started new topic here becasue no one answered
Is it possible to get the original diablo last patched version v1.09 (available here on GOG) working with belzebub. I notice you can save with this version but I like the HD improvement provided here.

Yes.

Can you tell me how?

I have Belzebub installed and it launches from the desktop shortcut and I have played it some but not much.

I don't remember if there were any "hoops" to jump through when I first installed Belzebub so I suppose all there was to it was download the mod, copy the files to GOG's Diablo directory and if it hadn't already create a shortcut and put it on the desktop.

The only file Belzebub needs from the original Diablo installation is DIABDAT.MPQ. While the setup instructions say to copy the Belzebub files into your Diablo folder, I prefer making a separate folder for just Belzebub and copying DIABDAT.MPQ there.

I have tried both above methods and unfortunately it doesnt seem to work. Belzebub patches up and the game works but the option to save during game is lost. I dont know if theres anything else I could try?

Belzebub does not support directly saving the game -- it works like Diablo II and constantly saves your character but not the state of the game world. That's a "feature" of the mod.

Basic HD support is there, but not ready for release yet since there are still some UI issues:
https://github.com/diasurgical/devilutionX/pull/361#issuecomment-541973714