Remove Beep from Delay Timer

src/emu.rs

@@ -28,7 +28,7 @@ impl Default for Chip8 {
             stack: [0; 16],
             memory: [0; 4096],
             delay: Default::default(),
-            sound: Default::default(),
+            sound: Timer::default().with_beep(),
             key: Default::default(),
             display: Default::default(),
             request_redraw: false,

src/periph.rs

@@ -61,6 +61,7 @@ impl Default for Display {
 pub struct Timer {
     remaining: u8,
     enabled: bool,
+    beep_enabled: bool,
 }
 
 impl Default for Timer {
@@ -68,11 +69,17 @@ impl Default for Timer {
         Timer {
             remaining: 0,
             enabled: false,
+            beep_enabled: false,
         }
     }
 }
 
 impl Timer {
+    pub fn with_beep(mut self) -> Self {
+        self.beep_enabled = true;
+        self
+    }
+
     pub fn set(&mut self, secs: u8) {
         self.remaining = secs;
         self.enabled = true;
@@ -88,7 +95,10 @@ impl Timer {
 
             if self.remaining == 0 {
                 self.enabled = false;
-                Self::beep();
+
+                if self.beep_enabled {
+                    Self::beep();
+                }
             }
         }
     }