I've asked this unfruitfully before, but I'd thought I'd try again and include some of the information I have tracked down myself. Perhaps if no one knows the whole answer, they can at least piggyback some new information on top of what I have now. I have a Sony Vaio FX220 laptop. This machine is based on the Intel 815em chipset, which incorporates quite a few peripheral functions: notably, video, sound, and ethernet. XFree86 4.0.3 works no problem with the the stock i810 driver, though resolutions less than 1024x768 seemed to only be supported through centering. The laptop has a NTSC video out port. Under Windows, output is switched from the LCD to the TV-Out port via Fn-F8. This does not work under linux. Nor does Fn-F7 work to switch output to the RGB monitor output. Linux CAN detech these key combos through the ponypi device included in recent kernels (I'm using 4.4.9). Based on this and some other things I've read on the net, I'm guessing that responding to these keys is handled in software on this laptop, as opposed to being handle by the BIOS as in some other machines. The 815em's handling of video is a bit complex. The chipset supports output of digital video (DV) through a 12-bit bus. The digital video goes to an Intel 82807aa chip which either drives the LCD screen or passed the DV signals to a TV-encoder chip. The 82807 chip is controled through a 2 wire "GMBus", which appears to just be a particular implementation of an i2c bus. The TV-encoder chip is apparently controlled through one of the standard i2c busses of the chipset. Based on what I've read (mostly from Intel datasheets and programming manuals), the 82807 is pretty smart, and getting TV-out to work seems like it ought to take little more than sending a command on the GMBus to toggle between LCD and DV pass thru mode. Of course, their may be timing issues I haven't considered. I'm 90% sure the above is correct. If anyone knows any point where I am for sure wrong, please correct me. If anyone can elaborate on any of the above, I'd appreciate that too. In particular, if anyone has or can point me to info on the programming interface for the "GMBus", that would be very helpful. It'd also be great if someone happened to know the make and model of the TV-encoder chip in this laptop. I asked Sony more than two weeks ago, but they have not responded. Thanks in advance for any help you can provide. Jay
