Need Sun RJ-45 console cable

Tue Nov 26 15:05:55 PST 2002

Jim Hickstein writes:
>--On Tuesday, November 26, 2002 10:28:55 -0800 Chuck Yerkes 
><chuck+baylisa at snew.com> wrote:
>
>> It's a cisco pinned connector.  Easy enough.
>
>For such as we, yes.  That did the trick, anyway.  Thanks!
>
>Without a working knowledge of RS-232 and a handy supply of Cisco 
>part-number adapters (if not Sun), my supplicant would have and remained 
>screwed.  He knows this, now.
>
>> I took a T3 disk array with a zero doc RJ-11(!) console.  Crimped
>> wires into a plug and shoved them into pins 2 and 3 of a nearby
>> serial port to get it to work.  I had always wondered why Sun DB-25
>> serial ports were female.  Now I know.  Try it and frighten your
>> co-workers.
>
>They were female because they decided against following the standard, which 
>is quite clear: DTEs are MALE, DCEs female.  Only DEC, IBM, and HP, to my 
>knowledge, ever actually adhered to this.  Shame on everyone else.

For those who don't remember the RS-232 acronyms, here's a translation
of what he just said...
    DTE = Data Terminal Equipment (e.g. a terminal, teletype, etc.)
    DCE = Data Communciations Equipment (e.g. modem, etc.)

It's true that almost all terminal manufacturers failed to follow the
standard, and produced terminals with female connectors - except DEC,
IBM, and HP (DEC I knew; I never worked with IBM or HP terminals but
I'll take your word for it).

The trouble came when they started making computer workstations that
can serve either as a terminal or as something you plug a terminal
into.

IBM stuck with the DTE interpretation for their PC's (and hence modern
PC's), as there wasn't much call for hooking a terminal up to an MSDOS
box.  However I would argue that Sun was justified in using female
ports.  They probably figured they were DCE's, because you could hook
a terminal up to a Sun workstation.  This was done to allow many
people to log in to the Sun at once, and/or for a serial console for
those who didn't need (think server) or couldn't afford the expensive
optional video hardware.  Anyway, Suns were suppposed to be networked
(remember, "SUN" was named for "Stanford University Network") so why
plug a modem into one?

Quaere: what gender DB-25's did Macs have?  I think the current Macs
don't have them at all, but I seem to recall the early ones did.  And
I think it was female, in which case shame on them, but I'm not sure.

--Bill.

-- 
William R Ward            bill at wards.net          http://www.wards.net/~bill/
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