I used to have a commercial 8748.... programmer, it came with an ISA card and an external box with a 40-pin ZIF, connected by ribbon. Unfortunately I managed to lose the ISA card somewhere along the line(probably just left it in an old PC that was thrown out) although I do still have the ZIF box and cable which I can re-use.

My motivation for getting the old 8052AH-BASIC to program 8748's is akin to restoring a vintage car - of course there are better ways to do it now, but I like the idea of seeing the old chip finally work. It has been sitting in the parts bin for over 20 years and getting it to do something useful will be rewarding.

It should be pretty straightforward - a '373 for the address latch, a 32kx8 SRAM (overkill, but I've got a spare one) a bit of glue logic and some discrete voltage shifting stuff for the programming pins. I'll post the finished schematic when it all works.

Geoff