Bank compliance with currency rules has gained.

Federal authorities said that heavy fines levied against the Bank of Boston for illegally failing to report cash transactions has spurred other banks across the country to obey the law. Patrick J. Walsh, the special U.S. attorney who headed the Bank of Boston investigation, said U.S. banks now file more than twice as many currency transaction reports as at the end of 1984. Federal law requires banks to report to the IRS all cash transactions above $10,000 to crack down on laundering operations by drug dealers and organized crime.