XENIX/DOS Partition help

[Cazier]

We are trying to understand the books that Unisys sent about installing
XENIX on a '386 Unisys machine where DOS already exists. We have
C:, D:, E:, F: partitions made already and want to install Xenix on
E: only within the 33 MB space. The manula does not even hint at that
being possible/impossible. If we have left E: open and we begin installing
XENIX from floppies, where do we answer the question about where
XENIX is installed to E: (instead of C:). Or do I just assume that the
system is smart enough to know that C: is a DOS partition?