a reply to ISC on 'clarifications'

Stuart Lynne sl at van-bc.UUCP
Mon Feb 8 08:08:03 AEST 1988


In article <783 at bigtex.uu.net> james at bigtex.uu.net (James Van Artsdalen) writes:
>In article <795 at vixie.UUCP>, paul at vixie.UUCP (Paul Vixie Esq) writes:
>> [...]  First, no BIOS drive-type table I've ever
>
>Since the WD1005 has no track buffering, I would not expect it to be capable
>of 1:1 interleave.  Perhaps if the peripheral runs at 12MHz you might be able

The recently announced WD1006 does have track bufferring and reputedly can
give you 1:1 interleave.

>One caveat: I've heard rumors that the buffering hard disk controllers don't
>do much for Xenix.  I've heard this from a couple of places, but not from
>anyone with firsthand experience.  Has anyone actually tried both a buffering
>and nonbuffering controller on the same hardware/software Xenix machine to see
>if there is a major difference?  One of the 386 machine manufacturers has had
>several reports that the WD1007 is no better than a WD1005 with Xenix, and
>there is a comment along this line also in the 386 mailing list.  Does Xenix do
>track-buffering in the kernel?

I'd be *very* suprised if the WD1006 doesn't speed up my 386 system. Right
now I'm running with a  WD1003 at 2:1 interleave. Going to the WD1006 will
allow me to use RLL with 1:1 interleave. The maximum theoretical possible 
disk transfer rate goes from about 240KBS to somewhere around 800KBS. 

Now I have no idea how well the 386 and System V will be able to get that
data from the controller. It could very well be that we're running at top
speed already. 

I won't be trying it for a few months yet though. All that's currently
available is the versions without the floppy controller. I don't mind
turfing out my old controller for a more expensive one but I don't want to
waste a slot on a floppy disk controller :-)

If anyone else has tried the WD1006 let's hear about it!

PS Has anyone tried Unix on the Dyna Computer Systems 386 board? It looks
really nice, and apparently is available at 20MHz at not too unreasonable a
price.

-- 
{ihnp4!alberta!ubc-vision,uunet}!van-bc!Stuart.Lynne Vancouver,BC,604-937-7532



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