Questions about detuning...

[Remedial]

Okay, some from my reading of the manual and it appears to me that the detune knob is the only option for some form of fine detuning. Now, is that knob gradated in cents? There's no mention of this in the manual. Next, although the detune knob can be used in reference to oscillator 3, said oscillator also has a detune menu in the oscillator menu options. Now, does this mean that, when using the detune knob on oscillator 3, you are detuning it in reference to oscillator 2 but when you use the menu screen you are detuning in reference to oscillator 1 (which the manual does say)? Now, also, because the detune knob does not present negative values, I'm guessing there's no negative detuning. Or, is it one of those knobs where at 64 and over you cross over to positive detuning but everything beneath that is negative? Please help me with this. The manual is a little confusing with these matters and I would love some clarification. Thanks beforehand.