13W3

A video connector that used to be common on Sun, SGI, and other high-end UNIX workstations. These days it's becoming pretty uncommon, as everyone is (thankfully} standardizing on the 15 pin VGA connector. All of Sun's current monitors ship with VGA plugs, requiring Sun to include adapters that let people connect these monitors to Sun workstations with Ultra Creator cards that still have the 13W3 connectors.

The 13W3 connector has three mini-coax connectors built in, which supposedly enhance the video signal path. Given that one can't tell the difference between a signal from a 15-pin VGA connector and a 13W3 connector, though, this seems superfluous.

Known widely as the video connector made popular by Sun Microsystems, the 13W3 had a lot going for it. It is very durable, and difficult to insert improperly because the durable coaxial connectors at both ends lined up the more delicate pins in the middle. The 13W3 came with a fairly full set of signals; Three sense pins, various pins for sync, and of course seperately shielded runs of coax for each color signal. This connector has gone out of common use with the proliferation of inexpensive multisync monitors using the HD15 connector most commonly associated with VGA video.

This monitor was the mainstay for video on Unix workstations until the early to mid 1990s, including systems from IBM, HP, Sun, and SGI.

ELECTRICAL CHARACTERISTICS

Video signals are 75 ohm, 0.7V p-p (peak to peak.) All other signals are TTL level, except sync which is 75 ohm, 2.5 to 5 V p-p.

PINOUT

Those signals whose name is shown in italics are often unused and may or may not be connected. Older, single-frequency monitors (generally, those which have only BNC connectors on them for video input) typically use seperate Horizontal and Vertical sync signals, and there are many cables which break a 13W3 out into five BNC connectors.

1. GND (Signal Ground)
2. VSYNC (Vertical Sync)
3. SENSE2 (Sense pin #2)
4. SENSEGND (Sense Ground)
5. CSYNC (Composite Sync)
6. HSYNC (Horizontal Sync)
7. GND (Signal Ground)
8. SENSE1 (Sense pin #1)
9. SENSE0 (Sense pin #0)
10. CGND (Composite Ground)

• R: Red Video
• G: Green/Gray Video (For 1bpp monochrome as well as grayscale displays)
• B: Blue Video

LAYOUT

         13W3, Female
_________________________________
\    __              __   __    /
 \  /R \  1 2 3 4 5 /G \ /B \  /
  \ \__/ 6 7 8 9 A  \__/ \__/ /
   \_________________________/

         13W3, Male
_________________________________
\    __   __              __    /
 \  /B \ /G \ 5 4 3 2 1  /R \  /
  \ \__/ \__/  A 9 8 7 6 \__/ /
   \_________________________/

A male 13W3 connector has female coaxial connections for video, and vice versa. The gender of the connector is determined by the classic pin connections, not the coax.

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References:

Webpage: Hans Leibbrandt, How to connect a SUN 20" Premium (Sony) GDM-20D10 monitor to a PC with Windows 95/98/NT. 28 January 2002. (http://home.iae.nl/users/leibbran/sunmon/sunmon.htm)

Sun Microsystems, 20-Inch Premium Color Monitor Guide. February 1994.