Implement sound

README.md

@@ -22,10 +22,6 @@ which maps to
 	7 8 9 E
 	A 0 B F
 
-Sound
------
-Not yet implemented
-
 Games
 -----
 Get some [here](http://www.pong-story.com/chip8/) or [here](https://github.com/dmatlack/chip8/tree/master/roms)

sipsi-8.py

@@ -357,7 +357,15 @@ def tick_timers():
 		# The timer should tick down at 60Hz
 		delay_timer -= 1
 
-	# TODO: Do sth about the sound timer
+	# Play a sound using pyglet if we have a non-zero sound timer
+	# It will run asynchronously from the other parts, which means it
+	# won't experience slowdown similarily to the delay timer
+	# Unsure if this is good or bad
+	if sound_timer > 0:
+		# sound_timer is in the unit of 1/60th of a second, while
+		# Square takes length in seconds
+		pyglet.media.procedural.Square(sound_timer/60).play()
+		sound_timer = 0
 
 def advance_interpreter(dt):
 	global cpu_speed
@@ -610,7 +618,6 @@ def initialize_screen():
 
 def initialize_timers():
 	global delay_timer, sound_timer
-	# Tick timers down at 60Hz
 	delay_timer = 0
 	sound_timer = 0