Int 20h                 Terminate Program                          Superseded

    Terminates the current program and returns control to its parent
    program.

        Note    Int 20h has been superseded. Programs should use
                End Program (Int 21h, function 4ch).

        Entry   CS = Segment of PSP

        Return  This interrupt does not return

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    This interrupt is intended to be used by .COM programs. When a
    program issues Int 20h, the CS register must contain the segment
    address of the program segment prefix (PSP).

    Int 20h carries out the following actions:

    - Flushes the file buffers and closes files, unlocking any regions
      locked by the program.
    - Restores interrupt 22h, 23h, and 24h vectors from the addresses
      saved in the PSP.
    - Frees any memory owned by the terminating program.
    - Transfers control to the address specified by offset 0Ah
      (termination address) in the PSP.