 Cartridge software was so rare at first that "InfoWorld" joked in 1980 that Atari owners might have considered turning the slot "into a fancy ashtray".The magazine advised them to "clear out those cobwebs" for Atari's "Star Raiders", which became the platform's killer app, akin to VisiCalc for the Apple II in its ability to persuade customers to buy the computer.Chris Crawford and others at Atari published detailed technical information in "De Re Atari".