About 2,000 federally chartered savings and loan associations could get into the data processing business in a small way if a rule proposed last week by the Federal Home Loan Bank Board is made final. The proposal would allow the banks to computerize all relevant financial data they might need and to sell that data to other federally chartered S&Ls. In addition, the banks could sell either excess computer capacity or even some combination of computer time and finished programs to customers other than banks provided their non-bank computer business is less than half of their total data processing sales.

In practice, that would mean that instead of using their computers for only bookkeeping and record-keeping functions, the banks could get into more sophisticated realms like forecasting, sell some of these services to other banks or corporations and gain a needed source of new income. This would not please the Association of Data Processing Service Organizations, whose members aren't eager for any more competitors even in an expanding market.

But one industry analyst says that, in practice, "in the successful end of the data processing world you can beat a bank without pulling out your gun. They're doing this part-time left-handed."