I have an Acorn SCSI-1 card as delivered with an Acorn R140.
When I connected an OEM (Apple) Quantum Maverick 540S to this
card and booted RiscBSD, it set this up with synchronous transfers.

Then when booting, the computer would hang at different points
in the boot process, both with auto-build kernels and 4871.

I moved the same drive to the Power-tec SCSI-2, and I haven't
had any problems since.

This indicates that RiscBSD may have problems with synchronous
SCSI on my old 600 with ARM610.

Has anyone else experienced the same problems?

I believe that the reason for using synchronous SCSI with this
combination of drive and host adapter is because that will give
the best performance. The Acorn card is limited to around 1.5 MBytes/s
with asynchronous SCSI, whereas it can handle 4 MBytes/s with
synchronous SCSI. I was therefore delighted that synchronous
SCSI was chosen with this combination since this would give a
higher transfer rate than asynchronous.

So, any ideas?

Kjetil B.