I uploaded the Examples > Basics > Read Analog Serial to an Arduino Zero. However, when I try to open the Serial Monitor this error "Error opening serial port 'COM12'. (Port busy)" pops up. What needs to be done to eliminate this error. The IDE did say "Done Uploading" indicating the example was successfully compiled and uploaded.
Previously I tried the Examples > Basics > Blink. This example looks like it is working. However the messages displayed while uploading the example were printed in red. I am using Arduino IDE 1.7.6. In the past red meant an error. Has there been in change in the color code used to display messages.
If you are using windows, go to device manager (with the arduino connected to the pc) and look at the serial port created for the arduino. In the advanced properties you can assign a comport for the arduino. The USB serial devices often do not get cleared from the comport list indicate the comport is in use when it isn't.
Your advice is on the mark. Before reading your reply I restarted my computer and this eliminated my COM Port busy problem. Once the COM Port busy problem was eliminated the Arduino Serial Monitor displayed the analog voltage readings. I book marked the Web Page you provided for future use.
I see now I should have used the Arduino Zero category for my question.