no I did not hear about GigaDrive from SegaBase, I read about it in EGM, VideoGames & Computer Entertainment and other magazines back in 1991-1993, until the preliminary Saturn info was revealed in summer and fall of 1993. usually if something is widely reported (such as the GigaDrive) there has to be some truth to it. SegaBase merely picked up on it. best thing to do if you doubt somethings existance, is try the internet. google the subject and see what the overall concensous is.
Dural was not the Sega-Nvidia project as far as I know. Dural is the Dreamcast. therefore Dural is also the Katana. they are all the same machine. just different code names. like Nintendo's Project Reality / Ultra 64 / Nintendo 64. they're all one and the same.
Dural/Katana (Dreamcast) ran the Scud Race demo.
BlackBelt of course, was Sega's internal competitor to Dural/Katana/Dreamcast.
does anyone recall the Black Belt HeadQuarters from 1997 ? ...it was basicly a BBS that sprung up shortly after the March 13 BlackBelt revelation by Next Generation Online.
the exact URL was: http://www.geocities.com/~bbhq/index.html
I remember having some interesting discussions there on BlackBelt and Dural....