DVI-D to VGA adapter
2014-07
ko4evneg
I know that DVI-D is digital only and can not be transformed to VGA with passive adapter. I want to know where this adapters are used? Or is it just a marketing trick?
Example of this adapter here: http://www.amazon.com/CablesToBuy-DVI-D-Male-Female-Adapter/dp/B001CHQ52W/ref=pd_bxgy_pc_img_z/183-0695115-2473620
nitro2k01
One potential intended use would be to screw two of these adapters to the each end of a VGA cable to use it as a DVI-D cable, depending on how things are connected inside. This makes little sense as two of these adapters would cost about the same as a cheap DVI cable, not to mention that it would have worse electrical characteristics. Then again, that's nothing more than a guess.
This adapter can not work as a passive DVI-I -> VGA adapter however, so the intended use cannot be that. The adapter is missing the 4 pins around the grounding pin on the side. This is where the analog red, green, blue and horizontal sync signals are transmitted. Without those pins, no DVI-A signalling is possible. The pinout is explained on Wikipedia or as a close-up here.
Joel Coehoorn
I suspect the answer to this is "no", but here goes:
I have a monitor with inputs for DVI and VGA. I want to be able to share this display with two computers (one at a time, of course) that both have VGA only. I also have a DVI->VGA dongle that came with a video card that's in a different computer.
Can I connect this dongle directly to the DVI port on the monitor so that I can connect both VGA computers? I'd rather not resort to a kvm.
David Spillett
No, you'll need to use the KVM option or buy a couple of VGA extension cables and manually switch between the two (bring the two monitor ends of the extensions and the PC end of the monitor's table up to you test and hold them there with something like http://lifehacker.com/5499838/binder-clips-as-cable-catchers-redux%5D and just plug the monitor one into the right extension when you need to). You might find a cheap 2-machine KVM with the required cables doesn't cost much more than a couple of plain VGA extension cables though.
A DVI->VGA "converter" doesn't actually convert any signals at all. Most DVI ports on graphics cards also carry the analog RGB signals needed by a VGA monitor along side the digital signal lines (see http://en.wikipedia.org/wiki/Digital_Visual_Interface for relevant pinout diagrams) and all the adaptor does is connect these pins to the right pins of the VGA port. So unless your monitor can accept the reverse (analog signals through its DVI input), which I doubt many (if any) do, this does not work the other way around.
Tom Wijsman
Nope. The DVI-->VGA dongle is actually "DVI-I" to VGA. The "I" representing that the DVI port has the analog signals needed to convert to analog VGA.
Since the Monitor doesn't produce a signal (analog or otherwise) they only have DVI-D ports on them ("D" being 'digital-only'), so you won't even be able to plug the dongle into the port (the spade is the wrong size, and there will be 4 extra pins on the dongle (these are the analog signal pins).