INT B3 - ZIPKEY - LOOK UP STATE CODE FOR ZIPCODE AH = 75h DX = zipcode region (0-999) CH = last two digits of zipcode (0-99) Return: CF set on error (zipcode not found) AL = suggested state code, FFh if none CF clear if successful AL = ZIPKEY state code BX = area code (v2.0+) SeeAlso: AH=76h,AH=79h