Function 87h	 Extended Memory Block Move		 (286/386 machines only)
        AH      87h 
        CX      number of words to move 
        ES:SI   pointer to Global Descriptor Table (GDT) 
		offset 00h      null descriptor 
		       08h      uninitialized, will be made into GDT descriptor 
		       10h      descriptor for source of move 
		       18h      descriptor for destination of move 
		       20h      uninitialized, used by BIOS 
		       28h      uninitialized, will be made into SS descriptor 
return  CF      set on error 
        AH      status 
		00h     source copied into destination 
		01h     parity error 
		02h     interrupt error 
		03h     address line 20 gating failed