Is Thunderbolt backwards-compatible with mini-DP for both input and output?

How compatible or not is the new Thunderbolt connection?

If I have a MacBook Air with Thunderbolt, can I use my existing mini-video cable to connect it to a VGA overhead projector?

If I buy a new Cinema Display with Thunderbolt, can I connect my existing Mac Pro to it?

Are there special cables, convertors needed, or are there any fundamental incompatibilities?

Solution 1:

Your existing Mini DisplayPort cable (VGA adaptor, etc.) should allow your Thunderbolt equipped MacBook Air to connect to a projector (assuming it worked previously with a Mini DisplayPort output) but, as with all things presentation, you'll want to test the setup in advance if possible.

According to Apple's specs, the Thunderbolt Display requires a:

Thunderbolt-enabled Mac computer, including MacBook Air, MacBook Pro, Mac mini, and iMac

Your existing Mac Pro can't use the monitor.

Solution 2:

• A Projector connected to a Mini DisplayPort adapter, connected to the Thunderbolt port of a MacBook Air should work as expected.

• I don't think that the Mac Pro can currently (officially) drive a Thunderbolt Cinema Display.

You may find this article informative.