en:docs:dos:api:int21:51

Note: This API call is for DOS personality only. Use Family API for portability.

2018/09/07 07:04 · prokushev

Int 21H, AH=51H

Version

2 and higher

Brief

GET CURRENT PROCESS ID (GET PSP ADDRESS)

Family API

Input

AH = 51h

Return

 BX = segment of PSP for current process

Notes

DOS uses the current PSP address to determine which processes own files
  and memory; it corresponds to process identifiers used by other OSs
under DOS 2.x, this function cannot be invoked inside an INT 28h
  handler without setting the Critical Error flag
under DOS 3.0+, this function does not use any of the DOS-internal
  stacks and may thus be called at any time, even during another
  INT 21h call
supported by OS/2 compatibility box
identical to the documented AH=62h
this call was undocumented prior to the release of DOS 5.0
        

See also

AH=26h,AH=50h,AH=62h

Note


en/docs/dos/api/int21/51.txt · Last modified: 2021/05/02 07:17 by prokushev