🚀 go-pugleaf

In a recent article Paul G. Nevai writes:
>For starters, did you know for instance, that
>   Mac -- System Cable -- Hard Disk -- Teminator
>is wrong? The right configuration is
>   Mac -- System Cable -- Teminator -- Hard Disk

I've never found any difference between these two configurations.  Some
hard disks only have one plug, and you have to use the second configuration.

>OK? Now, for advanced intermediates, did you know that
>   Mac -- System Cable -- Cable Extender -- Teminator -- Hard Disk
>is wrong? The right configuration is
>   Mac -- System Cable -- Terminator -- Cable Extender -- Teminator --
>   -- Hard Disk

In fact, the first terminator should be right after the Mac, but it's not
possible to put one there unless you put a terminated hard disk inside (like
a Mac II or SE).  The bus is long enough to want a terminator at BOTH ends
(any long SCSI bus should have a terminator at both ends), but with Apple's
cabling you can't plug a terminator right on the computer (because they
use a DB25 connector instead of the standard).

>Now, for pros, do you know where the terminator goes in
>  Mac -- System Cable -- Cable Extender -- Hard Disk -- Cable Extender --
>  -- System Cable -- Hard Disk ?

Use two, at the farthest ends of the bus you can get to:
Mac - SystemCable - Term - Extender - HD - Extender - SystemCable - HD - Term

>One more questions: why are
>  ... -- Teminator -- Hard Disk (The End)
>  ... -- Hard Disk -- Teminator (The End)
>different? 

They aren't.  Have you ever had one configuration work and the other fail?

>P.S. Though one can have up to 20 feet of SCSI cable in a system, do not
>ever dare to test the limits or else you will have spectacular crashes.
>Trust me.

I run about 10 feet of SCSI cable in my system without problems, but I
wouldn't make it much longer and expect it to work right.
          Lexington Software Design:  Tomorrow's Software Yesterday

Eric K. Olson     olson@endor.harvard.edu     harvard!endor!olson     D0760
   (Name)                (ArpaNet)                 (UseNet)        (AppleLink)