Len,
The Data I/O Model 29B (and older Unisites) do support the Signetics PLS100 (82S100). However the 29B LogicPak needs some rare adapters. It needs the 303A-001 Signetics Programming Adapter which will do the trick if one has the needed JEDEC file or the Signetics format H&L file.
If you only have equations or a Truth Table, then you also need the 303A-101 Signetics Programming Adapter which will generate a Signetics H&L file. The file format is very similar to the programming sheet at the end of the 82S100 Spec sheet. I'm guessing a JEDEC file from an old version of WinCupl (not the Atmel version) or equivalent will also work.
Someone on the cbm-hackers site recently found a very old version of CUPL at the
Purdue Math Department. Hopefully it has a full device library.
-Dave