[comp.sys.next] WrenV caching

pvo3366@sapphire.OCE.ORST.EDU (Paul O'Neill) (02/05/90)

In article <15477@orstcs.CS.ORST.EDU> pvo3366@sapphire.OCE.ORST.EDU (I) wrote:

>.........................I'm guessing that the operating system is
>not telling the Wren V to use its 32k cache buffer.  Anyone know how
>to do this?
>

Well, gosh, it turns out *I* know how to do this. :-)

Take the Product Specification, mix gently but thoroughly with
	/NextDeveloper/Examples/SCSI/sg_example.c
and the result is
	cachecon.c

I just ftp'ed it to the cs.orst.edu archives as WrenV_cache.tar.Z.

Speed of sequential reads measured by the 'disk' program has gone
from 250 KB/s to 350 KB/s.

It looks like it may work on Wren IV's, also.

Now all we have to do is figure out this rotational latency stuff.  Help!!


Paul O'Neill                 pvo@oce.orst.edu
Coastal Imaging Lab
OSU--Oceanography
Corvallis, OR  97331         503-737-3251