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

XMS API implemented via VXMS.DLL VDD

mov ax,4310h
int 2Fh
mov word ptr [XMSCALL],bx
mov word ptr [XMSCALL+2],es
mov ah,00h
call [XMSCALL]

Function	Description	Status	Version
00h	Get XMS Version Number	2
01h	Request High Memory Area	2
02h	Release High Memory Area	2
03h	Global Enable A20	2
04h	Global Disable A20	2
05h	Local Enable A20	2
06h	Local Disable A20	2
07h	Query A20	2
08h	Query Free Extended Memory	2
09h	Allocate Extended Memory Block	2
0Ah	Free Extended Memory Block	2
0Bh	Move Extended Memory Block	2
0Ch	Lock Extended Memory Block	2
0Dh	Unlock Extended Memory Block	2
0Eh	Get Handle Information	2
0Fh	Reallocate Extended Memory Block	2
10h	Request Upper Memory Block	2
11h	Release Upper Memory Block	2
12h	Realloc Upper Memory Block	2
88h	Query any Free Extended Memory	3
89h	Allocate any Extended Memory Block	3
8Eh	Get Extended EMB Handle	3
8Fh	Realloc any Extended Memory	3