I've just tried twice to install NetBSD in a spare partition on a disk
currently containing FreeBSD.  Both times, the installation of NetBSD
clobbered FreeBSD (at least to the extent that it would no longer boot -
I don't believe it had actually overwritten the contents of FreeBSD
partition, since I was careful in specifying cylinder counts, etc).

The FreeBSD partition was in the 2nd half of the disk, and I was trying to
install NetBSD (1.2G) in the first half.  I also had the os-bs boot
selector installed in sector 0 of the disk.  My feeling is that installing
NetBSD is clobbering the FreeBSD bootblocks, or something like that.

Thinking about it now, I don't think I've ever installed a dual boot
NetBSD system (NetBSD and DOS) where the NetBSD partition was the first
on the disk (previously DOS has always been first, and I've noticed that
typically DOS partitions start on the 2nd track).

Is there any problem with a setup where NetBSD is the first partition on
a disk?  Do I have to leave the first track empty?  I thought the first 16
sectors or so of the root partition were left unused to accomodate the
secondary bootstrap.

Can someone explain to me how the disk would be laid out in this kind of
arrangement (ie, where the various boot blocks for the two *BSD's would be)?
I noticed that the boot block stuff changed in NetBSD recently.  Is the new
stuff in 1.2G?  Are there still primary and secondary boot blocks?

That should be enough questions for now!  Thanks in advance to anyone who
can clarify all or some of them ...!

Duncan