Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!zaphod.mps.ohio-state.edu!
From: lphillips@lpami.wimsey.bc.ca (Larry Phillips)
Newsgroups: comp.sys.amiga.tech
Subject: Re: RS232 gender (was Re: Apple SCSI not compatible with standard SCSI?)
Message-ID: <869@lpami.wimsey.bc.ca>
Date: 4 Dec 89 22:27:36 GMT
Lines: 54
Return-Path: <lpami!lphillips>
To: van-bc!rnews

In <511@shodha.dec.com>, ridder@elvira.cxo3.dec.com (Hans Ridder) writes:
>
> [ chunk of EIA-232 and some comments deleted ]
>
>What I find bizzare here is this concept of an "extension" cable on
>the DTE.  Heck, even the DCE connector "mounted in a fixed position
>near the DTE" is a pretty strange concept.  I *believe* they were
>thinking that all DTE's would have a cable coming out of them with a
>male connector on the free end.  Sort of like the old DEC LA36's and
>VT52's had.  And that *some* DCE's might have such a cable too.

Right.  Or sort of.  I believe (and of course this is my own interpretation)
that the spec is specifically talking about the DCE only, and that there is
really no reference to the DTE, except in relation to the DCE itself.

>You're right, they never get right down and say "the male connector
>shall be associated with the DTE".  But they do say that the DTE will
>be provided with a cable with a male connector.  I would say that the
>connector mounted directly on the DTE is just the special case of a
>zero length "extension" cable.  That, and the stuff in section 3.1.1
>about connectors on "inserted" units sure makes me think they intended
>male connectors to be on DTE's or DTE-like equipment.

That's what I figured. Thing is.. regardless of the lack of spcifics in
defining the gender on the DTE itself, virtually all companies (before IBM
inflicted their PC on the industry), interpreted the spec as being open about
said gender, and most used female on the DTE.

>Anyway, I can certainly see that the words are ambiguous, or at least
>open to some interpretation.  Aren't standards wonderful?  You'd think
>they would clarify things like this, but nooooooooo.  By the way, is
>the text in your copy of the spec any different?

<sigh> Yup. It never fails to amaze me that a standards committee could
overlook something like this, while never forgetting to write in such things as
load capacitance, and writing it in ways that require the engineering
equivalent of a Philly lawyer.  It's almost as if the entire committee was
composed of engineers living in a vacuum, and that nobody from the real world
had anything to say about it at all.

That's the same text as appeared in the spec I read.

Thanks for the discussion, and for refreshing my memory on it.

-larry

--
" All I ask of my body is that it carry around my head."
         - Thomas Alva Edison -
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|   //   Larry Phillips                                                 |
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