Refresh Rate of Screen on G2?

[matalog]

What are the available Screen refresh rates on the G2?

I'm wondering if it will be possible for the device to do something like a visual serial transmission via the screen - flashing black/white square to be read with a phototransistor.

Well, I know it will be possible to do, but I'd need to know the refreshrate of the screen to know the speed limit for such a transmission.

[TheLastMillennial]

Holding on and shift while pressing +or - will adjust the refresh rate. It goes from 55hz to 125hz if I remember correctly.