FireWire to Thunderbolt Adapter I would like to connect a third display to my Mac Mini Late 2012. Since I'm already using the HDMI and Thunderbolt I'll have to use something else. I read in a couple of forums that you can connect another monitor using some kind of external graphics card and a USB slot.
Now, I thought about using the FireWire slot. I found an Apple adapter the other way around but is there an adapter with Thunderbolt input that I can plug into the FireWire?

OR:

I saw that the new Mac Mini has a second Thunderbolt slot, instead of the FireWire. Is there a way to modify my Mac Mini to make it have 2 Thunderbolts as well?

Thanks in advance
You can use a DisplayLink adapter to connect another monitor via USB; see here for the varieties available.

The Apple Thunderbolt to FireWire adapter only works in that direction; it will not convert FireWire to Thunderbolt. 

You cannot modify your mini to have another Thunderbolt port. You can get a Thunderbolt dock that will give you a monitor port and another Thunderbolt port on the dock, which might also work, but is more expensive than DisplayLink (make sure to get a dock that will "daisy-chain".