BG> The EPROMs I had in mind are probably only electrically erasable
BG> (if at all) as they have no window on them.  An EEPROM perhaps?

Most unlikely.

BG> I also presume that some of them are only programmable
BG> the once, and can't be erased after that, right?

Yes, basically just an eprom without the expensive window, and OTP, one
time programable. Thats very common now even with single chip micros.

Gives you the convenient low volume programability, saves
the cost of the expensive quartz window, and you dont have
to fart around getting the old roms back to reprogram them.

Corse its also possible they sent you true roms too.
@EOT:

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