fix(apu): increase size of the audio buffer

src/apu/gen.rs

@@ -3,7 +3,7 @@ use rtrb::{Consumer, Producer, PushError, RingBuffer};
 
 pub(crate) const SAMPLE_RATE: u32 = 48000; // Hz
 const CHANNEL_COUNT: usize = 2;
-const BUFFER_CAPACITY: usize = 512 * CHANNEL_COUNT; // # of samples * the # of channels
+const BUFFER_CAPACITY: usize = 2048 * CHANNEL_COUNT; // # of samples * the # of channels
 
 pub struct AudioSPSC<T> {
     inner: RingBuffer<T>,
@@ -43,6 +43,7 @@ impl<T> SampleProducer<T> {
         self.inner.push(value)
     }
 
+    #[allow(dead_code)]
     pub(crate) fn available(&self) -> bool {
         self.inner.slots() > 2
     }

src/bus.rs

@@ -374,17 +374,6 @@ impl BusIo for Bus {
     }
 }
 
-impl Bus {
-    pub(crate) fn read_word(&self, addr: u16) -> u16 {
-        (self.read_byte(addr + 1) as u16) << 8 | self.read_byte(addr) as u16
-    }
-
-    pub(crate) fn write_word(&mut self, addr: u16, word: u16) {
-        self.write_byte(addr + 1, (word >> 8) as u8);
-        self.write_byte(addr, (word & 0x00FF) as u8);
-    }
-}
-
 impl Bus {
     fn interrupt_flag(&self) -> InterruptFlag {
         // Read the current interrupt information from the PPU