After graduating from Rice University, he was a programmer working for Western Geophysical in Houston, Texas. He received an M.S. from University of California, Berkeley in 1976, and went to work at Atari in November 1977.
His first effort at Atari was Slot Racers for the Atari 2600. While he was working on it, he had discovered and played Crowther and Woods' Adventure at the Stanford Artificial Intelligence Laboratory, and decided that a graphical video game version "would be cool". However, with 128 bytes of RAM and 4096 bytes of ROM, Atari's Adventure was a much simpler program, and with only a joystick for input, the set of commands was necessarily brief. Even so, Adventure was a hit upon its 1978 release, and eventually sold a million copies.
Robert then did a BASIC Programming cartridge that came in 1979.
He quit Atari and founded The Learning Company in 1980.