On Mon, Sep 01, 2003 at 02:53:25PM -0400, Randy Kramer wrote: > On Monday 01 September 2003 10:50 am, Bonny wrote: > > What is the meaning of the "syncongreen" option which can be inserted > > into a "Monitor Section"? > > My first smart-ass answer is that if you need to ask, you don't need to know. > ;-) Correct. :-) > What I think I know: > > Some monitors have 3 or 4 BNC connectors instead of the 15 pin DIN connector > typical of modern (S)VGA monitors. When there are 4 BNC connectors, the sync > signal must be sent on one of those by itself. If there are only 3, the sync > signal must be combined with one of the color signals, usually green (I > think). > > What I don't know: > > In the typical 15 pin DIN connection, I don't know if sync is a separate pin > or not. > > I don't know if some monitors (15 pin or BNC) require the sync on some color > other than green. VGA connectors (DB15HD) carry the horizontal and vertical sync on separate pins, among other things because the polarity of those signals tells the monitor something (though I don't remember what). Monitors with BNC connectors may have 3, 4, or 5. If they have 5, the sync is separate: RGBHV. If they have 4, it's combined: RGBS. If they have three, it's composite, usually written RGsB, or sync-on-green. It's also worth noting that most large-screen monitors with *only* BNC connectors are fixed-frequency; while you can run them from X slightly more conveniently than from Windows, you *can't* see anything in text mode, unless you configure your machine to boot to the frame buffer... and you *still* won't be able to see anything in the BIOS. I've never seen a monitor where the composite sync was on any other color than green. Cheers, -- jra -- Jay R. Ashworth jra@xxxxxxxxxxx Member of the Technical Staff Baylink RFC 2100 The Suncoast Freenet The Things I Think Tampa Bay, Florida http://baylink.pitas.com +1 727 647 1274 OS X: Because making Unix user-friendly was easier than debugging Windows -- Simon Slavin, on a.f.c _______________________________________________ XFree86 mailing list XFree86@xxxxxxxxxxx http://XFree86.Org/mailman/listinfo/xfree86
