1 files changed, 31 insertions, 0 deletions
diff --git a/apps/ex3.mu b/apps/ex3.mu
new file mode 100644
index 00000000..155457c6
--- /dev/null
+++ b/apps/ex3.mu
@@ -0,0 +1,31 @@
+# Draw pixels in response to keyboard events, starting from the top-left
+# and in raster order.
+#
+# To build a disk image:
+#   ./translate apps/ex3.mu        # emits code.img
+# To run:
+#   qemu-system-i386 code.img
+# Or:
+#   bochs -f bochsrc               # bochsrc loads code.img
+#
+# Expected output: a new green pixel starting from the top left corner of the
+# screen every time you press a key (letter or digit)
+
+fn main screen: (addr screen), keyboard: (addr keyboard), data-disk: (addr disk) {
+  var x/ecx: int <- copy 0
+  var y/edx: int <- copy 0
+  {
+    var key/eax: byte <- read-key keyboard
+    compare key, 0
+    loop-if-=  # busy wait
+    pixel-on-real-screen x, y, 0x31/green
+    x <- increment
+    compare x, 0x400/screen-width=1024
+    {
+      break-if-<
+      y <- increment
+      x <- copy 0
+    }
+    loop
+  }
+}