From 2609fb966d934fa6396e3e972ef146db1b28806e Mon Sep 17 00:00:00 2001
From: Alex Janka <alex@alexjanka.com>
Date: Mon, 20 Feb 2023 16:21:16 +1100
Subject: [PATCH] fix masked io in apu

---
 src/processor/memory/mmio/apu.rs          |  6 +++++-
 src/processor/memory/mmio/apu/channels.rs | 15 +++++++--------
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/src/processor/memory/mmio/apu.rs b/src/processor/memory/mmio/apu.rs
index 1ef6d17..869e040 100644
--- a/src/processor/memory/mmio/apu.rs
+++ b/src/processor/memory/mmio/apu.rs
@@ -239,7 +239,11 @@ impl Apu {
             }
             0xFF26 => {
                 // NR52 - Sound on/off
-                let mut v = if self.apu_enable { 1 << 7 } else { 0 };
+                let mut v = if self.apu_enable {
+                    0b11111111
+                } else {
+                    0b01111111
+                };
                 v = set_or_clear_bit(v, 0, self.channels.one.enabled);
                 v = set_or_clear_bit(v, 1, self.channels.two.enabled);
                 v = set_or_clear_bit(v, 2, self.channels.three.enabled);
diff --git a/src/processor/memory/mmio/apu/channels.rs b/src/processor/memory/mmio/apu/channels.rs
index 0d6cd4d..089b00e 100644
--- a/src/processor/memory/mmio/apu/channels.rs
+++ b/src/processor/memory/mmio/apu/channels.rs
@@ -220,7 +220,7 @@ impl PwmChannel {
 
     pub(super) fn get_sweep_register(&self) -> u8 {
         set_or_clear_bit(
-            ((self.sweep.pace & 0b1110000) << 4) | (self.sweep.slope & 0b111),
+            (0b10000000 | (self.sweep.pace << 4) & 0b1110000) | (self.sweep.slope & 0b111),
             3,
             self.sweep.mode == EnvelopeMode::Decrease,
         )
@@ -401,13 +401,12 @@ impl WaveChannel {
     }
 
     pub(super) fn get_volume(&self) -> u8 {
-        0b10011111
-            & (match self.volume {
-                ShiftVolumePercent::Zero => 0b00,
-                ShiftVolumePercent::TwentyFive => 0b11,
-                ShiftVolumePercent::Fifty => 0b10,
-                ShiftVolumePercent::OneHundred => 0b01,
-            } << 5)
+        match self.volume {
+            ShiftVolumePercent::Zero => 0b10011111,
+            ShiftVolumePercent::TwentyFive => 0b11111111,
+            ShiftVolumePercent::Fifty => 0b11011111,
+            ShiftVolumePercent::OneHundred => 0b10111111,
+        }
     }
 
     pub(super) fn update_wavelength_low(&mut self, data: u8) {