src/cartridge.rs

@@ -75,7 +75,7 @@ impl Cartridge {
     }
 
     fn detect_rom_info(memory: &[u8]) -> RomSize {
-        let id = memory[ROM_SIZE_ADDRESS];
+        let id = dbg!(memory[ROM_SIZE_ADDRESS]);
         id.into()
     }
 

src/timer.rs

@@ -21,28 +21,17 @@ impl Timer {
         use State::*;
         use TimerSpeed::*;
 
-        match self.state {
+        if let TIMAOverflow(step) | AbortedTIMAOverflow(step) = self.state {
-            TIMAOverflow(_) | AbortedTIMAOverflow(_) => self.state = self.state.next(),
+            if step < 4 {
-            LoadTMA => {
+                self.state = TIMAOverflow(step + 1);
+                return;
+            }
+
+            if self.state == TIMAOverflow(step) {
                 self.counter = self.modulo;
                 self.interrupt = true;
-
-                self.state.next();
-            }
-            Normal => {}
-        }
-
-        if let TIMAOverflow(step) | AbortedTIMAOverflow(step) = self.state {
-            if step < 3 {
-                self.state = self.state.next();
-            } else {
-                if self.state == TIMAOverflow(step) {
-                    self.counter = self.modulo;
-                    self.interrupt = true;
-                }
-
-                self.state = Normal;
             }
+            self.state = Normal;
         }
 
         self.divider = self.divider.wrapping_add(1);
@@ -78,12 +67,14 @@ impl Timer {
         use State::*;
 
         match self.state {
-            Normal | AbortedTIMAOverflow(_) => self.counter = byte,
+            Normal => self.counter = byte,
             TIMAOverflow(step) => {
-                self.counter = byte;
+                if step < 4 {
-                self.state = AbortedTIMAOverflow(step);
+                    self.counter = byte;
+                    self.state = AbortedTIMAOverflow(step);
+                }
             }
-            LoadTMA => {}
+            AbortedTIMAOverflow(_) => self.counter = byte,
         }
     }
 
@@ -182,19 +173,4 @@ enum State {
     TIMAOverflow(u8),
     AbortedTIMAOverflow(u8),
     Normal,
-    LoadTMA,
-}
-
-impl State {
-    fn next(&self) -> Self {
-        use State::*;
-
-        match self {
-            Normal | LoadTMA => Normal,
-            TIMAOverflow(3) => LoadTMA,
-            AbortedTIMAOverflow(3) => Normal,
-            TIMAOverflow(step) => TIMAOverflow(step + 1),
-            AbortedTIMAOverflow(step) => AbortedTIMAOverflow(step + 1),
-        }
-    }
 }