Yep, what he said. Any Compaq server KVM should always respond to Print Screen to bring up the interface. From there, it's pretty easy to work with. The older ones used just a basic menu with single colors, the newer KVMs moved to a GUI looking popup and allowed mouse control too.

Some handy hints, those KVMs support chaining multiple ones togther. Designate one KVM the master where you will plug in the console port to. Then connect port 1 to the console port of the KVM you want to chain it to. You can do that on all 8 ports for a total of 64 systems. If it's not acting right, the firmware might not be in sync on all the KVMs. The firmware on the newer ones are upgradable via a download, however the old ones had physical rom chips that would need to be replaced.