diff --git a/src/processor/memory/mmio/apu.rs b/src/processor/memory/mmio/apu.rs
index 1fe6a37..f3c1a7a 100644
--- a/src/processor/memory/mmio/apu.rs
+++ b/src/processor/memory/mmio/apu.rs
@@ -136,6 +136,12 @@ impl Apu {
             0xFF23 => {
                 self.mem[reg(addr)] = (self.mem[reg(addr)] & 0b10111111) | (data & 0b01000000)
             }
+            0xFF24 => {
+                self.vin.left = get_bit(data, 7);
+                self.vin.right = get_bit(data, 3);
+                self.vol_left = (data & 0b1110000) >> 4;
+                self.vol_right = data & 0b111;
+            }
             0xFF25 => {
                 self.channels.one.pan_right = get_bit(data, 0);
                 self.channels.two.pan_right = get_bit(data, 1);