If the security link is programmed, the things are perfectly reuseable, though you have a big job demystifying them. There could be some registers in use to enable or otherwise influence the outputs that are used. I'd suggest you look at a datasheet and then maybe look at what it's doing in normal operaition with your 'scope. That might reduce your effort considerably.

They're really handy, the GAL16V8's, I mean, in that you can either use the register or not, you can feed back from the pin, or from the register, and you can use a product term to control the output enable, along with numerous other options. In production they cost about what a typical pair of 4-bit counters costs, hence save space, and they drive more and are faster than most HC logic. The only thing I'd have liked is a product-term clock for each register.

BTW, the 16L8, which has no registers, can also have combinatorial-loop-latches, which makes automatic replication somewhat more cumbersome.

RE