The PLA20V8 is aPLA that consists of two GAL20V8B chips from Lattice Semiconductor. The GAL isa programmable logic chip that looks a lot like the original PLA: It has an ANDarray, followed by an OR array. Depending on the mode of the GAL the signalthen can go through a flip-flop, which the PLA does not have, but thisflip-flop is bypassed in the so called "simple" and"complex" modes, which makes the chips rather close to a PLA, perhapsthe closest possible chips to a PLA you can get. There are two GALs, because thelogic will not fit in a single GAL.
EACH BOARD IS COMPLETELY ASSEMBLED, TESTED and READY FOR FREE IMMEDIATE SHIPMENT FROM THE USA!
HOW GOOD IS IT?
Yes, it worksfine. The Epyx Fast load cartridge is a rather questionable design thatperforms analog tricks on digital lines. In order for the Epyx Fast load towork, a PLA needs to have similar analog properties and be stable at the bordervoltage between 0 and 1. This is the case for this GAL based PLA replacement.
Please notethat the pins on this device are a little larger than a regular IC chippin. As such, we recommend strongly thatthe 28-pin Wide DIP socket be upgraded to either a round machined pin type or adouble-wipe design. The existing factoryDIP socket is rather terrible and can in some cases (due to ageand bending of contacts) NOT produce enough contact for this or even an originalPLA chip to function. It WILL function in the factory socket, but it is a little tight. The newer socketswork better with the larger pins on this module. Save yourself time and upgrade the socket!!
READY FOR IMMEDIATE FREE SHIPMENT!!