Fixes

src/cpu/mod.rs

@@ -665,11 +665,11 @@ impl Cpu {
             self.delay -= 1;
             return 1;
         }
-
+        let clock = self.clock;
         self.handle_interrupts();
 
         // back up clock so we know how many cycles we complete
-        let clock = self.clock;
+
         self.before_clock = self.clock;
         let opcode = <usize>::from(self.read(self.pc));
         self.addresses_fetched.insert(self.pc);

src/main.rs

@@ -43,7 +43,7 @@ const RNG_SEED: u32 = 0x35234623;
 const DISABLE_START_PRESSES_AFTER: usize = usize::MAX;
 
 // The rate at which seed inputs become corrupted..
-const MUTATION_RATE: f64 = 0.025;
+const MUTATION_RATE: f64 = 0.05;
 
 // The rate at which seed inputs may become soft resets..
 const MUTATION_RATE_SOFT_RESET: f64 = 0.00;

src/ppu/rendering.rs

@@ -106,13 +106,11 @@ impl super::Ppu {
             palette_address += background_pixel; // Pixel value from tile data
         } else if background_pixel != 0 && sprite_pixel != 0 {
             if self.sprite_indexes[current_sprite] == 0 {
-                if x != 255 {
+                if x != 255 && y != 0 {
                     // Sprite 0 does not hit At x=255, for an obscure reason related to the pixel pipeline.
                     // don't access index current_sprite. need to know which sprite we're on horizontally.
                     self.sprite_zero_hit = true;
                 }
-                // TODO sprite zero should not hit when y == 255 (+1) == 0...
-                //
             }
             if self.sprite_attribute_latches[current_sprite] & (1 << 5) == 0 {
                 // sprite has high priority