)
Call the XMS driver "Query free extended memory" function with:
AH = 08h
BL = 00h (some implementations leave BL unchanged on success)
Return: AX = size of largest extended memory block in KB
DX = total extended memory in KB
BL = error code (00h,80h,81h,A0h) (see #02775)
Note: this function does not include the HMA in the returned memory sizes
SeeAlso: #02750,#02757,#02759,#02771