code: def rl(self, r):
          
          if self.C is None or not is_number(self.regs[r]):
              self.set(r, None)
              self.set_flag(None)
              return
  
          self.rlc(r)
          tmp = self.C
          v_ = self.getv(self.regs[r])
          self.C = v_ & 1
          self.regs[r] = str((v_ & 0xFE) | tmp)
docs: Like the above, bus uses carry