The first widely documented BASIC on the Data General Nova platform appears to be Data General Extended BASIC. I can date it to at least 1978 due to copyrights in the manual, but I suspect it was released years before that. Bob Leedom had to have something when he ported Star Trek circa 1974. Does anyone have a reasonable release date for Extended 1.x?
Beyond Extended, were there other dialects from earlier times? The only other BASIC I get hits on for DG is Data General Business BASIC, but that's later, and I believe only ran on their larger platforms?