From d3a0cc3a8ba6dfeb64d3faeffdeb6845b60e5840 Mon Sep 17 00:00:00 2001
From: Yuchen Pei <me@ypei.me>
Date: Sat, 20 Jan 2018 15:41:49 +0100
Subject: rearranged the dir for github

- removed tools and pdfs
- rearranged the projects dirs
- added md files
- other minor changes
---
 jackos/Sys.jack | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 jackos/Sys.jack

(limited to 'jackos/Sys.jack')

diff --git a/jackos/Sys.jack b/jackos/Sys.jack
new file mode 100644
index 0000000..53c078c
--- /dev/null
+++ b/jackos/Sys.jack
@@ -0,0 +1,51 @@
+// 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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