If you spend any time around technology, and probably even if you don’t, then you’ll probably also have heard some variation on the saying “There’s more computing power in your pocket than was used to send humans to the moon.” It’s true, of course. The chip in the recently announced iPhone XS runs about five million times faster than the Apollo Guidance Computer. But the axiom has been true for rather longer than most people realize.

The other day, I stumbled across a wonderful Twitter thread that talked about the “Great Calculator Race” of the 1970s and detailed some of the wonderful, wacky designs manufacturers unleashed upon the world. The first computing device that would actually fit in your pocket (a man’s pocket, that is) was the Cal Tech, a 1967 prototype created by Texas Instruments, although like many of the earliest pocket calculators it still required an AC power lead to work rather than batteries. It was black, boxy, and incredibly sleek compared to expensive, desk-mounted calculators like the chunky Casio Model 14-A.

Wikimedia Commons/Daderot/CC0 1.0 Casio’s 1957 Model 14-A, a typical example of a calculator at the time.

In 1969, while humans were wandering around on the moon, technology companies were already working on making slimmer, faster calculators, like Sharp’s 1970 QT-8B Micro Compet. It was the first mass-produced battery-powered pocket calculator, with red, white, and blue buttons and a hooded vacuum tube display; Hewlett-Packard’s 1971 HP-35, with a bright red display and 35 yellow and blue keys, was even faster. Its microprocessor was capable of performing trigonometric and exponential functions. It was the first pocket scientific calculator, and killed the slide rule stone-dead, but it wasn’t yet a match for the Apollo Guidance Computer—it was about 200 times slower.

The successor to the HP-35, the HP-65, was even more ambitious: it used magnetic cards to “save” and “load” programs, and supported up to 100 lines of code. It came with algorithms for hundreds of different applications—differential equations, stock prices, statistics, and more. The bottom was tapered thinner than the top, too, to better fit into a shirt pocket.

Wikimedia Commons/Mister rf/CC BY-SA 4.0 Sharp’s QT-8B Micro Compet from 1970, the first battery-powered pocket calculator, pictured here in its charging dock.

The HP-65 was also the first programmable pocket calculator in space, taken aboard the 1975 Apollo-Soyuz Test Project, a groundbreaking US-Russian collaboration that arguably marked the end of the space race. The HP-65 was there as backup, in case of problems with the Apollo Guidance Computer. Just six years after Michael Collins, Buzz Aldrin, and Neil Armstrong’s historic mission, a calculator was already judged capable enough to fill in for the hardware that took them to the moon.

The HP-65 marked the start of a new era, as silicon chips became cheap and ubiquitous. The Speak & Spell, which Texas Instruments released in 1978, wasn’t just an iconic toy—it had a third of the processing power of the Apollo Guidance Computer, and cost just $50 (about $191 today). Through the 1970s and into the 1980s, the Great Calculator Race turned into the pocket computer boom, and devices gained more and more features: by 1979, you could accessorize a calculator like the HP-41C with extras such as a barcode reader, a floppy disk drive, and a printer. The device even came along on nine early space shuttle missions to perform basic calculations and serve as a backup to the main onboard computer.

Wikimedia Commons/FozzTexx/CC BY-SA 4.0 Texas Instruments’s Speak & Spell, released in 1978.

The Soviet Union had its own parallel programmable calculator industry in the late 1970s, beginning with 1978’s garish, plasticky Elektronika B3–21 and followed by the equally cheap-looking Elektronika B3–34, released in 1980 and sold for 85 rubles (about $35, or $107 in 2018 adjusted for inflation, although historical currency conversions across the Iron Curtain should always be taken with a pinch of salt). This was the first computer many people in the USSR ever used, and they wrote all kinds of programs for it—from scientific and business software to adventure games. In 1985, the science magazine Tekhnika Molodezhi published a science fiction story named “Way to Earth,” accompanied by programs for the B3–34 that could be used to simulate the story’s journey from the moon to the Earth. The calculator sent humans to the moon in fiction, if not fact.

One thing the Elektronika series of calculators was known for was “еггогология,” or “errorology.” If you deliberately generated an error message, then entered specific commands, you could get into otherwise inaccessible parts of the code. Probing the innards of these calculators helped Soviet programmers develop their skills, and many of Russia’s older hackers may well have started their careers with a B3–34.

The term “pocket computer” originated in 1980 with the metal-encased, businesslike Sharp PC-1211—which was branded in the US as the TRS-80 Pocket Computer. It used the BASIC programming language, had a full QWERTY keyboard and number pad, and could emit irritating noises. I remember that my father owned a much-loved later model in this series, which he called “Herbie.” My siblings and I found it when we were clearing out his house last year, but we decided not to save it—I prefer to keep Herbie alive in my mind, rather than in a dusty drawer.

Over the course of the 1980s, these types of pocket computers became increasingly powerful. In 1984, the British company Psion launched the Psion Organiser I as the “world’s first practical pocket computer”—and, 15 years after the first moon landing, this machine’s processor was as fast as the Apollo Guidance Computer. The Psion Organiser II, released in 1986, even had what we’d today call apps—it had a database, a diary, and an alarm clock, and could be extended yet further using programs written by the user. The Organiser II was widely used—by staff in the British department store chain Marks & Spencer, for example, and by UK government officials who calculated people’s employment benefits. These devices were full-fledged computers, no longer mere calculators.

Wikimedia Commons/Snowmanradio/CC BY-SA 2.5 Psion’s 1986 Organiser II.

In a March 26, 1981, New York Times article, Andrew Pollack surveyed the landscape of “The Portable Computer.” He marveled at a $250 computer small enough to fit in a coat pocket, and quoted Portia Isaacson of Future Computing, a Dallas-area consulting firm, who predicted that “portable computers will take off like gangbusters.” She told Pollack that businessmen would soon “be able to dictate letters, type and edit reports, have access to company files and send data to the main company computer while on the road.” Isaacson’s name for this device? “The Swiss Army Pocket Computer.”

Of course, to send information back to the office from the road, a computer needs a way to transmit data wirelessly. At the dawn of the 1990s, pocket computers still used bulky, proprietary ports to send data over cables. For example, the Sharp Wizard OZ-7000, a gray plastic pocket organizer, could connect to a Windows PC, a Macintosh, or a printer, and could even back up data to cassette tapes. By this point, these kinds of devices were a common sight in the cities of the developed world—the Wizard even later starred in its own episode of Seinfeld, though it was dismissed as merely a “tip calculator.”

It was only a matter of time before pocket computers merged with telephones, as foreshadowed by a revolution underway elsewhere. In 1990, Tim Berners-Lee wrote the first web browser while at CERN, and it was publicly available a year later. The World Wide Web had arrived.

Sharp An ad for the 1989 Sharp Wizard OZ-7000, including accessories.

Soon, the market for pocket computing was cleaving in two. On one side were essentially pocket laptops, increasingly capable and powerful machines that became known as “palmtop computers.” This group included the world’s first palmtop, the boxy Atari Portfolio. It was originally sold as the DIP Pocket PC in the UK, before Atari bought the rights to the device—and it made a cameo appearance in Terminator 2: Judgement Day, where it was used to hack into an ATM. There was also the sleeker HP 95LX, which could communicate via infrared. The Poqet PC could even run MS-DOS, but would stop its CPU between keystrokes to save power.

On the other side were devices that hid complexity from the user, such as Casio’s Digital Diary series. Instead of attempting to offer tiny programmable desktop PCs, manufacturers preloaded these machines with simple software tools like calendars, address books, and alarm clocks. The Sharp Wizard, the “tip calculator” from Seinfeld, was one of these.

The most beloved pocket computer of the nineties, though, was the Psion Series 3, which fell between the two pocket computing categories. Technology writer Charles Stross has eulogized the device’s “omnicompetent brilliance,” praising it as “a real computer that did just about everything you expected of a desktop in those days and which you could stick in your pocket.” Released in 1991, the Series 3 came preloaded with software, but it also let users create their own programs. People traded these “shareware” programs across the nascent internet, and many are still available to this day.

Apple An ad for Apple’s 1992 Newton MessagePad, boasting about its versatility.

In January, 1992, Apple Computer CEO John Sculley announced the Apple Newton MessagePad—and coined the phrase “personal digital assistant.” But the Newton’s innovations, which included handwriting recognition and a touchscreen, weren’t enough to outweigh its high price and poor performance. Ultimately, its only lasting legacy was the term “PDA”—a designation that soon became obsolete, as PDAs morphed into modern smartphones.

Only a few months after Apple announced the Newton, IBM presented its own prototype PDA—code-named “Angler”—at the COMDEX trade fair in Las Vegas. In addition to boasting a calendar, an address book, a notepad, a touchscreen, and rechargeable batteries, the device also had the ability to send and receive calls, faxes, emails, and pages. Angler became the IBM Simon, released in 1994; it was, arguably, the first smartphone, and the term “smartphone” was itself coined only a year later by Bell Labs’ Pamela Savage.

Bcos47/Public Domain IBM’s Simon, “the first smartphone.”

By the mid-to-late 1990s, the smartphone was clearly the pocket computer of the future. However, it took longer for manufacturers to perfect the form factor, and for mobile internet speeds to get fast enough for constant data connectivity. The 1996 Nokia 9000 Communicator, for example, came with a 9.6 kbit/s modem, a web browser, and business software that included word processors and spreadsheets. At launch, it cost £1,000 ($1,300) in the UK—the same sticker price as the iPhone X when it was released more than 20 years later—but the user still had to manually dial-up for web access. The Communicator was a success in Europe, but due to technical disagreements between Nokia and US carriers, it never took off across the Atlantic—Americans had to wait until 1998 for the smartphone revolution to arrive, in the form of Qualcomm’s pdQ Smartphone, a PDA that could also make calls.

In the meantime, the US market had the PalmPilot to play with. Palm was an American company that released a series of much-loved PDAs in the mid-to late-1990s, complete with a well-designed operating system called PalmOS. Their most notable feature was Graffiti—a single-stroke form of shorthand that allowed users to write quickly using a stylus, after taking the time to learn the necessary glyphs. Even today, you can find people requesting Graffiti support for iOS and Android.

Around the same time as all of this, Steve Jobs returned to Apple after more than a decade away from the company. He cancelled the Newton line entirely. “My gut was that there was some really good technology, but it was fucked up by mismanagement,” he later told biographer Walter Isaacson. “By shutting it down, I freed up some good engineers who could work on new mobile devices.” Meanwhile, the svelte Ericsson R380, released in November 2000, was the first touchscreen smartphone to be the same size and weight as a regular cellphone.

The early 2000s saw different companies around the world gradually take control of their regional smartphone markets. Japanese firm NTT DoCoMo’s range of cheap internet-enabled phones gave them 40 million subscribers by the end of 2001. Nokia’s Symbian platform became dominant in Europe, while in the US Microsoft’s Windows Mobile and Research in Motion’s BlackBerry smartphone were the two main contenders, with the BlackBerry also especially popular with the international business sector for several years.

This didn’t stop some companies from attempting to build a breakout device that could appeal to the whole world—like the dead-end Danger Hiptop line (known in the US as the T-Mobile Sidekick). LG came close to achieving that goal with its 2006 Prada handset, which won multiple design awards. The device was slim, with a large touchscreen. It looked exactly like a smartphone as we know them today.

Except, of course, it wasn’t the smartphone. On January 9, 2007, Steve Jobs stepped onto a stage at the Macworld Conference & Expo in California and made pocket computing history.

“Today,” he said, “Apple is going to reinvent the phone.”

This article was originally published on How We Get To Next, under a CC BY-SA 4.0 license. Read more about republishing How We Get To Next articles. Sign up to the How We Get To Next newsletter here.