Anybody recognize a 40-pin IC marked PT1482B-01?

Each IC is marked with a manufacturer's logo that's a small circle in the
middle of an "integral" sign (elongated S).  Might be Siliconix (or maybe
WD).  Date codes range from '79-'81 on the board I have which has 18 of
these beasts.  There's a raised center section, ~1cm square with a round
circle in the middle.  It's covered over with a paint/tar compound;  I've
scraped it off and the round circle is definitely not a "quartz" window but
just a round depression in the center.   The underside of the IC indicates
that it was manufactured in Malaysia.  The underside is also marked
AA1482-B00 with a lot and date code that doesn't agree with the one on the
top.

In addition to the 18 1482's, there are 9 DS8820 and 9 DS8830 IC's (Dual
Differential Line Drivers and Receivers) and a scattering of TTL "glue",
mostly 'LS02 & 'LS04.  My first guess was that they were (OTP) PROM IC's
but I don't think there's be line drivers and receivers servicing ROM so
it's more likely to have been some kind of read/write memory.  Also, having
that many of them on one wire wrap board with wiring that looks like at
least some of the pins may be bussed suggests to me that it's not likely
anything but memory.

It's not likely that any memory from circa 1980 would be all that useful,
but I'd like to know just what they were before I trash them.

    Thanks in advance for any suggestions

        Norm