Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!zds-ux!gerry
From: gerry@zds-ux.UUCP (Gerry Gleason)
Newsgroups: comp.arch
Subject: Fiber channels (was Re: The Killer Micro From Hell)
Message-ID: <94@zds-ux.UUCP>
Date: 10 Jan 90 21:47:14 GMT
References: <34030@mips.mips.COM> <4322@nttmhs.ntt.JP> <39807@ames.arc.nasa.gov> <3101@umn-d-ub.D.UMN.EDU> <40043@ames.arc.nasa.gov> <47800@sgi.sgi.com>
Reply-To: gerry@zds-ux.UUCP (Gerry Gleason)
Organization: Zenith Data Systems
Lines: 35

In article <47800@sgi.sgi.com> rpw3@rigden.UUCP (Robert P. Warnock) writes:
>X3T9.3 is also looking at a Fiber Channel (FC) version of HPPI. At least two
>companies offer single chips *today* which take HPPI-speed 32-bit-word streams
>and serialize them into gigabit/sec bit-serial streams, and vice-versa. The
>holdup right now is affordable fiber-optoelectronics at gigabit speeds, but
>that will change. And in the mean time, people are considering going back
>to *copper* (but still bit-serial to keep the cables small) for "I/O bus"
>distances, since wire is still cheap. [Yes, you can run at 1 Gb/s over cheap
>coax, for some 10's of meters. That's about the same distance as HPPI-PH.]

That reminds me, I've been thinking about the possibility of fiber as a
replacement for SCSI and/or present LAN technologies.  The application
would be more typical desktop micro's, not killer micro's so the bandwidth
doesn't need to be pushing the limits, and cost is a much more important
factor.  To be practical, the implementation would be constrained as
follows:

	1)  Bandwidth appropriate to cheap optoelectronics and serial
	    to parallel conversion.  Preferably a single chip that
	    can directly drive an infra-red LED.
	2)  Bandwidth fast enough to beat (or at least tie) what it
	    replaces (SCSI = 1-40MB/s =~10-300M bits/s >> Ethernet).
	3)  Cheap, simple connectors and cables.  I recently read
	    about plastic fibers, which are thicker so they capture
	    light from higher angles, which should also imply that
	    the connectors don't need to be a precisely made (any
	    comments on this?).

So, is this reasonable?  What are the limits of "cheap" opto-electronics
(for me, cheap is < 10$ for a transmitter and reciever, with an expectation
that it could be 1/10 that for large quantities in a year or two).  If it's
cheap enough it could be applied to interconnecting digital audio and video
components too.

Gerry Gleason