Int 1F Fn 90  - Nec Pc-9801 - Copy Extended Memory                         [J]

   AH = 90h
   ES:BX -> global descriptor table (see #0425 at INT 15/AH=87h)
   CX = number of bytes to copy
   SI = 0000h
   DI = 0000h

Return: CF clear if successful
   CF set on error
   ???

See Also: INT 15/AH=87h