Category: DOS kernel
INT 21 - DOS 2+ - FREE MEMORY 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+ SeeAlso: AH=48h,AH=4Ah