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Looking for programming algorithm for Harris 7685 PROM



Jan 1, 1970
i have to program some PROMs for a HAM-Radio equipment. I have
M3-7685-5 PROMs (2048x4) from Harris which are pin- and read
compatible (but not write compatible) with 82S185 and others.

But, because i have no PROM-Programmer, i will build one by myself. So
i am looking for a Datasheet or/and a specification of the programming
algorithm for the Harris 7685 PROM.

Is anyone out there who has an old Databook from Harris ?
Many Thanks. Michi


Jan 1, 1970
That brings back old memories. All of our old Harris data books have
been trashed. Harris had a big problem with all of their PROMs: they
grew back after programming. We quit using them for that reason.

The first Data Books from Harris gave instructions on the programming
protocol. The book indicated that these were the easiest and most
forgiving devices (as far as programming parameters) in the industry.

These PROMs were the opposite of convention: they were shipped all ones
vs all zeros. The later data books indicated that the programming
parameters were more critical. At the end even Harris was unable to
supply us with programmed PROMs what did not grow back.