Int 21 Fn 4402  - Highumm.sys V1.17+ - Ioctl - Get API Address             [m]

   AX = 4402h
   BX = handle for device "KSP$UMM"
   CX = 0004h
   DS:DX -> DWORD to hold entry point

Return: CF set on error
       AX = error code (see AH=59h)
   CF clear if successful
       AX = number of bytes read
Program: HIGHUMM.SYS is part of the shareware "The Last Byte" memory management
     package by Key Software Products

See Also: AX=4402h"LASTBYTE"

Call HIGHUMM.SYS entry point with:
   AH = 00h allocate UMB (same as XMS function 10h) (see INT 2F/AX=4310h)
       DX = size in paragraphs

       Return: BX = segment number (if successful)
           DX = size of requested block/size of largest block
   AH = 01h deallocate UMB (same as XMS func 11h) (see INT 2F/AX=4310h)
       DX = segment number of UMB
   AH = 02h request a bank-switched memory block
       DX = size in paragraphs

       Return: BX = segment number (if successful)
           DX = size of requested block/size of largest block
   AH = 03h release a bank-switched memory block
       DX = segment number
   AH = 04h transfer data to/from high memory
       DS:SI -> source
       ES:DI -> destination
       CX = length in bytes

       Note: enables bank-switched memory, does the copy, then disables
       bank-switched memory
   AH = 05h get a word from bank-switched memory
       ES:DI -> word to read

       Return: DX = word
   AH = 06h put a word to bank-switched memory
       ES:DI -> word to write
       DX = word
   AH = 07h put a byte to bank-switched memory
       ES:DI -> byte to write
       DL = byte
   AH = 08h enable bank-switched memory
       DS:SI -> 6-byte status save area
   AH = 09h disable bank-switched memory
       DS:SI -> 6-byte save area from enable call (AH=08h)
   AH = 0Ah assign name to UMB or high bank-switched block
       DX = segment number
       DS:SI -> 8-byte blank-padded name
   AH = 0Bh locate UMB block by name
       DS:SI -> 8-byte blank-padded name

       Return: BX = segment number (if successful)
           DX = size of block
   AH = 0Ch locate bank-switched block by name
       DS:SI -> 8-byte blank-padded name

       Return: BX = segment number (if successful)
           DX = size of block

Return: AX = status code
       0001h successful
       0000h failed
       BL = error code
           80h not implemented
           B0h insufficient memory, smaller block available
           B1h insufficient memory, no blocks available
           B2h invalid segment number

Note:  only functions 00h and 01h are always available; the remaining
     functions are only enabled if the proper commandline switch is given