🚀 go-pugleaf

In article: <AdJ90OA8qcH3EwdF@dbqa.demon.co.uk>  Tom Bird 
<hamster@nospam.demon.co.uk> writes:
> 
> 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.
Probably not...
Depends on the CD, but many of these have passive terminators. 
Conversely devices like HD's, have tended to come with active 
termination for quite a while. I know only a few, but if you give the 
make and model, somebody may be able to say if your CD has active or 
passive termination.

Best Wishes

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