In 1971 video games were played in computer science laboratories when the professors were not looking—and in very few other places. In 1973 millions of people in the United States and millions of others around the world had seen at least one video game in action. That game was Pong.
Two electrical engineers were responsible for putting this game in the hands of the public—Nolan Bushnell and Allan Alcorn, both of whom, with Ted Dabney, started Atari Inc. in Sunnyvale, Calif. Mr. Bushnell told Mr. Alcorn that Atari had a contract from General Electric Co. to design a consumer product. Mr. Bushnell suggested a Ping-Pong game with a ball, two paddles, and a score, that could be played on a television.
“There was no big contract,” Mr. Alcorn said recently. “Nolan just wanted to motivate me to do a good job. It was really a design exercise; he was giving me the simplest game he could think of to get me to play with the technology.”
The key piece of technology he had to toy with, he explained, was a motion circuit designed by Mr. Bushnell a year earlier as an employee of Nutting Associates. Mr. Bushnell first used the circuit in an arcade game called Computer Space, which he produced after forming Atari. It sold 2000 units but was never a hit.
This article was first published as “Pong: an exercise that started an industry.” It appeared in the December 1982 issue of IEEE Spectrum as part of a special report, “Video games: The electronic big bang.” A PDF version is available on IEEE Xplore.
In the 1960s Mr. Bushnell had worked at an amusement park and had also played space games on a PDP-10 at college. He divided the cost of a computer by the amount of money an average arcade game made and promptly dropped the idea, because the economics did not make sense.
Then in 1971 he saw a Data General computer advertised for $5000 and determined that a computer game played on six terminals hooked up to that computer could be profitable. He began designing a space game to run on such a timeshared system, but because game action occurs in real time, the computer was too slow. Mr. Bushnell began trying to take the load off the central computer by making the terminals smarter, adding a sync generator in each, then circuits to display a star field, until the computer did nothing but keep track of where the player was. Then, Mr. Bushnell said, he realized he did not need the central computer at all—the terminals could stand alone.
“He actually had the order for the computers completed, but his wife forgot to mail it,” Mr. Alcorn said, adding, “We would have been bankrupt if she had.”
Mr. Bushnell said, “The economics were not longer a $6000 computer plus all the hardware in the monitors; they became a $400 computer hooked up to a $100 monitor and put in a $100 cabinet. The ice water thawed in my veins.”
The ball in Pong is square. Considering the amount of circuitry a round ball would require, “who is going to pay an extra quarter for a round ball?”
Computer Space appealed only to sophisticated game players—those who were familiar with space games on mainframe computers, or those who frequent the arcades today. It was well before its time. Pong, on the other hand, was too simple for an EE like Mr. Bushnell to consider designing it as a real game—and that is why it was a success.
Mr. Bushnell had developed the motion circuit in his attempt to make the Computer Space terminals smarter, but Mr. Alcorn could not read his schematics and had to redesign it. Mr. Alcorn was trying to get the price down into the range of an average consumer product, which took a lot of ingenuity and some tradeoffs.
“There was no real bulk memory available in 1972,” he said. “We were faced with having a ball move into any of the spots in a 200-by-200 array without being able to store a move. We did it with about 10 off-the-shelf TTL parts by making sync generators that were set one or two lines per frame off register.”
Thus, the ball would move in relation to the screen, both vertically and horizontally, just as a misadjusted television picture may roll. Mr. Alcorn recalled that he originally used a chip from Fairchild to generate the display for the score, but it cost $5, and he could do the same thing for $3 using TTL parts, though the score was cruder.
The ball in Pong is square—another tradeoff. Considering the amount of circuitry a round ball would require, Mr. Alcorn asked, “who is going to pay an extra quarter for a round ball?”
Sound was also a point of contention at Atari. Mr. Bushnell wanted the roar of approval of a crowd of thousands; Mr. Dabney wanted the crowd booing.
“How do you do that with digital stuff?” Mr. Alcorn asked. “I told them I didn’t have enough parts to do that, so I just poked around inside the vertical sync generator for the appropriate tones and made the cheapest sound possible.”
The hardware design of Pong took three months, and Mr. Alcorn’s finished prototype had 73 ICs, which, at 50 cents a chip, added up to $30 to $40 worth of parts. “That’s a long way from a consumer product, not including the package, and I was depressed, but Noland said ‘Yeah, well, not bad.’”
They set the Pong 2 prototype up in a bar and got a call the next day to take it out because it was not working. When they arrived, the problem was obvious: the coin box was jammed full of quarters.