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====== Int 21H, AH=31H ======

===== Version =====

2 and higher

===== Brief =====

TERMINATE AND STAY RESIDENT

===== Family API =====


===== Input =====

        AH = 31h
        AL = return code
        DX = number of paragraphs to keep resident

===== Return =====

never returns

===== Notes =====

  the value in DX only affects the memory block containing the PSP;
          additional memory allocated via AH=48h is not affected
        the minimum number of paragraphs which will remain resident is 11h
          for DOS 2.x and 06h for DOS 3.0+
        most TSRs can save some memory by releasing their environment block
          before terminating (see #01378 at AH=26h,AH=49h)
        any open files remain open, so one should close any files which will
          not be used before going resident; to access a file which is left
          open from the TSR, one must switch PSP segments first (see AH=50h)

===== See also =====

 AH=00h,AH=4Ch,AH=4Dh,INT 20,INT 22,INT 27

===== Note =====

Text based on [[http://www.cs.cmu.edu/~ralf/files.html|Ralf Brown Interrupt List Release 61]]

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