// This file is part of www.nand2tetris.org // and the book "The Elements of Computing Systems" // by Nisan and Schocken, MIT Press. // File name: projects/12/SysTest/Main.jack /** Test program for the OS Sys class. */ class Main { /** Tests the wait method of the Sys class. */ function void main() { var char key; do Output.printString("Wait test:"); do Output.println(); do Output.printString("Press any key. After 2 seconds, another message will be printed:"); while (key = 0) { let key = Keyboard.keyPressed(); } while (~(key = 0)) { let key = Keyboard.keyPressed(); } do Sys.wait(2000); do Output.println(); do Output.printString("Time is up. Make sure that 2 seconds elapsed."); return; } }