)
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