The Pentagon has picked Aberdeen Proving Ground as one of four defense research centers in the nation to participate in a planned $1.4 billion program to modernize the military's advanced computers.

Proving ground researchers use "supercomputers" to develop weaponry and other materiel. The modernization program announced this week will allow the replacement of outdated equipment, officials said.

Aberdeen scientists have been involved in developing advanced computers for nearly 50 years, including the ENIAC, or Electronic Numerical Integrator and Calculator, the world's first electronic digital computer.

Though exact figures were unavailable, a Defense Department official said yesterday that Aberdeen's participation could involve a maximum investment of $40 million in equipment and $20 million a year in operating money.

The official, Anthony Pressley, executive director of the Defense Department's high-performance computing modernization program in Alexandria, Va., said the Army Research Laboratory (ARL) at Aberdeen will be receiving the money.

He said Army researchers need more modern computers to develop better anti-tank weapons, missile-defense systems and other equipment.

The four computing centers will be used by researchers throughout the Defense Department, Mr. Pressley said.

The other centers are an Air Force lab in Dayton, Ohio, a Navy lab in Bay St. Louis, Miss., and an Army Corps of Engineers lab in Vicksburg, Miss.

The official said the modernization effort is an attempt provide defense researchers with the same technological advances available in the private sector.

Sen. Paul S. Sarbanes, D-Md., said the modernization will bolster Aberdeen's position as a major defense research center and further insulate the installation from defense cuts.