fn op_Fx0A(&mut self, x: usize) {
        self.waiting_for_keypad = true;
        self.keycode_register = x;

        self.pc.goto_next();
    }
// Wait for a key press. Store keycode into register Vx.
Wait for a key press. Store keycode into register Vx.
Wait for a key press . Store keycode into register Vx .
fn op_Fx0A(&mut self, x: usize) {
        self.waiting_for_keypad = true;
        self.keycode_register = x;
        self.pc.goto_next();
    }
fn op_Fx0A ( & mut self , x : usize ) { self . waiting_for_keypad = true ; self . keycode_register = x ; self . pc . goto_next ( ) ; }
Wait for a key press.
Wait for a key press .
&mut self
x
usize
&mut self
x
usize