Photoshop to Cintiq

I have a CS5 Extended version 12.0 x64.

I have a 2017 iMac connected to a 22HD Cintiq.

When I open Photoshop, it opens on the iMac not the Cintiq.How can I get the app to open on the Cintiq?

One issue is that I can't seem to grab and drag the CS5 screen over to the Cintiq.

Thanks!