How to force DVI output in Linux

[NightSprinter]

Question in regards to the Linux version: how do I actually get the card to output to just the DVI port?  I've also been using my Startech PEXHDCAP as a way to test compatibility with games that use refresh rates between 50 and 60Hz for capture, but want to sometimes output a game over the DVI-D port to see if newer drivers have improved compatibility (as some I know do use it and its Micomsoft counterpart to capture video from arcade PCBs).  Just using -connector DVI-0 just causes output  to my NEC monitor, which makes it show at the wrong resolution.

[Calamity]

Question in regards to the Linux version: how do I actually get the card to output to just the DVI port?

I haven't managed to get dual head setups working properly with Groovy yet. I guess part of the solution must involve compiling MAME with the SDL 2 option, because SDL 1.2 doesn't have support for multiple screens, but tried that and still didn't work. The other part must be configuring X properly. Some people just claim it should work by enabling both screens in xorg.conf but I don't see anyone out there proving they have done it, and everything I tried didn't work either (just to clarify I don't mean the typical dual head desktop but instead launching MAME to either head by means of a command line option and setting the right resolution there automatically, just as we do in Windows: pure full screen without the clone mode crap). In theory GM is ready for this (the -connector option) by sending the right connector name to xrandr, but something is missing to get this working properly.

So... if you want to enable the DVI output, you need to force it from the boot kernel line, then it should work fine for the rest.