some fixes

lib/src/processor/memory.rs

@@ -319,9 +319,10 @@ where
             Address::Io(address) => {
                 if address.inner() == 0xFF50 {
                     self.bootrom = None
-                }
+                } else {
                     self.set_io(address, data)
                 }
+            }
             Address::Hram(address) => self.cpu_ram[address.get_local() as usize] = data,
             Address::InterruptEnable(_) => self.interrupts.set_enable_register(data),
         }

lib/src/processor/memory/mmio/gpu.rs

@@ -420,7 +420,7 @@ where
     }
 
     fn render_object(&mut self, scanline: u8, object: Object) {
-        let mut object_row = scanline - (object.y.wrapping_sub(16));
+        let mut object_row = scanline.wrapping_sub(object.y.wrapping_sub(16));
         if object.flags.y_flip {
             object_row = self.lcdc.obj_size.get_height() - (object_row + 1);
         }