fn dec(&mut self) -> bool {
        self.fetch();

        let sub = self.fetched as u16 - 1;
        self.write(self.eff_addr, (sub & 0x00FF) as u8);

        self.flags.set(Flags::N, sub & 0x0080 != 0);
        self.flags.set(Flags::Z, sub & 0x00FF == 0);

        false
    }
// DEC: Decrement memory
// Affects: N Z
Decrement memory
Affects: N Z
Decrement memory Affects : N Z
fn dec(&mut self) -> bool {
        self.fetch();
        let sub = self.fetched as u16 - 1;
        self.write(self.eff_addr, (sub & 0x00FF) as u8);
        self.flags.set(Flags::N, sub & 0x0080 != 0);
        self.flags.set(Flags::Z, sub & 0x00FF == 0);
        false
    }
fn dec ( & mut self ) -> bool { self . fetch ( ) ; let sub = self . fetched as u16 - 1 ; self . write ( self . eff_addr , ( sub & 0x00FF ) as u8 ) ; self . flags . set ( Flags :: N , sub & 0x0080 != 0 ) ; self . flags . set ( Flags :: Z , sub & 0x00FF == 0 ) ; false }
DEC: Decrement memory
Affects: N Z
DEC : Decrement memory Affects : N Z
&mut self