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Is HDMI -> DVI INcompatible?
From all my research it now appears that the promise by HDMI to be "fully backward compatible with DVI" is a broken promise! It appears that HDMI will NOT read the format of the Extended EDID table through the DVI ports pin 7 which carries "reply" data (DDC signal) as to the display device's format capabilities (eg 720 x 480 OR 1280 x 720 etc) which resides in the PROMS on the interface board of the DVI port in the display device, so the HDMI ICs dont see it (and it my case the HDMI AVR sender wont supply 720p or 1080i and are greyed out on the AVR's GUI).
The DVI extended data is in a format defined long ago by VESA and the HDMI seeks to read extended blocks of the EDID table in a more recent format defined for CE. Why couldnt the logic in the HDMI ICs ID the display device as having a DVI port and then read the VESA format???
Truly, there has been NO/INSUFFICIENT effort by HDMI LLC to provide Plug and Play Compatibility with the millions(?) of DVI ported devices out there that are still too good to scrap. An alternative would have been for HDMI standards to proivide a manual (user) override/intervention to force a chosen format to be sent from the HDMI source device and/or intermediatory device (eg AV Receivers), but me thinks, too much arrogance on the part of HDMI LLC has "blinded" them to the need for a failsafe option.
For those interested I will shortly post two postings which I have made to threads on another site about my recent experiences in this area using Yammie RXV2600 and 2700 AVRs into my 1 year old BenQ PE8700+ Front DLP (and into other simlilar DVI ported projectors) using HDMI->DVI cabling.
I hope for a robust discussion on this issue in general so that pressure can be put on HDMI LLC and manufacturers of new HDMI equipment; and I also look forward to someone having solved or come up with a "workaround" to this problem as it relates to my own equipment.
Greig
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