I understand. One thought occurs: I assume these are mask ROMs, and so likely unchanged from the AN/UGC-74 original. So, if someone somehow managed to get thei

I understand. One thought occurs: I assume these are mask ROMs, and so likely unchanged from the AN/UGC-74 original. So, if someone somehow managed to get their hands on an AN/UGC-74, you'd feel less bad about engaging in this kind of "sacrificial" action, given it would lack the unique historical association with Space Shuttle. Another thought: maybe there is some way to monitor the signals on the ROM pins non-destructively, by picking up the electromagnetic radiation? I'm guessing the answer is "no", at least not in practice. P.S. You have a typo on the page, at one point you have "AN/UCG-74" instead of the correct "AN/UGC-74". The other three times you mention it, you have it written correctly.