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====== 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 =====

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

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