Text 61432, 143 rader
Skriven 2010-07-17 14:11:00 av ED VANCE (1:123/140)
     Kommentar till en text av JAMES BRADLEY
Ärende: Cables                1/5
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JB>-=> TOM WALKER wrote to JAMES BRADLEY <=-

JB> JB>I was under the impression that a "null modem" cable was
JB> JB>something like a de
JB> JB>short across the RTS/CTS pins, or there abouts. A "cross over" serial ca


JB> TW> NO Shorts Invloved. BUT three pairs are crossed over, Hense the neam
JB> TW> Crossover Cable whaic really what a Nul Model Cable is.
JB> TW> The paris that cross over are TXD/RXD, RTS/CTS, and DSR/DTR where as an
JB> TW> example the TXD pin wire on one end goes to the RXD pin on the other
JB> TW> end of the cable
JB> TW> This was origionaly used to connect two Teletype machines in a building
JB> TW> without using a modem enabiling the machines to talk to each other

JB>Years ago, I read about a D-sub serial "null-modem" plug, that was meant to
JB>just test the serial port. What it shorted, is *way* beyond my recollection
JB>but, just the other day I saw a serial "null-modem" wire that had two ends l
JB>(I can only suspect) is exactly like you describe. I might have adopted the
JB>ethernet "crossover" nomenclature in my imagination?

James,

I searched through the files that I have saved and found these.

I found these on my 486 DOS computer.

The first one I captured on 04/19/1991 .

The second one 12/24/2001 .

Hope they can help You.


QUICK GUIDE TO COMPUTER CABLES

     by Bill Becwar

LEGAL STUFF - This guide is as complete and accurate as I can make
it, however, I can't be responsible for errors, omissions, typing
mistakes, bad downloads, or your dog biting you.  I know that
somebody, somewhere is going to cross a wire.  Best advice if you
want to build one of these cables: Complete the wiring all in one
work session.  Then check the connections, preferably with an
ohmmeter.  Go away for a while and do something else, then return
and CHECK the connections again.  If you have any comments or find
any errors, leave E-Mail to William Becwar on EXEC-PC, the largest
and finest BBS in the country, (414) 789-4210, or on CompuServe
72060,251.  Good Luck!



POWER SUPPLY CONNECTORS -

     Typical Power Supply has 6 Connectors: 2 ea. - 6 pin for
Motherboard Power and 4 ea. - 4 pin for Disk Drive Power.


Motherboard Power Connectors
     P8                                 P9
    Pin    Signal                      Pin    Signal
-----------------------------      ---------------------------
     1  -  Power Good                   1  -  GND
     2  -  +5v  (or N.C.)               2  -  GND
     3  -  +12v                         3  -  -5v
     4  -  -12v                         4  -  +5v
     5  -  GND                          5  -  +5v
     6  -  GND                          6  -  +5v


Disk Drive Power Connectors  (4 - 4 pin)

    Pin    Signal
-----------------------------
     1  -  +12v
     2  -  GND
     3  -  GND
     4  -  +5v



.MOTHERBOARD CONNECTORS -

     Motherboards have various combinations of connectors depending
on design type and built-in facilities.  These will be found in a
typical clone.


Backup Battery Connector (AT only)

    Pin    Signal
-----------------------------
     1  -  Batt+
     2  -  [KEY]
     3  -  GND
     4  -  GND


LED Power and Key Lock (AT only)

    Pin    Signal
-----------------------------
     1  -  LED power
     2  -  GND
     3  -  GND
     4  -  Key Switch
     5  -  GND


Speaker Connector

    Pin    Signal
-----------------------------
     1  -  -Speaker
     2  -  [KEY]
     3  -  GND
     4  -  +Speaker +5v


Turbo Indicator Connector

     Used only on Turbo switchable machines.  Safest Connector on
the machines that have it; can't be connected backwards!

    Pin    Signal
-----------------------------
     1  -  +5v
     2  -  *HIGH SPEED
     3  -  +5v


.MOTHERBOARD I/O CARD EXPANSION SLOTS

     Not exactly for cabling, but a good reference anyway.

8-bit slots (PC/XT/AT)

COMPONENT SIDE                     NON-COMPONENT SIDE
>>> Continued to next message

 * SLMR 2.1a #T348 * Disappointed? Too bad!
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