Note: The following won't unlock Neo and Morpheus as playable characters, no matter what the messages that appear state. In the Hacking mode, after unlocking the DECODE.EXE program, type "DECODE IAHSZWQLFZC". The following message will appear:
"Valid code found. MORPHEUS"
You will also hear Morpheus say "You have access." Morpheus and Neo are now viewable in the "view" section of Hacking mode, where you can get the stats and pictures of various characters in the game.
If you type "DECODE DBIUHU7XDTSMZYO", the following message will appear:
"Valid code found. NEO UNLOCKED"
You will also hear Morpheus say "You have access." Even more characters are now viewable, such as the Merovingian and Bane.