Buchla CV question

[Haible Juergen]

I don't know much about Buchla modulars, so I may be
very wrong here. Apparently he used separate CV and
audio connections (different jacks).
I noticed diodes in some CV output circuits I've seen.
Could it be that the philosophy was to have
a kind of "analogue wired-or" function, where the
current *maximum* of all CVs would be used, rather
than ordinary mixing / addition ?
Or was it ordinary mixing when searate input jacks
were used, but maximum function when both sources
were plugged into the same input jack ?
Related question: Were the Buchla CVs generally 
unipolar (positive only), or were there bipolars
CVs as well ?

JH.