Hey Jason,
The first step in midi control is getting a midi controller. There are several possibilities. A simple musical keyboard from wal-mart usually has midi capabilities. You can make this a simple or as complicated as you want. If you want more options let me know and I'll give you some more.
From here on out, every time I say controller i'm talking about the midi controller. Every time I say console, i'm talking about the operator 192.
Okay as far as setting up the console to accept the commands first you got to figure out what channel your controller is using. I believe midi has 16 different channels. Most controllers transmit on channel one. Once you have the figured out then you can set the console to the same channel.
1) Press and hold down the MIDI BUTTON for 2 seconds or until the LCD displays "In:XX" (XX is a number that represents the channel it is currently set to).
2) Use the UP/DOWN BANK buttons to set the channel to whatever your controller transmits on.
3) Finally, hold down the MIDI BUTTON again until all LED's flash three times.
Now, here is how you use it. The way midi works is by sending out a MIDI note. The number of this note triggers certain aspects of the DMX Operator. Check the manual on the controller to see which keys/buttons send which number note. In the console manual it says that if the console receives a signal from any note between 0-11 it will turn on/off chase 1-12. This means that if you hit the button on your controller that corresponds with the midi note #0 then that will turn on chase 1 on the console. All the rest of the features work this way with different note for the different features, there is a table in the consoles manual that shows which notes do what.
I hope all that makes sense! If not, just let me know and I'll elaborate.
Oh, of course make sure that you have a MIDI cable connecting the controller and the console. Out from the controller in to the console.
Hope the helps!
-Tyler Herron