No, you are definitely thinking of Explorers.
Flight of the Navigator is similar, but does not have the specific computer sphere scene. In the movie, River Phoenix becomes privy to a computer program that lets him devise the spherical devise. They then put together the "spaceship" that lets them fly beyond.
Both movies you should watch, of course, if you were a kid in the '80s. Explorers and Flight of the Navigator are really two of the better children's movies of that period.l