As I understand it, VB 1.0 was effectively QB 8.0, as the last shipment of QB was the QB PDS 7.1. How much did the VB 1.0 codebase borrow from the existing QB implementations? Were they entirely independent projects?
I'm afraid I have no idea on that, sorry! Our team was just involved in VB before it became VB: we did the visual forms editor, VBX interface, and stuff like that. Microsoft then took it in-house and added Basic to it and updated a lot of other things. This article tells about that and may have some insights about the Basic code used: