Computer Space and the Dawn of the Arcade Video Game

Enter Nutting Associates

nutting associates headquarters

By early 1970, Bushnell had already been brainstorming about how to turn Dabney’s video control board into a shipping game. He decided that he needed investment from an outside source to make his dream of a coin-operated video game a reality, but he had no connections in the arcade industry.

The opportunity Bushnell needed fell into his lap in February 1970 during a visit to the dentist. While getting his teeth checked out, Bushnell described his current project to the doctor, who recalled a patient of his that worked as marketing director for a local coin-op game company.

trivia quiz arcade
That patient happened to be Dave Ralston of Nutting Associates, a small arcade game maker based in Mountain View. Nutting’s marquee product at the time was Computer Quiz, a general trivia arcade machine that projected questions onto a screen and allowed users to choose answers with push button controls. (No computers were actually involved.)

Bushnell called Ralston, and two days later he was in Nutting Associates’ offices pitching to both Ralston and Bill Nutting, president of the company, on his idea for a coin-operated Spacewar game. At the time, Nutting Associates was in financial decline, almost wholly dependent on its three-year-old Computer Quiz game to get by. The pair were anxious for another product to revive their business, so they said yes to Bushnell’s idea while also extending an offer to hire him as chief engineer of Nutting.

Sensing Nutting’s desperation, Bushnell pitched an amazingly lopsided deal that allowed him and Dabney to retain the rights to Computer Space, licensing it to Nutting for production in exchange for a 5% royalty on unit sales — even though Bushnell would develop the game as an employee. Nutting would provide the facilities for Computer Space’s development and pay its manufacturing costs.

“I was very careful,” recalls Bushnell. “In my employment contract, I excluded the video game technology and all the shop right issues and told them that I would not work on the design of the video game on their time until it was ready to be put into production, which is something that I would allow them to pay for.”

Before Bushnell came along, Nutting Associates had no in-house capability to design a game for itself. Computer Quiz had been created by Bill Nutting’s brother, David, who lived in Chicago and operated his own amusements company. “They didn’t have an engineering staff,” says Dabney, “and they didn’t have anybody that understood how to fix their machines when they broke. Nolan convinced him he could do that.”

So, in a sense, Bushnell became Nutting’s engineering department when he joined Nutting in March 1970, quitting his job at Ampex without a second thought. Meanwhile, Dabney stayed behind at his old employer. He wasn’t ready to give up his secure job for a risky proposition — yet.

Bushnell, on the other hand, was convinced that video-based arcade games were the future of the arcade amusement industry. They would be solid state, having no moving parts other than the controls, so they would be easy to deploy and maintain. At Nutting, he set out to build the first coin-operated video game ever created. As it turned out, he wasn’t completely alone.

A Coincidence Six Miles Away

galaxy game

Around the time Bushnell started developing Computer Space at Nutting, a Stanford alumnus and his high school buddy had just begun work on their own coin-operated version of Spacewar. Unlike Bushnell’s version, their game would rely on a real computer to function.

In 1971, Bill Pitts and Hugh Tuck bought a $14,000 DEC PDP-11/20 minicomputer and a $3,000 vector display with money gathered from family and friends. Tuck built controls and enclosures while Pitts began programming a custom reproduction of Spacewar with the goal of creating a coin-munching pay-to-play amusement device.

With the “war” in “Spacewar” being an unpopular subject on university campuses at the time, they chose the title “Galaxy Game” to describe their work.

Just as Tuck and Pitts were finalizing their game, they received a call from Nolan Bushnell, who had heard about Galaxy Game through mutual contacts. Neither party knew of the other’s effort when they started, so Bushnell was understandably intrigued.

“I can remember thinking ‘Gee, I’ve got to meet with these guys,’” recalls Bushnell. Over coffee at Stanford, the Nutting engineer told Galaxy Game’s creators about his plans for Computer Space and invited them over to Nutting’s offices to take a look.

“We went in there and Nolan was literally an engineer with an oscilloscope in hand working on Computer Space,” said Pitts in an interview with Tristan Donovan for the book Replay: The History of Video Games. Pitts and Tuck were impressed with what Bushnell was pulling off technologically, but they felt their game was superior because it was true to Spacewar.

Bushnell, who was sizing up potential competition, felt relieved when he learned that the pair had not unlocked any secret recipe that would allow a computer-based arcade game to thrive in the 1971 coin-op market. At over $17,000 per machine, just for parts, Galaxy Game had no ability to scale to the point where it could appear in more than one or a few locations. It would have required too much up front cost, too much maintenance, and too much time for the payout in coins to even equal the cost of the equipment involved.

When Galaxy Game made it debut at the Tresidder Memorial Union, a student community building on Stanford’s campus, the intense space simulation attracted a sizable crowd of fans, some of whom would wait hours for their chance to play. Tuck and Pitts charged 10 cents a game or a quarter for three games, with a free game going to the winner.

Galaxy Game did well enough that the duo created a second version of the game a year later (interestingly, that version could support multiple games on a single machine like Bushnell had originally planned), but the high cost of the hardware prevented the idea from going any further. “They were kind of funny guys that were technical, but not real focused on world domination,” says Bushnell. That was fine with Tuck and Pitts, who seemed content to merely dominate a single building at Stanford.

So how did both Bushnell and the Stanford duo hit upon the same idea almost simultaneously (and only six miles apart)? If history is any indication, commonly-available advances in technology tend to make certain innovations so obvious that it would be amazing if they didn’t happen. It then becomes a case of when, not if, such an invention will develop.

It’s rare that only one person invents an idea without another independently doing so shortly afterward. It had happened before with Bushnell (although he didn’t know it at the time), who wasn’t the first to invent television video games. Ralph Baer had beat him to it by a mere three years. Bushnell was, however, the first to make them work in a commercial arcade setting. But not before putting in a half-year of intense work that began when he walked into Nutting’s office on his first day as chief engineer.

Bushnell’s Rotating Rocket

Bushnell rotating rocket design

With Ted Dabney’s video control board in hand, Bushnell set out to create his own interpretation of Spacewar at Nutting’s modest headquarters in Mountain View. Bushnell’s contribution to the game was somewhat analogous to those of both game designer and programmer today. Dabney had created a basic board that could put spots on a TV screen and could move them around (a system); Bushnell would design circuitry that would decide what spots to put on the screen, where, and how they would interact and respond to controls (the program).

Of course, there was no computer system or software involved. Bushnell would render his electronic game logic in hardware using medium-scale integration ICs, transistors, and diodes. It wasn’t easy.

In an era long before computer-aided design (CAD) tools existed, Bushnell spent most of his working hours at a drafting table located just outside his office door at Nutting. He utilized common engineering stencils to draw diagrams and schematics in pencil on C-size vellum. “I spent more time there than I ever did sitting in my office chair,” recalls Bushnell. He worked long hours–usually from 8 AM to midnight–in a furious push to finish his new game before a large amusement trade show in October 1971.

While Bushnell worked on the logic circuitry, Dabney visited Nutting’s offices at night to craft other aspects of the game’s hardware system, including the power supply, coin mechanism, control panel, and the sound generating circuitry. He also built the game’s prototype cabinet, a simple wooden upright-oriented box that looked similar to the Pong cabinet that he would design a year later.

Bushnell wanted his Syzygy partner to join Nutting, and Dabney still resisted. But by mid-1970, Bushnell had made such impressive progress on the game that Dabney reconsidered his position. “I was still working at Ampex,” recalls Dabney, “and I’d come in after work and see what was going on. I was blown away by what Nolan was able to accomplish. It was fantastic.” Dabney finally gave in and joined Nutting full time in the summer of that year.

According to Dabney, Bushnell’s greatest personal design triumph involved the on-screen rotation of the rocket ship, which was composed of an outline of dots with small gaps between them. “One of the hardest things to do was to get the rocket ship to actually rotate,” says Dabney. “That was a very, very difficult thing to work out.” But Bushnell did figure it out, and he says his solution is the aspect of Computer Space’s design he is most proud of.

rom chips
ROM chips, the read-only integrated circuits that store digital data, were very expensive in 1971. To manufacture them inexpensively, per unit, required mass production runs to the order of thousands of chips, which was not something Nutting would have invested in for a limited-run arcade unit. So Bushnell electronically stored the shape of the rocket ship and saucer using the most basic form of read-only memory available: discrete diodes on a circuit board, which he whimsically laid out to resemble the actual shapes they represented on the screen.

In other words, if you look at the production Computer Space “memory board” (as it is labeled), you will see the outline of the on-screen rocket ship and the saucer represented as diodes soldered in place. To keep things simple and inexpensive, Bushnell wanted to have as few of these images as possible on the board.

In order to produce a fluid rotation animation, Bushnell wanted as many as 16 directions that the rocket could point. He came up with a way to do that using four images of the rocket that could be mirrored, each one being flipped once on its X-axis and Y-axis.

He then realized that an image of the rocket ship pointing straight up, when mirrored left-to-right, would result in the exact same image, so he settled on four representations of the rocket ship at different angles. “The first one was tilted just about five degrees off vertical,” recalls Bushnell, “so when I folded it, the next image was pointing 10 degrees in the other direction.” His clever scheme produced a surprisingly smooth rocket rotation for a video game created in 1971.

Bushnell also managed to implement apparently complex machine-controlled behavior of the player’s foes using a simple procedure. The two flying saucers, the target of the player’s fire, would merely detect which quadrant of the screen hosted the player’s rocket ship and it fire in that direction. “It was a total cheat,” says Bushnell of the approach, but the world’s first video game AI worked well given the technological limitations.

When he was finished, Bushnell’s logic boards appeared stunningly well-engineered to Dabney, who today raises the possibility that Bushnell received significant help with the design from his former colleagues at Ampex, especially Steve Bristow, who later joined Atari. Bushnell and Bristow both deny this. “I did none of the design work, but was involved in the construction of prototypes,” Bristow told me in a recent e-mail. For his part, Bushnell doesn’t recall Bristow being involved in the project at all: “I was the logic engineer, pure and simple.” Confusion may have arisen on Dabney’s part because Bristow engineered a later two-player version of Computer Space for Nutting.

Regarding who gets credit for what work, it is worth noting that Bushnell filed a US patent (No. 3793483) in 1972 that covered Dabney’s invention of the Computer Space video control circuitry–not the logic circuitry Bushnell created. Dabney is not listed as an inventor on the patent, which was awarded solely to Bushnell in 1974. Dabney was never aware of the patent until recently, though the fact that Bushnell didn’t include his name on the patent doesn’t keep Dabney up at night. “Nolan would never share something like that with me,” he says. “That’s just the way he did business.”

Next: The Finishing Touches

Subscribe to the Daily Downloads Newsletter