Apple HD Cinema Display 30

This is great, thank you. The Monoprice website would not accept my payment so I went with Amazon. I'll report back and thanks again.

the device you posted is for Dual -Link DVI, required for displays over 1920 wide. it is needed for the 30-in, but is overkill for the 23-in.

But will work, even in overkill-mode?

more than twice the price, but should work fine.

Doug and Grant, thanks again for the help. Overkill yes, but it works a charm.

This diagram (lifted from Wikipedia) showing the signals helps me understand:

(drag and drop on Preview to see larger)

Single-Link DVI is good for displays up to 1920 wide. It can have the center six pins (medium blue in the diagram) de-populated. Single-Link DVI cables do not connect the center six conductors end-to-end, whether they have the pins or not.

To go wider than 1920 wide, you need more data. The single-link DVI is already switching pretty fast, so they opted to add another three signals (six conductors) to supply the additional information. This makes converting Dual-Link DVI to and from anything else a nightmare.

Both HDMI and DisplayPort opted instead to try to switch the signals faster on the same number of conductors, which is ultimately easier to convert.

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The other wonky thing about the DVI connector is that the computer port supplies a VGA signal DIRECTLY -- in the blade at one end, the four pins around it, and one more Sync from the top row of the grid salmon-pink on the diagram). to get VGA, one uses a thing that should be called an Extractor rather than a Converter.

You can also see illustrated that once you plug in an "ordinary" DVI cable, the VGA signals will be left unconnected, and un-available at the other end of the DVI cable. This illustrates why it is generally essential to make the adaptation in at most ONE adapter -- because the wealth of options may only be available directly on the computer port, not at the far end of a connected cable.