It's possible to create a combinatorial loop in a 16L8, the output state of which persists after the enabling inputs go away. That part has no registers. The designation comes from the logic array configuration, which indicates it has 8 logic outputs, with 16 possible inputs, of which 8 are feedback from the output pins. If you disable the outputs, then you can gain access to the feedback inputs.

This, however, is a 16R8, which has the same 16 possible inputs to the logic array, but has 8 REGISTERED, hence the 'R' designation, outputs. Pin 1 clocks them, and Pin 11 enables the outputs' tristate buffers.

You can "crack" one, but it's a very tedious process that relies on your ability to stimulate the thing very flexibly. If you use your imagination, and this is often helped with a little knowledge of its function in the circuit for which is was designed.

You can stimulate the feedback inputs by first disabling the outputs, then holding the output enable inactive while you clock the device. That will enable you to "see" the effect of each possible feedback state. Most of the probably will be irrelevant to effects not apparent from leaving the outputs enabled, though some guys like to make their PALs hard to crack. It's seldom worth the effort, though, as it's possible to do it regardless of how hard one tries to obscure the logic.

RE