Re: SCSI terminator required

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Article #34202

#34202

From: Tom Bird
Date: Wed, 21 Apr 1999 00:00

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In article <661106854wnr@ttelmah.demon.co.uk>, Roger J.Hamlett
<Roger@ttelmah.demon.co.uk> writes
>In article: <qN$EETAUs6G3EwwD@dbqa.demon.co.uk>  Tom Bird 
><hamster@nospam.demon.co.uk> writes:
[snip]
>> What's the difference, active, passive and so on?

>+5v (TERMPWR)---220ohm---signal---330ohm---GND

>+5v(TERMPWR)---2.85v regulator---110ohm---signal

>This gives a large degree of immunity to noise and droop on the 
>termpwr line, and a better impedance 'match'. Active is _required_ on 
>any bus using the 20MHz signalling rates (ultra), and recommended 
>even at the 10MHz 'Fast SCSI-2' rates. I can make a suprising 
>difference to bus reliability...

Thanks for the information.

The SCSI bus inside my main PC is terminated by a CD-ROM, would this be
active termination?  It does have a 10MHz device (hard drive) and will
shortly (probably) get another one, most likely a 7200RPM 20MHz device.

TB

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From: Tom Bird <hamster@nospam.demon.co.uk>
Subject: Re: SCSI terminator required
Date: 1999/04/21
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