Hi, folks;  I'm looking for an unusual PROM.  A palmtop I have, uses a
    pair of TSOP 48-pin mask ROMs, that just have OEM numbering on them;
    some day I'd like to EnROM a newer DOS or perhaps ELKS (8086 Linux
    clone), if possible.  I don't know who made the ROMs, I don't recall
    seeing 48-pin TSOP ROMs before today!

Well, flash memory is very commonly available in that sort of configuration,
and is easilly usable in OTP-mode...

BillW