Compatibility: XMS 2.0+
Expects: AH    08H
                                                                  
Returns: AX    size of largest free XMB, in kbytes
BL    XMS error code (if BL >= 80H)
                                                                  
Info: This obtains the size, in K-bytes, of the largest free block of
extended memory.

Notes: The 64K-16 bytes of the HMA  are not included in this
calculation.

See Also: XMS Functions
- -

XMS 08H: Query Free Extended Memory