Frequently asked questions concerning UltraStor SCSI adaptors.

There have been many postings of the form "SLS can't find my UltraStor
SCSI adaptor".  The same problem also occurs with other available
installation disks.

The following concerns the '14F and '34F adaptors, and may or may not
apply to the '24F.

The problem is that there is a driver for the Accent serial board built
into the SLS and the other distribution disks I know of.

During the early part of booting, Linux does a "roll call" to see what
kind of hardware options are present.  Typically an optional board has
logic to give a predefined reply to a particular I/O command.  The
driver can issue this command to the various I/O addresses where its
board might be, and see whether it gets the expected reply.  If it does
get that reply, it can set itself up to use that address in later access
to the board.

What happens is that the Accent driver issues some kind of command to
an address in the 330h-33fh range in the hope that an Accent board might
reply.  This hits the UltraStor 14F/34F and hangs it.  Following this,
the UltraStor is not detected, and booting completes without any hard
disk drive.  Installation is obviously not possible.

Avoiding this with the '14F is simple - just change the jumpers to use
a different I/O address.  This didn't seem to work with the '34F, as the
address didn't change when the jumpers were added.

The solution, according to UltraStor support, is to make the jumper
changes on the same pins (1-2 and 3-4) of JP3 instead of JP4.  This does
change the address.  I don't know whether this will be changed to match
the manual, or vice versa.  This works on this machine and for others I
know of.

Once you have the system installed, it is simple to rebuild the kernel
without the offending driver by answering "n" at the obvious point in
the "make config" process.  You can then use the default 330h I/O address
without further problems.

The alternative is to get a kernel that works with the default I/O address
from someone.

If you have more questions about this, let me know.

B. D. Elliott   bde@halcyon.com   (Seattle)