by hand which was wired onto the board. A prototype of Asteroids was well received by several Atari staff and engineers, who "wander[ed] between labs, passing comment and stopping to play as they went". Logg was often asked when he would be leaving by employees eager to play the prototype, so he created a second prototype for staff to play. Atari tested the game in arcades in Sacramento, California, and also observed players during focus group sessions at Atari. Players used to Spacewar! struggled to maintain grip on the thrust button and requested a joystick; players accustomed to Space Invaders noted they get no break in the game. Logg and other engineers observed proceedings and documented comments in four pages. Asteroids slows down as the player gains 50–100 lives, because there is no limit to the number of lives displayed. The player can "lose" the game after more than 250 lives are collected. Ports Asteroids was released for the Atari VCS (later renamed the Atari 2600) and Atari 8-bit family in 1981, then the Atari 7800 in 1986. A port for the Atari 5200, identical to the Atari 8-bit computer version, was in development in 1982, but was not published. The Atari 7800 version was a launch title and includes cooperative play; the asteroids have colorful textures and the "heartbeat" sound effect remains intact. Programmers Brad Stewart and Bob Smith were unable to fit the Atari VCS port into a 4 KB cartridge. It became the first game for the console to use bank switching, a technique that increases ROM size from 4 KB to 8 KB. Reception Asteroids was immediately successful upon release. It displaced Space Invaders by popularity in the United States and became Atari's best selling arcade game of all time, with over 70,000 units sold. Atari earned an estimated $150 million in sales from the game, and arcade operators earned a further $500 million from coin drops. Atari had been in the process of manufacturing another vector game, Lunar Lander, but demand for Asteroids was so high "that several hundred Asteroids games were shipped in Lunar Lander cabinets". Asteroids was so popular that some video arcade operators had to install large boxes to hold the number of coins spent by players. It replaced Space Invaders at the top of the US RePlay amusement arcade charts in April 1980, though Space Invaders remained the top game at