To be honest with you, athough my HP41CL has the serial connector, I have never used it. I frear too much to block the calculator - and it is a quite expensive machine!
But I have read today in Monte Dalrymple's site that he is preparing a "Flashing the HP41CL for Dummies" document. That'll be ideal for those of us who are not microprocessor programmers like Monte, Diego and others! I look forward to be able to add more images to my system. The good thing is that you can know what's the latest module you have because you can test the modules based on the recording date in Monte's manual - the first missing will show "nonexistent" on your screen - and you need to load modules from that date on"