I uploaded the Little Professor 1978 ROM array pic and ROM dump. When I run the code in an emulator, it gets stuck in a loop. This is likely because opcodes are slightly different from the TMS1000, since the TMS1990 has separate keyboard strobe outputs.
I compared the ROM word address decoder and the ROM page address decoder circuits, and they appear to be the same, so I think the ROM dump is correct. Unfortunately, there is a glob of plastic covering part of the instruction decoder. I just ordered some stronger Nitric acid to help clean dice.
www.seanriddle.com/tms1990.html