Forcing a resolution on a computer without monitor

Question

I have this computer running an embedded version of Windows 7 and it does not have any monitor attached. It is only accessed with VNC (alternatice for RDP) so a monitor is not needed. The problem is that I really need it to display 1680*1050 and that is possible when I hook up a monitor, but when I take away the monitor it only has a few resolutions left on which it can run. None of them is 1650*1080.

So is there a way to "force" the right resolution? I know there are other questions like this, but they did not have the right answer for me. Switching to RDP is not an option BTW.

I am also quite curious as to why it can only display the right resolution on a monitor. If it is at all possible to give me some insight into this I would appreciate that.

Solution

So this is how I solved my problem: There is this thing called a "Dummy plug". Basically it is just a VGA cable with one of the RGB signal lines connected to GND through a 50-150 Ohm resistor. The computer will then beleive that a monitor is attached, but it can't detect the resolutions it can display so it displays all resolutions.

Comments

[ganesh]

I had (well have) a similar problem and I have no found a decent solution yet. Best workarounds I have atm are: 1) Use VGA and short circuit the 'monitor detected' pin, then list all modi and set one. (Ugly, but also often usedto get dedicated CUDA cards to work without attaching a monitor). Or you can attach a monitor (no need to actually look at it). Atm I use the last, but it is large, bulky and not suited to embedded solutions. It will be interesting to see what answer people come up with.

[larzz11]

Hm I would not necessarily be against the first option.... If you are sure that this works, you should add it as answer....

[larzz11]

@Hennes I cannot find any information on the method you suggested. Can you maybe give me a link or something? Maybe I am googling for the wrong things.

[ganesh]

overclock.net/t/384733/the-30-second-dummy-plug

[larzz11]

Thank you for your answer, but as the name of the checkbox suggests: that only works when a monitor is attached.

[Chris]

With a second monitor or when you're in the options panel?

[larzz11]

In any case it only works when a monitor is attached. Setting the resolution and the removing the monitor does work, but only till the PC reboots

[Arvo Bowen]

As a side note: headlessghost.com