)
Call the XMS driver "Allocate extended memory block" function with:
	AH = 09h
	DX = Kbytes needed
Return: AX = status
	    0001h success
		DX = handle for memory block
	    0000h failure
		BL = error code (80h,81h,A0h) (see #02775)
SeeAlso: #02758,#02761,#02764,#02765,#02766,#02772