install & partitioning advice needed

[baldyeti]

Hello,

Using a FreeBSD 4.6 CD I have, I'd like to install on an
older system (P200). The machine has a 4 GB IDE drive and
another 4 Gb attached via SCSI. These seem to be recognised
as da0 and ad0. The SCSI adapter has no ROM, and is not
directly bootable. I thus suppose FreeBSD - and any OS under
the circumstances - needs at least one little boot slice on
the 1st (IDE) drive. I could free about 400 Mb on that drive,
in an extended partition. Can FreeBSD be started from an
extended partition, or will it need a primary one, and which
filesystem(s) needs reside on the startup disk, with which
recommended minimum size?

TIA,

--bald