Increase Undo/Redo History

I thought I read about being able to increase the history, but I cant find it when I google it. So is there way to do this, if so how?

If it helps I an running 2.63

File / User Preferences / Editing, increase the undo steps


Thank you, thought I had looked there, guess I over looked it. What does the memory limit due, right now mine is set to 0. Not sure if the 0 signifies no memroy limit, or unlimited memory limit.

Memory limit can be set to be the maximum memory used for undos in case you have a limited memory. A value of 0 means there is no memory limit.

k, thank you