I have TG77, but don't remember I have seen a bar-display for MIDI in. Well, in DEMO song mode yes but not otherwise.

I'm using it with DX7II (among others) and am missing only the floppy drive. I made a PC DOS program which converts SY-77 files to MDR2-files (DX7II-FD with E!) so I can load the SY77 sounds to it from my DX7IIFD with E!.

But the best is to use some Windows editor/librarian (I recommend one from MidiQuest, haven't used the editor yet though).

The thing I like(d) in TG-77 was the 8 individual outputs (mono) in addition to the two stereo pairs with effects).

VP