Int 1A Fn FF  - Rightime V1.1 - Permanently Disable                        [U]

   AH = FFh
Program: RighTime is a TSR by G.T. Becker which continuously adjusts the
     system time to correct for clock drift

Note:  upon being permanently disabled, RighTime closes the file handle
     referencing its executable (which is updated with time correction
     information every two minutes while RighTime is enabled).