[RndTbl] Query your CRT Monitor EDID using ddc-control - but not yer LCD

[John D]

Hello

Further to a question at MUUG Nov. RoundTable, about the nature of the data 
exchanged when we (or xorgconfig does a) "probe for type of monitor"

VESA-compliant video cards (post'94) have a function to ask an attached 
monitor its EDID info.

This handy VESA function is nicely explained by:
	http://en.wikipedia.org/wiki/Extended_display_identification_data

Unfortunately, modern flat displays and TVs are not well represented under 
EDID paradigms.

EDID data for a monitor is programmed into a serial (usu.i2c friendly) PROM at 
manufacture.  This self-descriptor keeps enough data to be capable of being 
"verbose" when queried; e.g: Mfg ID, Prod ID, SerNum, WkMfg, YrMfg, HSync, 
VSync, Resolution (EDID "thinks" this geometry must be multiple-of-8)

However, the recent Linux version of _ddc-control_ includes a separate 
XML-formatted db, which has been updated as recently as 2006-10.

Haven't read inside latest _ddc-control_:
	http://sourceforge.net/project/showfiles.php?group_id=117933
-but I suspect its useage is de-volving (at least for LCD and 'wide' displays) 
to a terse query from monitor, getting just the Maker, Model, and then using 
those to do a lookup in the XML-db.

Another Linux tool _read-edid_ also reads info from monitor:
	http://freshmeat.net/projects/read-edid/

Assembler and x86 machine language fans will enjoy this 2003-04 kernel snippet-
	http://lwn.net/Articles/27597/

smiles,
John D