Fixed occasional error with debug, and modified frame swapper

src/host/gfx.rs

@@ -92,6 +92,10 @@ impl FrameSwapper {
     pub fn to_boxed(swapper: FrameSwapper) -> Box<dyn WindowUpdater> {
         Box::new(swapper)
     }
+
+    pub fn swap(&mut self) {
+        std::mem::swap(&mut self.current.lock().unwrap().bitmap, &mut self.previous.lock().unwrap().bitmap);
+    }
 }
 
 impl WindowUpdater for FrameSwapper {
@@ -104,8 +108,6 @@ impl WindowUpdater for FrameSwapper {
     }
 
     fn update_frame(&mut self, width: u32, _height: u32, bitmap: &mut [u32]) {
-        std::mem::swap(&mut self.current.lock().unwrap().bitmap, &mut self.previous.lock().unwrap().bitmap);
-
         if let Ok(frame) = self.previous.lock() {
             for y in 0..frame.height {
                 for x in 0..frame.width {

src/peripherals/genesis/ym7101.rs

@@ -652,6 +652,7 @@ impl Steppable for Ym7101 {
                 system.get_interrupt_controller().set(true, 6, 30)?;
             }
 
+            self.swapper.swap();
             let mut frame = self.swapper.current.lock().unwrap();
             self.state.draw_frame(&mut frame);
 

src/system.rs

@@ -154,7 +154,9 @@ impl System {
         if self.debug_enabled.get() {
             let top = self.event_queue[self.event_queue.len() - 1].device.clone();
             if top.borrow_mut().as_debuggable().map(|debug| debug.debugging_enabled()).unwrap_or(false) {
-                self.debugger.borrow_mut().run_debugger(&self, top.clone()).unwrap();
+                if let Err(err) = self.debugger.borrow_mut().run_debugger(&self, top.clone()) {
+                    println!("Error: {:?}", err);
+                }
             }
         }
     }