This paper examines the patterns of communication on computer office automation systems (COA) in terms of organizational functi ons. A new category system is devised. Two areas of organizationally functional communi cation are defined: Operational Control Communication and Managerial Control Communication, the latter being divided into organizing and problem solving communication. Messages sent on a COA memorandum system are coded according to the newly defined classification scheme and the trends are examined. Evidence is presented that Probl em Sol ving Communication declines, Operational Communication increases, and Organizing Communication maintains a consistantly high 1 evel across time. The COA memorandum systen is suggested to be primarily serving an organizing function in the organization being examined.