The Apple II was designed by Steve Wozniak, who co-founded Apple with his friend Steve Jobs in 1976. The computer was a successor to the Apple-1, a raw motherboard best suited to the computer hobbyist community Wozniak and Jobs were a part of. With the Apple II, the pair wanted to transition into the consumer market, selling a computer that could be used by someone without an abundance of tech experience. Thus, the Apple II was built with a fixed plastic case that held a power supply and keyboard, so as to function straight out of the box. With this, the blueprint of consumer-grade computers was set, redefining the market.

The computer used a 8-bit MOS 6502 microprocessor, an advancement of the previous Motorola 6800. It boasted color graphics, seven expansion slots, BASIC built right in, and a hookup to directly connect to a television monitor. Wozniak and Jobs both wanted a computer that could be an all-in-one experience, but unlike the PET 2001 and the TRS-80, Apple II was built with open architecture, allowing the easy creation of third-party software. One such software, VisiCalc, became the very first consumer-grade spreadsheet software. The computer’s accessibility and cheap price made it very popular among educators, who incorporated it into their classrooms.

Wozniak and Jobs debuted the Apple II at the first annual West Coast Computer Faire in San Francisco. Always with an eye for image, Jobs secured an expensive booth for a hefty $5,000 and had a Plexiglass sign show off the company’s name and new logo. During the convention, Jobs met Toshio Mizushima, a Japanese businessman, and inked a deal for Mizushima to sell Apple products in Japan. What had been a garage-based company the year before was set to become a worldwide phenomenon.

Prices on the Apple II varied, beginning at $790 for 4 kilobytes of RAM. It sold very well, with production doubling every three months through the rest of 1977, and it continued manufacturing for the next 15 years, firmly establishing Apple as the go-to personal computer company. It launched the Apple II series, whose descendants incorporated better graphics, 16-bit processors, and other advancements. It also laid the groundwork for Apple’s other computers, like the Lisa and the Macintosh. Of course the Apple II now pales in comparison to the generations of computers it spawned, but its innovations stand as great leaps forward in the history of computers.

It was Wozniak who primarily designed and built the Apple II, with minimal involvement from Jobs. For all his brilliance as a businessman and trend setter, Jobs’ skill as an engineer paled in comparison to his friend. That said, Jobs can be credited for his focus on the customer experience, with the Apple II embodying the credo that the computer would include all necessary components from the jump and could be used by a layman. Like all savvy businessmen, Jobs knew to surround himself with talented people like Wozniak. One man knew how to build computers, the other knew how to sell them, and the Apple II sold very well.

With the Apple II, the Apple Company outsold its other small company competitors, but faced stiff competition from IBM’s PC. The Macintosh, built to take on this monolithic giant, ran slow and sold even slower, eventually leading to Jobs being forced out of the company in 1985. Wozniak also left around then, who by that point was not heavily involved in the company, after surviving a plane crash a few years before. Before Job’s return to the company in the late 1990s, the Apple II stood as the company’s only unambiguous success story, a machine that brought computers into the homes of the average person.

Want to read more about Steve Jobs and what came next after the Apple II? Check out INVENTING THE FUTURE: STEVE JOBS AND APPLE