arduino uno r3 doesn't upload first sketch

Got my first arduino uno today, put an LED into 13 and GRND and connected it to my Linux OpenSuse computer. As soon as the board was connected to the computer began to blink. The LED went on and off in a ca. 1 second rhythm. I did not upload any sketch yet.
Then I wrote my own sketch:

const int LED = 13;
void setup()
{
pinMode(LED, OUTPUT);
}
void loop()
{
digitalWrite(LED, HIGH);
delay(3000);
digitalWrite(LED, LOW);
delay(2000);
}

The system didn't manage to upload this to the board. Instead I got the following error report:

This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.
Arduino: 1.0.6 (Linux), Board: "Arduino Uno"
/usr/bin/avr-ld: warning: -z relro ignored.
Binäre Sketchgröße: 1.058 Bytes (von einem Maximum von 32.256 Bytes)
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x00
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x00

What went wrong? Can anybody help?

What port is created in /dev/ when you connect the board and do you have rights to write to it?

The port was /dev/tt50. I changed to /dev/ttyACM0 now it works!

Thanks for the tip.