Ultra2 transfer mode? Works!

Doug Ledford dledford at dialnet.net
Wed Oct 7 01:09:08 PDT 1998

Michael Kunze wrote:
> Greg Hutchison wrote:
> > I just sorted this out here this morning on three separate systems with
> > pre-15 and IBM Ultrastar drives.
> > Drives are variously FastWide (Ultrastar XP and 2XP) and Ultra Fast Wide
> > (Ultrastar 2XP and Ultrastar 9ZX).
> >
> > Two of the systems are ASUS P2B-DS's with onboard AIC7890 controllers,
> > the other uses an onboard AIC7880.
> >
> > In all case with pre-15, the IBM drives were reporting as Wide/Async
> > where other drives (Quantum Atlas) were reporting Wide/Sync.
> >
> > Jumpering all the Ultrastars to 'Disable Target Initiated Synchronous
> > Negotiation', (forcing the initiator to negotiate for Synchronous and/or
> > wide transfers), corrected the behavior of the pre-15 driver - all
> > drives are now reported as Wide/Synchronous at 20Mb/s or 40Mb/s as
> > appropriate.
> >
> > Earlier revisions of the driver behaved differently. Some negotiated
> > sync/wide UNLESS tagged queuing was turned on.
> >
> Greg,
> you are totally right here! After rejumpering the disk, i get wide/synchronous
> transfers at 80 MByte/sec.
> Nevertheless, Doug should do something on that funny driver behaviour as
> generally disks are jumpered to allow target initiated synchronous
> negotiation.

I've uploaded a pre16 that should fix this problem.  Please let me know if
removing these jumpers (or putting them back, whichever it is) makes the
problem come back or if it stays gone.


 Doug Ledford  <dledford at dialnet.net>
  Opinions expressed are my own, but
     they should be everybody's.

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