I2C testing on Due

Hi folks, I am trying my first test with I2C on the Due. Just trying to use Wire to write a test message over and over as a master. I just have one Due that I am monitoring with an analyzer. I'm looking at this example: http://arduino.cc/en/Tutorial/MasterWriter

Problem: At this point the SCL1 and SDA1 pins remain continuously in a high impedance state. Meanwhile pins 20 and 21 appear to be pulled up to 3.3V as expected.

First, is it correct that the Due starts executing automatically after download?
Is there evidence on the Due that it is executing LED?)
Is it correct that I use the SCL1 and SDA1 pins near the AREF pin?
Don't I need to use pullups to get these lines to work properly?
Which set of pins are activated by Wire on the Due? Is it both sets (one a copy of the other) or can you choose either/or?


This thread should answer all your questions:

Awesome. Thanks.