This is a rehash of a thread on the developer mailing list from September 2011 and I wonder how things have moved on since then.
My computer is an HP t5745 which has two video outputs, shown in the GNU/Linux ‘lspci’ output as:
00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 09)
00:02.1 Display controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 09)
My display is connected to the second device but Haiku displays to the first, which is a lower-resolution analogue output and in fact it won’t go beyond 1024x768. How can Haiku be made to display to the second ?
That’s not two display adaptors, that’s one display adaptor with multiple outputs. The extra PCI device is a fiction used to keep older versions of Windows happy with the idea of multiple screens when only a single video card is actually present.
Most likely Haiku simply doesn’t support your Intel chipset, there are several variants of that particular chip and Haiku only supports some of them, leaving the rest in VESA mode. Without support for the chipset there’s little chance that additional outputs or higher resolutions will work. You could create a ticket asking for such support, though there’s no certainty anyone will work on it. If you do, probably you should include the results of lspci -n which shows the exact numeric ID of the adaptor instead of the friendly name from your output above.