Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!crdgw1!crdos1!davidsen
From: davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr)
Newsgroups: comp.arch
Subject: Re: Optical Interconnect
Message-ID: <3326@crdos1.crd.ge.COM>
Date: 11 Apr 91 12:55:11 GMT
References: <12618@pt.cs.cmu.edu> <510001@hpsciz.sc.hp.com>
Reply-To: davidsen@crdos1.crd.ge.com (bill davidsen)
Organization: GE Corp R&D Center, Schenectady NY
Lines: 19

In article <510001@hpsciz.sc.hp.com> peng@hpsciz.sc.hp.com (Peng Lee) writes:

| 	On chip A, one can use the liquid crystal to modulate the light.  On
| chip B, one can use the CCD to detect the IR (a very bad idea, someone please
| point out a different way to do it.).

  Why would you do this rather than use an IR LED on the sender chip,
avoiding having to pipe the light through multiple chips? With only a
few levels of ship there would be a power disipation saving, but with
the cube you describe later in your posting I would think the loss of
realestate to windows would be worse than the heat problem.

  Consider this a question rather than a criticism, I can't even
ballpark the tradeoffs in my head, so I don't imply in any way you're
wrong.
-- 
bill davidsen	(davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen)
        "Most of the VAX instructions are in microcode,
         but halt and no-op are in hardware for efficiency"