Converting old Pro24III (midi-only) .sng files to .cpr questions

I was messing around with Steem and a version of Cubase Lite 1.0 that sorta works on it. It seems the default file format for that is .all

I tried to load a .sng file into it, but I couldn’t tell if it worked because the screen resolution was weird. I tried saving it as an .all file - it took it – but it’s much smaller than the .sng file (from about 32k to 5k in size) so I’m not sure what happened.

And what was the difference between the .sng vs .all vs .arr files? Anyone know?

And instead of having to mess with old versions of Cubase to bring these file formats into today, wouldn’t it be easier for Steinberg to create a standalone program that simply converts these old formats to .cpr?