XMS Functions

 TECH Help! describes all services of the Extended Memory Specification
 version 2.0.  Version 2.0 has been standard since October, 1992 and is
 usually available on 286+ computers running DOS 4.0+.

 There are two parts to the XMS API.  The first uses INT 2fH 43xxH as a way
 to test for installation and to obtain the entry address for the other
 services.  After obtaining that address, you call it directly.  See
 INT 2fH 4310H for an example.

     See: INT 2fH 4300H (is HIMEM.SYS installed?)
          INT 2fH 4310H (get XMM entry address)
  ▀▀▀  ────────────────────────────────────────────────── General Functions
  00H  Get XMS version number
  ────────────────────────────────────────────────────── Standard Functions
  01H  Request high memory area
  02H  Release high memory area
  03H  Global enable A20
  04H  Global disable A20
  05H  Local enable A20
  06H  Local disable A20
  07H  Query A20 state
  ──────────────────────────────────────────────────── XMS Memory Functions
  08H  Query free extended memory
  09H  Allocate extended memory block
  0aH  Free extended memory block
  0bH  Move extended memory block
  0cH  Lock extended memory block
  0dH  Unlock extended memory block
  0eH  Get handle information
  0fH  Resize extended memory block
  ─────────────────────────────────────────────────────────── UMB Functions
  10H  Request upper memory block
  11H  Release upper memory block

See Also: XMS
          XMS Error Codes
          Expanded Memory Specification (EMS)
          DOS Interrupts
          Interrupts and BIOS Services