This was originally made for CS2 and CB2, but later back ported to Diamond customers for a fee and then later he just started throwing it in with Diamond for free. TVEC4 basically is a lot like TVEC3 but adds a pattern editing and playing mode, I think maybe a better way to edit the micro tuning capabilities. (shrug) TVEC3 consolidated the various articulations and section sizes into a single keyswitched instrument accessing samples in a way that previously required you to figure out which specific NKI to load for each articulation or section size or variation. Things have changed a lot and in a bit of a haphazard manner and not everyone will even have the same dir folder structure on the dir system after interacting with Kirk a few times directly. I couldn't find old emails, but looking through stuff refreshed my memory.
