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// 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/Sys.jack
/**
* A library that supports various program execution services.
*/
class Sys {
/** Performs all the initializations required by the OS. */
function void init() {
do Keyboard.init();
do Math.init();
do Memory.init();
do Output.init();
do Screen.init();
do Main.main();
do Sys.halt();
return;
}
/** Halts the program execution. */
function void halt() {
while (true){
}
return;
}
/** Waits approximately duration milliseconds and returns. */
function void wait(int duration) {
var int i, j;
let i = 0;
while (i < duration){
let i = i + 1;
let j = 0;
while (j < 318){
let j = j + 1;
}
}
return;
}
/** Displays the given error code in the form "ERR<errorCode>",
* and halts the program's execution. */
function void error(int errorCode) {
do Output.printString("ERR");
do Output.printInt(errorCode);
return;
}
}
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