I have finished writing a small assembly language program that probes
for a master ATA/ATAPI device on the ISA secondary IDE channel. It's on
http://homepages.paradise.net.nz/lparkes/ if anybody is interested. I
have used this program to narrow down the problem I am having with
detecting my Seagate ATAPI tape drive, and I can now safely say that the
problem is caused entirely by the NetBSD kernel.

I've hammered on the kernel a fair bit with no luck, so I'm going to
have to start thinking instead.

Cheers,
Lloyd