In article ,
says...
On Sat, 17 Nov 2007 14:36:30 -0800 (PST), webpa put
finger to keyboard and composed:

I give up: How does a Sony (FX-140) notebook recognize the presence of
an external (VGA/SVGA) monitor? Many Google hits on the topic provide
monitor ID bit identifications...and variations thereon. But NONE of
them seem to work. That is: Grounding the indicated pins, in all
possible combinations, does not cue the computer that a monitor is
connected. It cannot be that the FX-140 requires active communication
with a monitor, because the computer recognizes ANY connected monitor
(have tried 5) whether they are powered or not.

Any hints? Diodes between pins...resistors...holy water?

If the notebook recognises that a monitor is present but cannot
identify its capabilities, then it is probably sensing the 75 ohm RGB
terminations. If the notebook can ID the model, make, and refresh
rates, then it is reading the monitor's EDID EEPROM. Note that it is
the notebook's graphics subsystem which provides the power for the
monitor's EEPROM, not the monitor.

See the DDC info he
http://pinouts.ru/Video/VGA15_pinout.shtml

The EDID data block will appear in your registry.

I have also managed to read a monitor's EDID EEPROM using my device
programmer. I made a VGA DB15-to-DIP8 adapter cable and told the
programmer that it was connected to an Atmel AT24C21 EEPROM which has
a "DDC1/ DDC2 Interface Compliant for Monitor Identification".

http://www.atmel.com/dyn/resources/p...ts/doc0405.pdf

- Franc Zabkar

OK, that sounds kinda fun. I'm going to look into that if my programmer
has the ability to program that Eeprom...

Thanks for the info Franc,

- Tim -
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