The Free On-line Dictionary of Computing (18 March 2015):
Programmable Array Logic
(PAL) A family of fuse-programmable logic
integrated circuits originally developed by MMI.
Registered or combinatorial output functions are modelled in
a sum of products form. Each output is a sum (logical or)
of a fixed number of products (logical and) of the input
signals. This structure is well suited for automatic
generation of programming patterns by logic compilers.
PAL devices are programmed by blowing the fuses permanently
Today, more complex devices based on the same original
architecture are available (CPLD's for Complex PLD's) that
incorporate the equivalent of several original PAL chips. PAL
chips are, however, still popular due to their high speed.
Generic Array Logic devices are reprogrammable and contain
more logic gates.