Analog read.

No problem now but for those that didn't know, do not expect an arduino out right out of the protective wrapper to be "Default". I was trying this simple code and the readings were not changing much.

Adding analogReference(DEFAULT);
made the difference.

Very important to know if you use analog inputs.
I was just checking out something before I use it in other code.

int potin = A1;
int potread;
int mappedpot;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  analogReference(DEFAULT);
}

void loop() {
  // put your main code here, to run repeatedly:
  potread = analogRead (potin);
  mappedpot = map(potread, 0, 1023, 100, 1);
  Serial.print(potread);
  Serial.print(" ");
  Serial.println(mappedpot);

}

That is the first time I've heard anyone claim that their Arduino was not using the DEFAULT analog reference on power up or reset.

Yes, that is interesting. I have seen posts about all analog pins broken like this one Broken Analog Inputs? (all of em are at 1023) - Installation & Troubleshooting - Arduino Forum and now I'm wondering about this.

Could some vendor be shipping with a bad bootloader? Try burning a fresh bootloader.

?? Could have been tested and loaded with code?? I don't remember who I got it from. I have bunches of them from various places.

Works fine without having to set to default.