The Supreme Court, in a 4-to-4 vote, yesterday affirmed a lower court ruling that instructions regulating the internal operation of a computer can be patented.

It was the second time in the last week in which the high court has edged back from its previous position that computer programs and mathematical equations by themselves are not patentable subject matter.

The tie vote affirming the lower court was a victory for two Honeywell Information Systems inventors who sought a patent on an invention that directs the transfer of data within a computer.

Chief Justice Warren Burger did not take part in considering the case.

The inventors, John J. Bradley and Benjamin S. Franklin, sought the patent in 1975. A patent examiner rejected their plea, ruling the inventors used well-known components and combined them with an alogarithm -- a mathematical formula that prior court decsions have said cannot be patented.

The Patent and Trademark Office Board of Appeals agreed with the examiner, ruling that an "improved method of calculation, even when tied to a specific end use," cannot be patented.

But the Court of Customs and Patent Appeals reversed the decision, finding that the invention used computer hardware but not a mathematical formula.

In another case, the Supreme Court yesterday blocked the release of secret information the government says could show tax cheaters how to avoid getting caught.

The justices postponed indefinitley the effect of court orders forcing the Bureau of Economic Analysis to release 58 computer tapes to Susan and Philip Long of Bellevue, Wash.

The court's brief order ended a week of intense legal maneuvering by government lawyers and provided the latest frustration for the Longs, who sued in 1975 to obtain the tapes under the Freedon of Information Act.