Programming with Mac OSX 10.4

My operating system: OS X 10.4.2 Kind of board: Arduino UNO I use the Blink file: I change the delay of the loop (ex.: 5000 instead 1000), then I upload the change, but the messages displayed is: avrdude: stk500_recv(): programmer is not responding The board is connected to /dev/tyy/usbmodem3511. I used also /dev/tyy/SerialPort-1 but is the same.

Did you select Arduino UNO under Tools->Boards?