swim3_action
swim3_action(fs, MOTOR_OFF);
swim3_action(fs, MOTOR_ON); /* necessary? */
swim3_action(fs, MOTOR_OFF);
swim3_action(fs, SETMFM);
swim3_action(fs, SEEK_POSITIVE);
swim3_action(fs, SEEK_NEGATIVE);
swim3_action(fs, EJECT);
swim3_action(fs, MOTOR_ON);
swim3_action(fs, SETMFM);
swim3_action(fs, MOTOR_OFF);