Only turn on the column shift register output if we need it.

ROM2/motors.c

@@ -55,13 +55,13 @@ void motor_on(u8 slot) {
 			break;
 		default: /* < 8 */
 			motor_shift_send(1 << col); /* cols from 0..7 */
+			bclr((void*)&_io_ports[M6811_PORTA], PORTA_MOTOR_COL_DISABLE);
 	}
 
 	motor_shift_send(1 << (row-1)); /* rows from 1..8 here */
 
 	bclr((void*)&_io_ports[M6811_PORTA], PORTA_MOTOR_CLOCK);
 	bclr_changer_output(A3000_MOTOR_ROW_DISABLE);
-	bclr((void*)&_io_ports[M6811_PORTA], PORTA_MOTOR_COL_DISABLE);
 }
 
 void motors_off() {