[rescue] Mac IIfx compatible NuBus video card.

gsm at mendelson.com gsm at mendelson.com
Sun Nov 8 11:22:35 CST 2009


On Sun, Nov 08, 2009 at 11:24:06AM -0500, Mark G. Thomas wrote:

>So, now I've got a working ethernet card, I'm trying to do something 
>useful with the IIfx.

I found this nosing around the Apple web site:

http://support.apple.com/kb/TA42169

   Why Is There A New Black Terminator For The Macintosh IIfx?
   ===========================================================

   One of the features of the Macintosh IIfx is a new SCSI chip that
   provides SCSI data transfer rates up to 3MB per second, faster than any
   earlier Macintosh systems. To achieve these transfer rates, components
   on the Macintosh IIfx logic board are smaller and faster, this makes
   them more susceptible to signal reflections on the cable. The new
   terminator adds the filter capacitors and changes the resistor values
   for some of the signals to reduce the reflections.

This originally was from 1992, when 3MB per second was fast. I wonder if later
SCSI terminators designed for 5MB or faster SCSI would work?

There are also several warnings that you should only have 1 black terminator
on a chain, even with a IIfx. 

Geoff.

-- 
Geoffrey S. Mendelson, Jerusalem, Israel gsm at mendelson.com  N3OWJ/4X1GM



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