Thanks to David, Michael, Thomas and grsbanks for making all this happen.
I've just done my very first update, from the "stock" 3.0 to 3.4a. Mostly I've been reluctant due to the very quarrelsome win10 and "unsigned drivers" and also, I've had other priorities when at home from work (seaman).
Anyway, I have an older Samsung Netbook from the pre-tab-era which is running the only reasonable win version, namely the 7. It's normally used in conjunction with my 3D-printer (which I've slightly FW-hacked, and therefore refuses to speak with win10) and used that for installing the necessary tools and drivers.
Aaand yes - it went smoothly and very straight-forward.
Also, the HP50G ant the Conn4x will be run on my "legacy" NetBook
This is where announcements of firmware updates for the DM42 calculator will be made