In message <Pine.SOL.3.96.970804103237.1425A-100000@ursa.cus.cam.ac.uk> you wrote:

> > > Has anyone got any experience of CD writers under RISC BSD (or even RISC
> > > OS at a push)? Are there any particular ones recommended or any caveats in
> > > their use?
> > 
> > You cannot do it under RiscBSD running on a RiscPC due to the speed of the
> > drivers unless you have a writer with a build in HD.
> 
> Does this affect DAT drives in the same way then or are they so slow that 
> it doesn't matter? 

I tried with my Exabyte tape which should do 246K/sec - this was too fast 
for my system (SA RPC with Powertec Controller), so the drive stopped 
every two seconds or so. Also, after a while, the task (tar) would usually
hang and refuse to be killed. 

DAT drives (recent ones) tend to be quite fast, ie up to > 1MB/sec, so I 
would guess RBSD is just too slow ATM.

So you CAN of course use a DAT tape under RiscBSD, but it'll probably 
take days for a full backup and will also ruin your drives mechanics.
And I still suspect it's actually the drive causing the hang, something
like it giving up and causing an unexpected condition in the SCSI drivers
(OK, that was way out of my depths :-) ).


> If I get a SCSI tape drive, is /dev/rst0 functional?

Principally yes.

> Any particular recommendations for tape drives?

Hmmm. Helical scan devices (like DAT or my 8mm Exabyte) tend to be more
expensive, but the media cost is usually lower (especially for DAT).

There's a lot of discussion about the merits and problems of helical scan
vs. linear recording devices, but I think much of this is pure advocacy, 
so you can probably ignore it.

There's at least 3 Acorn users with Exabyte 8mm drives, so why not choose 
one of these (if you can get your hands on one) ? They're available
in capacities between 2 and 7GB, I think.

OTOH, they're probably a bad choice when it comes to tape interchange -
so if this is important for you, go for DAT or even choose something 
QIC (read) compatible, ie TR3/4.

Kind regards,

-- 
Thomas Boroske