My friend bought an iMac that has only Thunderbolt and USB2 connections for an external backup up drive. I'm supposed to

[jdc]

Dude, you gotta try and stop making everything so complicated?

The last 4 posts are dead on. USB 1, 2 and 3 are ll backward compatible

Just get a simple USB drive -- screw firewire, forget TBolt. You dont need to look at the iMac again. Its got at least USB 2, which is more than fine for any use.

this one at staples is perfect. 1TB, $70. Plug in, start Time Machine, forget about it.

http://www.staples.com/WD-My-Passport-fo...uct_984730&cmArea=CIRCULAR