Your MCS-48 stuff is really cool. I don't have anything to add to the division topic, but I'v been working on a reverse-engineering project on an MCS-48 based engine management computer from the Porsche 944 Turbo (https://jhnbyrn.github.io/951-KLR-PAGES/).

You probably have the official User's Manual already, but there's a link to it there if you don't. I found it essential in addition to the assembly code manual.

I haven't found much '48 stuff out there so I'm looking forward to reading all your stuff on this!