How can I boot dos from HD and still run Microport 3.0e?

[james_jim_woomer at cup.portal.com]

I would like to boot DOS from my HD and also run Microport 3.0e
How can I:
1. Boot UNIX from HD and also boot DOS from HD also
   (Using fdisk to change the active partitions, perhaps?)
   OR
2. Boot DOS from HD and UNIX from floppy
I quess its understood that I'm running a 386 AT. Ive got 80 MEGs
with a full DOS partiton and the rest is Microport. My thanks in advance.

Jim Woomer