A zero with a positive or negative sign in EBCDIC is x'C0' and x'D0' which is also the representation for special characters { and }. Using the modified-zoned-decimal these translate to the ASCII values for { and } which is x'7B' and x'7D' and the rightmost nibble is no longer the binary value of the digit.
Chicago Midway International Airport (IATA: MDW, ICAO: KMDW, FAA LID: MDW) is an international airport on the southwest side of Chicago, Illinois, eight miles (13 km) from the Loop. Dominated by low-cost carrier Southwest Airlines, Midway is the Dallas-based carrier's largest focus city, as of 2013.
O'Hare International Airport is the main one, while Chicago Midway International Airport is considered the secondary tarmac. O'Hare sits 17 miles northwest of the Loop. It provides plenty of amenities to keep you entertained while you wait for your flight or transportation into Chi-Town.