en:docs:dos:api:int21:49

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

2018/09/07 07:04 · prokushev

Int 21H, AH=49H

Version

2 and higher

Brief

FREE MEMORY

Family API

Input

AH = 49h
ES = segment of block to free

Return

CF clear if successful
CF set on error
    AX = error code (07h,09h) (see #01680 at AH=59h/BX=0000h)

Notes

	apparently never returns an error 07h, despite official docs; DOS 2.1+
  code contains only an error 09h exit
DOS 2.1-6.0 does not coalesce adjacent free blocks when a block is
  freed, only when a block is allocated or resized
the code for this function is identical in DOS 2.1-6.0 except for
  calls to start/end a critical section in DOS 3.0+
        

See also

AH=48h,AH=4Ah

Note


en/docs/dos/api/int21/49.txt · Last modified: 2021/05/01 18:03 by prokushev