GEM Program using a mouse

[afotherg]

I have a program using the GEM system (remember that from Digital Research?)

I can get it to run on https://www.pcjs.org/machines/pcx86/compaq/deskpro386/ega/

However, the mouse doesn't work. I've tried running mouse.com (serial 2.5), but still doesn't work.

Any suggestions on what's needed to get this to work?