Ca peut t aider ...
The you would need a Mini-Displayport to DVI adapter. You plug the Mini-Dispalyport end into one of your Thunderbolt ports.
The 3 cords from the Monitor are most likely:
1. A USB cord to connect to one of your MacMini's USB ports, this would allow the USB ports on the back of the monitor to be used (they will be only USB2 though). It will also facilitate the use of the keyboard keys for controlling the monitor's brightness.

or

Illaass is right about the Firewire extension. You would need a Thunderbolt to Firewire adapter to connect that and then the connections on the monitor would only be Firewire 400.
2. The DVI connects to the DVI end of the adaptor.
3. Then there should be a power cord that attaches to a AC power brick.
Lien : https://discussions.apple.com/thread/7394652