I can tell you that the source is perfectly fine… it’s the port to gcc that caused the glitchiness. And I believe I know who did the port to gcc, and if anyone could do it right, it’s him.
Unless you have the ported code, it’d be a HUGE job to get as far as he did, and then you’d likely still have the same problems, which you’d then have to debug… but I assume he tried to debug it as well as he could, which is as good as probably any of us could.
The official compiler does not generate usable VB binaries, but ISX files, which is the ROM with additional debug information. There are ISX converters for the Game Boy for example, even a homebrew one called abISX, so it should be possible to convert such an ISX file to a playable VB binary. So we’d either have to find official tools to do this task (if any exist) or try for ourselves. The discs come with the two sample programs, if anyone wants to give it a try. The other possibility would be using a VUE-Debugger. As far as I understand, it is possible to compile source directly into a useable ROM using the Debugger, but I am missing the official SCSI interface card, so I am not able to do it. Unfortunately, the card seems to be nearly impossible to find, and any other SCSI card does not seem to work, I tried a few.