pub(crate) fn add_vx_vy(&mut self, optcode: u16) {
        debug!("ADDVxVy => {:#X}", optcode);
        let (_x, _y) = vx_vy!(optcode);
        let _vx: usize = self.v[_x] as usize;
        let _vy: usize = self.v[_y] as usize;
        let result = add!(_vx, _vy);
        self.v[_x] = result as u8;
        self.v[0xF] = tern!(result > 255, 1, 0);
        if result > 255 {
            trace!("ADDVxVy => result({})", result);
        }
        self.pc += 2;
        //self.quit = true;
    }
/// 8xy4 - ADD Vx, Vy
/// Set Vx = Vx + Vy, set VF = carry.
/// The values of Vx and Vy are added together. If the result is greater than 8 bits (i.e., > 255,) VF is set to 1, otherwise 0. Only the lowest 8 bits of the result are kept, and stored in Vx.
ADD Vx, Vy
Set Vx = Vx + Vy, set VF = carry.
The values of Vx and Vy are added together. If the result is greater than 8 bits  VF is set to 1, otherwise 0. Only the lowest 8 bits of the result are kept, and stored in Vx.
ADD Vx Vy Set Vx = Vx + Vy set VF = carry . The values of Vx and Vy are added together . If the result is greater than 8 bits VF is set to 1 otherwise 0 . Only the lowest 8 bits of the result are kept and stored in Vx .
pub(crate) fn add_vx_vy(&mut self, optcode: u16) {
        debug!("ADDVxVy => {:#X}", optcode);
        let (_x, _y) = vx_vy!(optcode);
        let _vx: usize = self.v[_x] as usize;
        let _vy: usize = self.v[_y] as usize;
        let result = add!(_vx, _vy);
        self.v[_x] = result as u8;
        self.v[0xF] = tern!(result > 255, 1, 0);
        if result > 255 {
            trace!("ADDVxVy => result({})", result);
        }
        self.pc += 2;
        //self.quit = true;
    }
pub ( crate ) fn add_vx_vy ( & mut self , optcode : u16 ) { debug ! ( " " optcode ) ; let ( _x , _y ) = vx_vy ! ( optcode ) ; let _vx : usize = self . v [ _x ] as usize ; let _vy : usize = self . v [ _y ] as usize ; let result = add ! ( _vx _vy ) ; self . v [ _x ] = result as u8 ; self . v [ 0xF ] = tern ! ( result 255 1 0 ) ; if result > 255 { trace ! ( " " result ) ; } self . pc += 2 ; //self.quit = true; }
8xy4 - ADD Vx, Vy
Set Vx = Vx + Vy, set VF = carry.
8xy4 - ADD Vx Vy Set Vx = Vx + Vy set VF = carry .
&mut self
optcode
u16
&mut self
optcode
u16