sudo tar -x -C /usr/local -f ~/Downloads/nand2tetris.tgzOtherwise, open the Terminal utility and enter this command:
sudo tar -x -C /usr/local -f ~/Downloads/nand2tetris.tarThe use of the sudo command on the two lines above will require you to enter your password. Please note that you won't see any keystroke echoes (no asterisks) appear when you type your password.
HardwareSimulatorThe HardwareSimulator should run.