how to i use my Imac (minidisplayport) as a monitor for my macbook pro (thunderbolt)

Hello twazzack2

All you would need is to have a Mini DisplayPort to Mini DisplayPort cable to setup the Target Display mode for your iMac. Below is an article that will assist with getting that setup for you.

Target Display Mode: Frequently Asked Questions (FAQ)

http://support.apple.com/kb/HT3924

Target Display mode Requirements:

What are the requirements for TDM?

• A Mac notenook or desktop with a Mini DisplayPort or ThunderBolt connection
• A ThunderBolt or Mini DisplayPort cable
• A supported iMac with OS X 10.6.1 or later. The table below shows iMac computers that support TDM, the required cables, and the port of the computer to which you are connecting the iMac.

iMac Model	Cable Supported	Port on Target Computer
iMac (27-inch Late 2009)	Mini DisplayPort to Mini DisplayPort	Mini DisplayPort or Thunderbolt
iMac (27-inch Mid 2010)	Mini DisplayPort to Mini DisplayPort	Mini DisplayPort or Thunderbolt
iMac (21.5-inch, Mid 2011)	Thunderbolt to Thunderbolt	Thunderbolt
iMac (27-inch, Mid 2011)	Thunderbolt to Thunderbolt	Thunderbolt
iMac (21.5-inch, Late 2012)	Thunderbolt to Thunderbolt	Thunderbolt
iMac (27-inch, Late 2012)	Thunderbolt to Thunderbolt	Thunderbolt

1. How do I enable TDM?
   • Make sure both computers are turned on and awake.
   • Connect a male-to-male Mini DisplayPort or ThunderBolt cable to each computer.
   • Press Command-F2 on the keyboard of the iMac being used as a display to enable TDM.
2. How do I exit TDM?
   To leave TDM, press Command-F2 on the keyboard of the iMac that is in TDM. You can also exit TDM if you shutdown or sleep either computer or detach the cable.

Thanks for using Apple Support Communities.

Regards,

-Norm G.