What kind of video processor is provided by the MacBook Air? What is the maximum resolution it can support on an external display?

The original MacBook Air has an "integrated" Intel GMA X3100 video processor with "144 MB of DDR2 SDRAM shared with main memory." It is capable of simultaneously supporting 1920x1200 on an external display as well as the internal 1280x800 display.

The "Late 2008/NVIDIA" and "Mid-2009" models have a NVIDIA GeForce 9400M video processor with "256 MB of DDR3 SDRAM shared with main memory." These models are capable of supporting 2560x1600 on an external display as well as the internal 1280x800 display.

What is a "micro-DVI" port? How is it different from DVI and mini-DVI?

On basic terms, "micro-DVI" is even smaller than mini-DVI, which in turn, is smaller than the full-sized DVI. Even though micro-DVI is smaller than the mini-DVI provided by the "White and Black" MacBook models, it still is capable of supporting 1920x1200 on an external display in dual display or mirroring mode.

Diagram Credit: Apple, Inc.

For complete technical details of the micro-DVI port -- including signals and pin assignment -- please refer to the Video Developer Note from Apple.

Please note that micro-DVI is provided by the original MacBook Air model. Subsequently released models use a different standard called "Mini DisplayPort".

Also see: What is "Mini DisplayPort"? Is it an industry-standard? How is it different from or better than Mini-DVI and Micro-DVI?

What ports are provided by the MacBook Air?

The MacBook Air has a remarkable dearth of ports. On the right it has a small "trapdoor" that drops down to expose a standard speaker/headphone jack, a single USB port, and either a micro-DVI or Mini DisplayPort connector (note that this door actually drops "down" from the underside of the computer rather than merely "flipping out" the side). On the left it has a MagSafe power connector -- but turned at a 90-degree angle to conserve space. That's it.

Those who need a greater number or variety of ports onboard -- more USB ports (hubs are available) or Firewire ports, for example -- probably would be better served by a MacBook or MacBook Pro.