Forty years ago, on August 12, 1981, IBM announced the birth of the model 5150, IBM’s first PC (see above). That first IBM PC had a dominant role in liberating the business world from its basement mainframes while making computing more available in homes with affordable desktops.

On August 25, 1991, a Helsinki student, Linus Torvalds, sent a notice to the comp.os.minix Usenet bulletin board that he was “working on a (free) operating system for 386 (486) AT clones [PCs that are IBM compatible].” Today, according to The Register, Torvalds’s hobby operating system, Linux, dominates “the supercomputer world with 100 per cent market share of the Top500…. [and] is at the heart of more than three billion active devices running Android, the most-used operating system in the world.”

These two revolutions in August didn’t represent moments of genesis because desktops and operating systems like UNIX and DOS were already available. Rather, IBM’s new hardware and Torvalds’s free operating system proved to be significant accelerants for developments going forward.


When Don Estridge’s team in Boca Raton, Fla., in the United States released its version of the IBM PC in August 1981, the personal computer market was already controlled by Tandy Corporation (RadioShack), Osborne, Commodore, and Apple, all of which offered machines for the home for several hundred dollars. But the desktop market was very tempting for Big Blue, having reached $15 billion in annual sales by 1979 and sustaining a 40% growth rate in the early 1980s.

The move by the corporate giant into their territory should have created panic among the much smaller computer companies, but at Apple, Steve Jobs responded to the news with a full-page ad in The Wall Street Journal, a smirking display of his audacity. He welcomed IBM, encouraging them in their efforts to catch up. The congratulatory taunt ran in the Saturday paper, August 22, 1981.

The 5150 had two floppy disks for memory, ranging from 16KB to 640KB, an Intel 8088 CPU, IBM BASIC/PC DOS 1.0 operating system, a monochrome monitor, a keyboard, and a single speaker. It started at $1,565. The Apple engineers weren’t very impressed when they finally got their hands on one and took it apart. Yet, despite the price and the uninspired engineering, the IBM PC came to dominate for several important reasons.

First, there was the corporate and marketing might of IBM dedicated to making it a success, and second, the architecture was open. Wikipedia notes that “a substantial market of third-party peripherals, expansion cards and software grew up rapidly to support it…. The specifications of the IBM PC became one of the most popular computer design standards in the world, and the only significant competition it faced from a non-compatible platform throughout the 1980s was from the Apple Macintosh product line.” As a result, “The majority of modern personal computers are distant descendants of the IBM PC.”

IBM didn’t have retail outlets for this kind of computer, so they partnered with Sears, Roebuck & Co. and the ComputerLand chains, and they created a television ad campaign featuring a version of Charlie Chaplin’s Little Tramp.

Click the image to view the series of Chaplin PC ads which tracks the early history of the PC including XTs and PC Juniors.

The popularity of their new PC initially overwhelmed IBM’s ability to fulfill orders. By 1983, they were selling 750,000 units annually, and the software being written to support the machines exploded. InfoWorld counted 753 software packages available a year after the IBM PC was released, and within a year, there were 30 to 40 companies selling memory expansion cards for the computer.

By 1984, the revenue for IBM PCs was $4 billion, and the PC compatible clones were establishing a parallel market with the first released in June of 1982, less than a year after the debut of the IBM PC. The penetration in the business world was also flourishing. A survey done by Fortune in 1985 revealed that 56% of American companies chose IBM PCs compared to Apple’s 16%. Welcome indeed!


In 1991, Linus Torvalds was annoyed at the limitations of the MINIX operating system he was using for school, so he wrote his own system, which became the Linux kernel. He made the code available to other developers who wanted to contribute, and, shortly, Linux became a fully functional and free operating system.

The original Linux logo

Today, it’s the most used operating system in the world, driving supercomputers, netbooks, Kindle e-readers, social media, and smartwatches. NASA’s Pleiades supercomputer runs Linux, and the International Space Station switched from Windows to Linux six years ago. Here on Earth, Amazon’s assistant, Alexa, is powered by an Android-based operating system using Linux, and the Roku operating system for TV has a custom version of it.

The Library of Congress and the White House use Linux, and so does the New York Stock Exchange. Stephen Vaughan-Nichols writing for ZDNet summed up the trajectory for the hobby operating system: “Thirty years later, Linux rules IT. Almost all major websites—including Google, Facebook, and Wikipedia—run on Linux. It’s the same with the clouds…. Thanks to Android, Linux is also the most popular end-user operating system. Not bad for a hobby operating system!”

The reasons for this rapid and varied expansion comes down to two essential conditions. First, Linux is free software that you’re allowed to use and even change to accommodate your own requirements. Over the 30 years, the many distributions (versions) of Linux evolved in the hands of numerous developers and user communities. “In many cities and regions, local associations known as Linux User Groups (LUGs) seek to promote their preferred distribution and by extension free software. They hold meetings and provide free demonstrations, training, technical support, and operating system installation to new users” (Wikipedia).

At 51, Torvalds was recently asked about his future involvement as the central administrator for Linux, and he replied that he isn’t yet ready to retire quietly to the garden. Among new developments for his operating system, recent reports have described IBM’s efforts to port a version of Linux for use in its quantum computers.

As the two birthdates rolled by at the end of last month, there was noticeably more public celebration at Linux worldwide. IBM is no longer offering PCs, so the celebration there was subdued. But looking back over these two epic computer developments, a question that naturally arises is, where would we be today without the IBM PC and Torvalds’s Linux? Likely, not anywhere near where we have gotten to.

About the Authors