The PLA20V8 is a PLA that consists of two GAL20V8B chips from Lattice Semiconductor. The GAL is a programmable logic chip that looks a lot like the original PLA: It has an AND array, followed by an OR array. Depending on the mode of the GAL the signal then can go through a flip-flop, which the PLA does not have, but this flip-flop is bypassed in the so called “simple” and “complex” modes, which makes the chips rather close to a PLA, perhaps the closest possible chips to a PLA you can get. There are two GALs, because the logic will not fit in a single GAL.
More info: https://www.freepascal.org/~daniel/c64pla/
