@tubetime I'd really like the W variant to use external bubble memory just 'coz 1980s Intel. 🙂

But what the heck is it, only thing I can see is a Japan fab variant mentioned here: https://www.cpu-galaxy.at/cpu/Ram%20Rom%20Eprom/Microcontroller/Intel%208X196%20section.htm Even the 8XC196Lx Supplement PDF linked there does not mention it.