Arduino Decimilia Pinout

I just bought an Arduino Diecimila, which is pretty easy to figure out except one thing. There is a pin (near the “POWER” section on the dev. board) in between “RESET” and “5V” that says “3V3”. What is that for? I would like to think it’s a 3V regulated supply; that would be awesome for certain non-5V add-ons! Am I right, or just dreaming?

Its a 3.3v regulated supply but you only get it when using USB.
It comes from the USB chip.

Ok. Thanks! So, when you switch the power jumper over to USB, then it expects a 5V regulated supply coming in, correct?

Its a 3.3v regulated supply but you only get it when using USB.

Actually, as of the Diecimilla the USB chip is always powered, so it turns out the 3.3V supply is always available. See the discussion in this thread.

(I just confirmed this with a multimeter.)

–Phil.