By coincidence I found this interesting 2004 project by Johan van de Pol from TU Delft, The Netherlands.
It uses an 80C32 and an Intersil/Harris 6100 which sharing both the same RAM (multiplexer, page 39/69).
There was a Windows software called PDP8 Control (screenshots page 50) also including a compiler.
I haven’t found more details or full schematics or the software. Does anybody have more info?