what are those symbols on the arduino schematic?

found those symbols (the first 2) what are they, and how can i find them on OrCAD?

about the third.... i found a few of those "floating" circuits that appear in the arduino rev 3 schematic i can see the net (i think this is a net) number 8 and 4, but not sure where they are connected to....?

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this is the schematic: https://dl.dropboxusercontent.com/u/38094905/Arduino_Uno_Rev3-schematic.pdf

Top P MOS FET Middle Polarized capacitor Bottom capacitor

I don't use Orcad but if they are not available, I am sure you can make then using the software.

The polarized capacitor symbol is the European version - the American version is what you're probably used to seeing.

Re the "4" and "8" - they should tell you where it goes, but looking at the schematic, I can't work it out either. It's 0.1uf, so it's probably a bypass cap for... something...

I think that’s just the implicit power/ground pin count.

Top symbol is the P-fet that disconnects the USB supply when Arduino is powered externally with more than 6.6volt on Vin, or with more than 7.3volt on the DC jack. RN1a/RN1B/Lm458 is the 6.6volt detector.

PC1 is the Vin electrolytic buffer cap.

4 and 8 are the supply pins of the LM458 with a local decoupling cap. Leo..

“floating” circuits

In Eagle, nets with the same name are all connected, whether or not there are lines drawn.
In this case you have the cap, and some IC pins connected to +5V and GND.