[rescue] Re: SGI Video - PC Monitor (*)

[Eric Webb]

On Thursday 28 March 2002 10:31 pm, you wrote:
>
> > However, my 19" SVGA won't display anything.  It's reporting 0khz
> > horizontal and 72.2khz vertical.  This tells me that the hsync line is
> > either grounded or not connected and the vsync line probably is
> > connected.
>
> Actually, it's more complicated than that.  All syncing is done over the
> green line on an SGI.  However, the SGI has either grounded the hsync pin,
> or it sending monitor ID requests over what would be the hsync pin.
>
> The sync-binding happens on the SGI gfx card, so it's not that the cable
> is wired incorrectly or that the cable is supposed to break those signals
> off.
[snip]
> If it's getting vsync, it does SOG, as the vsync is sent on the green pin.
> Hsync is send on there also, but if the hsync pin looks weird, your
> monitor might be ignoring the hysnc component of the green pin.

This is what I originally thought, but then I saw the email that I replied to 
in my original message (written by Michiel) where he saw all three sync 
signals on the SGI 13W3 connector.  So, I'm thinking that maybe the 
13W3->HD15 is unintentionally confusing my tube by passing too much or only 
part of the sync lines.

I think crafting a "breakout" cable is a good idea, I just gotta find the 
13W3 connectors.  (Or, I guess I could do this on the HD15 side, since those 
are easier to come by.)

-E.