Enforcing video output without monitor detection

fse · 10-09-2014, 08:53 PM

I tried to use a 27' iMac (Late 2009) as external monitor for a Windows 7 laptop using a Fujitsu Port Replicator (PR08). iMac supports a Mini-Displayport input with max. 2560x1440 pixels (in "Target Display Mode"), while PR08 provides a Displayport output (also with 2560x1440 pixels). I connected both with a MDP to DP cable. According to specs, it should work - but it doesn't.
Neither does Displaylink driver (latest version 7.7) detect iMac as monitor nor does iMac switch into "Target Display Mode" (via CMD-F2 shortkey). It seems, that each side requires the other side to do the first step! iMac only switch into monitor mode, if it detects a valid video signal. Displaylink provides only a video signal, if it detects a monitor.
My question: Can Displaylink drivers be forced to provide a video signal, even if no monitor is detected? It seems, that original Windows graphic drivers would support this, if my laptop would have a Displayport output.

Thanks.

10-09-2014, 08:53 PM	#1
fse Junior Member Join Date: Oct 2014 Posts: 2	Enforcing video output without monitor detection I tried to use a 27' iMac (Late 2009) as external monitor for a Windows 7 laptop using a Fujitsu Port Replicator (PR08). iMac supports a Mini-Displayport input with max. 2560x1440 pixels (in "Target Display Mode"), while PR08 provides a Displayport output (also with 2560x1440 pixels). I connected both with a MDP to DP cable. According to specs, it should work - but it doesn't. Neither does Displaylink driver (latest version 7.7) detect iMac as monitor nor does iMac switch into "Target Display Mode" (via CMD-F2 shortkey). It seems, that each side requires the other side to do the first step! iMac only switch into monitor mode, if it detects a valid video signal. Displaylink provides only a video signal, if it detects a monitor. My question: Can Displaylink drivers be forced to provide a video signal, even if no monitor is detected? It seems, that original Windows graphic drivers would support this, if my laptop would have a Displayport output. Thanks.