Question: how to connect a second monitor to a mac pro?
Answer: The MacBook Air requires a mini DisplayPort to HDMI adapter. On an older MacBook Pro, you have two options: HDMI or Mini DisplayPort/Thunderbolt. As mentioned earlier, if your monitor has DVI, you can get Apple's Mini DisplayPort to DVI adapter. If your monitor has HDMI, you can plug an HDMI cable in directly.