A federal judge has sentenced a teenager to nine months in prison for tapping into U.S. military computers and copying highly sensitive computer programs valued at $1.2 million.

Herbert Zinn Jr., 18, of Chicago, was also ordered Tuesday by U.S. District Judge Paul Plunkett to pay a $10,000 fine and serve 21/2 years' probation.Zinn was 17 when he broke into computers at AT&T, NATO and the Defense Department. His case is one of the first ever brought under the Computer Fraud and Abuse Act of 1986.

"Our intention is to prosecute such cases aggressively in the future," said U.S. Attorney Anton Valukas.

In sentencing Zinn, Plunkett said he hoped that the young man's brush with the law would direct his extraordinary computer skills toward legal outlets.

Zinn was convicted Jan. 23 of breaking into AT&T and U.S. government computers in three states, illegally copying more than $1.2 million worth of computer software and of illegally publishing computer passwords on computer bulletin boards in Chicago and Texas.

Court documents indicate that Zinn, a high school dropout who used the name Shadow Hawk, broke into AT&T computers in suburban Naperville and New Jersey, as well as NATO computers run by AT&T in Burlington, N.C., and at Robbins Air Force Base in Georgia. The intrusions took place from July to September 1987.

By entering the computers, Zinn caused $174,000 worth of damage to AT&T equipment, according to the court documents.