I successfully recompiled the kernel on my DS5000/25, and checked
off support for SCSI tape, SCSI generic and "probe all LUN's".
My HP 35470a shows up in the SCSI list of devices at boot, but,
unlike when connected to an Intel machine, it does not get assigned
st0. And sure enough, when I try to do:
mt -f /dev/st0 status or mt -f /dev/rmt0 status,
I see "device not configured".
I also have a TK50 I plugged in, but this is not detected by the
kernel at all. Interesting that the same machine when booting
NetBSD recognizes and works with the TK50 just fine, but refuses
to see the 35470.