At 9:59 PM -0500 7/24/00, Frederick Bruckman wrote:
>On Mon, 24 Jul 2000, Henry B. Hotz wrote:
>
> > This is hardware and therefore a touch off-topic, but anyway. . .
> >
> > This beast appears to have no SCSI termination power.  Therefore you
> > need something like a Seagate drive on the internal end in order to
> > power the terminators, if any, on the motherboard.  Is there a jumper
> > option on the motherboard to control this?
>
>Any chance you have the terminators on the Quantum backwards? They
>usually have a little mark that lines up with pin 1 on the drive. If
>not that, they used to make active terminators for internal drives.
>It's a 2" x 4" circuit board with a 50 pin male connector, assuming
>you can still find one.

I know which way the terminators are labeled and I had them in with 
the little pin-1 mark next to the arrow on the disk controller card. 
But just for the hell of it I tried putting them in backwards and it 
works now.

The terminator pulls the bus lines to a reference voltage with a 
certain resistance in order to damp out signal reflections from the 
end of the wire.  Since the resister pack is connected to both Vterm 
and Ground reversing the pack should have the effect of shifting the 
reference voltage and increasing the load on signal drivers, but 
should have no effect on the damping, I think.  So maybe this makes 
some kind of sense?

Or maybe these resister packs are labeled backwards.  ;-)

Thanks for the help guys.


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