Int B3 Fn 7E  - Zipkey - Get Name Of Primary City For A Zipcode Region     [U]

   AH = 7Eh
   DX = zipcode region (0-999)
   ES:DI -> buffer for name

Return: CF set on error
       AL = FFh region does not exist
   CF clear if successful
       AL = ZIPKEY state code
       ES:DI points one byte beyond end of name

See Also: AH=76h