Can't see /dev/tty.usbmodem* on my mac

Hi All,

I am a newbie to Arduino and connected my Uno board with my mac to test the "Blink" program.
I have connected the Uno board with the standard USB A/B cable. I see the power light on the board
The serial ports that it lists are as --
/dev/tty.Bluetooth-Modem
/dev/tty.Bluetooth-PDA-Sync
/dev/cu.Bluetooth-Modem
/dev/cu.Bluetooth-PDA-Sync

None of them helps in transferring the compiled program to the board.
How can I see/enable the /dev/tty.usbmodem* ports so that I can communicate using that?
Or any other option?

Thanks

A different USB cable did the trick. It works now!