[rescue] SOG converter

[Jonathan C. Patschke]

On Sun, 20 Apr 2003, Curtis H. Wilbar Jr. wrote:

> If this is for an SGI, unless I read the pinouts incorrectly, SGI does
> provide a composite sync separately from the sync on green... they
> use a different pin in the 13W3 than Sun does though.

That is correct, which is why all the fools on eBay that claim they have
an "SGI/SUN PC MONTIOR ADAPTAR L@@@K!" are full of it[0].  You can do one
or the other, but not both.  Specifically, SGI uses Sun's CSYNC pin to
do some sort of monitor ID.  Thus, connecting a monitor expecting CSYNC
there to an SGI can possibly damage the monitor, if it doesn't have
protection against bogus sync signals.

> Maybe not all SGI's provide this signal though ?

My Octane/SI, O2, and Indigo2/SI do.  The O2 does PC-style sync as well
as SOG.

> Anyone have any real world experience with this ?

Well, if your monitor is smart enough to interpret SoG, it's probably
smart enough to ignore the CSYNC pin.  However, mine isn't.  So, when I
connect it to the O2, I get a beautiful screen with the green gun -way-
too warm (because it found sync on CSYNC, and is reading the green pin
at face value).  When I connect it to the Octane or Indigo2, it spazzes
out because it's getting a bogus sync signal that it doesn't know how to
ignore.

I solved this by using a pair of 13w3<->5BNC adapter cables and three BNC
T-connectors in the case of the Octane and Indigo2, and a 13w3<->5BNC
a HD15<->5BNC adapter, and three BNC T-connectors in the case of the O2.


[0] People on eBay without clue!  Say it ain't so!
-- 
Jonathan Patschke *) "who has been feeding my cats crack again??  they
Thorndale, TX     (*  were doing chuck norris shit all over the apartment
                  *)  this morning"                     --alex j avriette