component used to build reconfigurable digital circuits. Unlike digital logic constructed using discrete logic gates with fixed functions, the function of a PLD is undefined at the time of manufacture. Before the PLD can be used in a circuit it must be programmed to implement the desired function. Compared to fixed logic devices, programmable logic devices simplify the design of complex logic and may offer superior performance. Unlike for microprocessors, programming a PLD changes the connections made between the gates in the device.
Lattice GAL 16V8 and 20V8
An EPLD from Cypress in a PLCC-package