The CODA event format description provides a definition for the format of a file containing CODA format events. A library is provided with CODA for writing and reading files in this format. This library is used by the event recorder. Two additional tools for manipulating data files, cefdmp and xcefdmp. The code event format tags event fragments and the data banks they contain with a numerical value. The user provides a dictionary to translate the numerical values into human readable text descriptions. The cefdmp and xcefdmp tools take a coda data file and its associated dictionary and displays the data contained in the event as a numerical dump (decimal or hexadecimal). In the case of xcefdmp the event is displayed graphically as a tree reflecting the hierarchy of banks inside the event. The xcefdmp can be used to spy on a live datastream by connecting to the DD or ET system.