Just to get my solution into the archives, what I wound up doing was 
re-numbering my SCSI drives so the NetBSD drive was numerically lower.  
Apparently my cheap (SIIG) SCSI card only tries to boot from the first 
drive found, instead of having some other method of signifying which 
drive should be the boot device.

Oh well, I'm now happily dual-booting, on my way back to being a 
Unix-only user again.

Cheers!
-- Tracy Nelson

David Laight wrote:

>On Sun, Jan 30, 2005 at 09:08:13PM -0600, Tracy Nelson wrote:
>  
>
>>I recently installed NetBSD 2.0 on my machine.  However, when it boots 
>>it doesn't come up with a boot manager, it just goes straight into 
>>Windows.  My guess is this has something to do with the fact that my 
>>boot drive is IDE, and I installed NetBSD onto a SCSI drive.  However, 
>>when I try to boot from my SCSI card, it says that no OS can be found.  
>>I'm guessing this is because I have two SCSI drives, and NetBSD is 
>>installed on the second one (ID2, with ID1 being my Windows D: drive).
>>    
>>
>
>Looks like you bios is always booting bisk 0x80 (in bios numbers).
>You need to put something into the MBR of that disk to allow the other
>disk(s) to be booted.
>
>  
>
>>Any suggestions on how I can boot into NetBSD?
>>    
>>
>
>Boot the NetBSD install CD, when it comes up in systinst type x (or ^C).
>That should give you a root prompt on the install kernel (etc).
>
>Run 'fdisk wd0', select 'n' to the question about bios geometry, then
>edit your windows partition, type enter to the partition type and size
>(this leaves them unchanged), but enter a short name for the 'bootmenu'.
>Exit saving everything and it should ask whether you want to update the
>mbr code - which you do.
>
>Now, when you boot disk0 the netbsd mbr code will give a menu (with one
>entry for windoze), but you can hit the Fn keys to boot the mbr of
>a different disk.  I think F3 will boot the disk you've got netbsd on.
>(The bios must have given it a number or else you couldn't have installed
>on it.)
>
>If you go down the grub route, you'll find that it need to squirrel
>stuff away in a filesystem somewhere.  The netbsd mbr bootselect code
>sits entirely within the first sector.
>
>	David
>
>  
>