TP> Quite possible...but all 27 series I've dealt with were UV
TP> erasable but this chip doesn't have a window. I'm lost now.

LE> OTP EPROM (One-Time-Programming) for sure. It's a normal EPROM but it
LE> is in a plastic case with no window so can't be erased. Very commonly
LE> used in modern equipment, for some weird reason, perhaps they're cheaper.

Aint no perhaps about its, significantly cheaper.

When few of the eproms that get out into the field ever get erased
and reprogrammed, its no surprise that the OTP format is common.
@EOT:

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