I finally built a rig to dump the Sharp SM5s in the G&Ws that I have. It's a little messier than the TMS1000 dumper because along with level-shifting (this time down to 3V instead of up to 9V), you have to force opcodes into the same port that you get the dump out of. I found a neat hack using the IDT QS3861, and I also had to use a CD4049 for the OSC. The PIC monitors one of the S lines to sync the 4x OSC input to the internal instruction clock. I capture everything with a Logic 16, then process the exported file to get the dump.
There are a couple of things that are a little different from what Igor told me about the Russian chip, but overall it worked like he said. I had figured out that making the T input high would output the current bank of 63 bytes (usually the reset page 55) to the S bus, but I didn't know that when you made K1 high, you could input opcodes over the S bus. Igor said that you had to invert the opcodes (like you have to do for the 3870), but I found that I had to leave them alone. He didn't tell me a specific opcode to use; I chose TL. When I send those 2 bytes then drop K1, the ROM dump starts 8 bytes into the page for some reason. I clock 55 more bytes through to get back to the beginning, then capture the next 63 bytes. Then I compare the next 63 bytes to the previous, then increment the page and loop back to force the new TL opcode.
Page 55 of the resulting dump matches what I see when I do a simple capture without forcing in opcodes, so I'm pretty confident of it. I used unidasm on the output, but I don't know SM5 well enough to tell if it makes sense.
I've only dumped Boxing (BX301) so far, since I already had it apart from when I experimented on it before. I've got the PCB for Donkey Kong II (JR55) that hap sent me, but it will only dump the lsb; the others remain high all the time. I guess I'll decap it and visually read the bits. I've also got just the PCB for Mario Bros (MW56) from Incog, and I bought the complete games Cement Factory (M102), Blackjack (BJ60), and Bombsweeper (BD62). Hap recently sent me DK JR (DJ101). I also have the Nu, Pogodi that Tauwasser sent me, and just the LCDs for Mickey and Donald that Lord Nightmare sent. Blackjack and Bombsweeper have 80 pins, so I assume they are SM512s.