Table of Contents

Note: This API call is for DOS and Win16 personality only. Use Family API for portability.

2018/09/07 05:04 · prokushev · 0 Comments

Int 21H, AH=48H

Version

2 and higher

Brief

ALLOCATE MEMORYY

Family API

DosAllocHuge, DosAllocSeg

Input

AH = 48h
BX = number of paragraphs to allocate

Return

CF clear if successful
  AX = segment of allocated block
CF set on error
  AX = error code (07h,08h) (see #01680 at AH=59h/BX=0000h)
  BX = size of largest available block

Macro

INCLUDE DOS.INC
 
ALLOCATE_MEMORY bytes

Notes

DOS 2.1-6.0 coalesces free blocks while scanning for a block to allocate

.COM programs are initially allocated the largest available memory block, and should free some memory with AH=49h before attempting any allocations

under the FlashTek X-32 DOS extender, EBX contains a protected-mode near pointer to the allocated block on a successful return

See also

INT 21H: 49H, 4AH, 58H

Note

Text based on Ralf Brown Interrupt List Release 61

2018/09/04 17:23 · prokushev · 0 Comments