SAN JOSE, Calif. (AP) _ It's not quite the year 2001, but Apple Computer Inc. has developed a HAL- like voice-activated computer that recognizes spoken commands and, sometimes, talks back, the company said Monday.

Computer experts and even a key competitor who saw the prototype Macintosh praised the leap in technology, but said such sophisticated voice-activated PCs won't reach desktops for years.

''I think Apple has produced a superb demo that's ahead of the game,'' said Wayne Rosing, who heads the advanced research lab at rival Sun Microsystems Inc. ''I was very impressed with how well the speech software had been integrated. But it's still a horse race to get a product to the market.''

Apple spokesman John Cook said the product was publicly demonstrated for the third time on Friday in Monterey at a conference. Previously, the voice- activated Macintosh was demonstrated at meetings in Tokyo and Southern California.

''Right now, it's basically something out of our laboratories,'' Cook said. ''But it has captured the imagination of people who have seen it. We're very interested in speech because Apple focuses on human interaction (with PCs) and speech is a very natural way to deal with your computer.''

The voice-activated Macintosh was able to change the type size of a document, program a video recorder, pay bills, find a name in an electronic telephone directory, call the number and perform other functions that normally require typed in commands or the use of a computer mouse.

Once it completed the commanded operation, the Macintosh also talked back, saying it was finished or asking whether the user wanted something else.

''Talking back is trivial, a lot of machines can do that,'' said Marvin Minsky, a computer science expert at Massachusetts Institute of Technology, who was at the Monterey demonstration. ''What I was really impressed with was the machine's ability to respond to connective speech, not just one-word-at-a- time commands.''

The Macintosh, which needs a powerful microprocessor to respond to 300 command words, is far from the conversational computer HAL from the movie ''2001: A Space Odyssey.''

Like HAL, the voice-activated Macintosh needs to be correctly addressed by a prearranged word before it will accept commands; Apple's prototype responds to the name ''Casper.'' But the Macintosh isn't highly functional.

The machine's developer, Kai-fu Lee, a former assistant professor at Carnegie Mellon University in Pittsburgh before joining Apple 18 months ago, said the voice-activated Macintosh needs a lot of work.

Lee said users must know how to talk so the machine can understand, that the machine's vocabulary must be expanded and other technical problems must be worked out, such as the ability to ignore background noise.

Still, Apple Chairman John Sculley said the voice-activated Macintosh amounted to a ''major breakthrough'' because the PC recognizes continuous speech rather than one-word commands.