The Altair 8800 launched personal computing in January 1975

The Altair 8800, released in January 1975, is widely recognized as the first personal computer. It was built by Micro Instrumentation and Telemetry Systems (MITS) in Albuquerque, New Mexico, and cost $397 for the kit version. The machine used an Intel 8080 processor, came with 256 bytes of memory (not megabytes or gigabytes), and had no keyboard, monitor, or disk drive. Users entered programs by flipping switches on the front panel and read results from blinking lights.

The Altair appeared on the cover of Popular Electronics magazine in February 1975, and the response was when ready. Thousands of people ordered kits. The machine proved that a computer small enough to fit on a desk and affordable enough for hobbyists could exist. Before the Altair, computers were room-sized machines that cost tens of thousands of dollars and belonged only to universities, corporations, and government agencies.

What made the Altair truly significant was not its power—it could barely do anything by modern standards—but that it created a market. The success of the Altair attracted other manufacturers and sparked the personal computer revolution that followed.

Key Takeaways

  • The Altair 8800, released in January 1975, is the first widely recognized personal computer, built by MITS and costing $397 for a kit.
  • The Altair had 256 bytes of memory, no keyboard or monitor, and required users to input programs by flipping physical switches on its front panel.
  • The machine's appearance in Popular Electronics magazine created when ready demand and proved that affordable, desk-sized computers could reach consumers.
  • Before the Altair, computers were large, expensive machines found only in institutions; the Altair opened the door to home and hobbyist computing.

Earlier machines that came close but didn't reach consumers

Several computers built before 1975 had some of the characteristics we associate with personal machines, but none reached the public market. The ENIAC, completed in 1946, was the first general-purpose electronic computer, but it weighed 30 tons and occupied 1,800 square feet. The Apple I, built by Steve Jobs and Steve Wozniak in 1976, came a year after the Altair and was the first computer sold as a fully assembled unit rather than a kit—but it arrived after the Altair had already defined the category.

The IBM PC, released in August 1981, was not the first personal computer, but it became the most influential. IBM's entry into the market legitimized personal computing for businesses and established the architecture that most computers still follow today. However, the Altair had already proven the concept six years earlier.

Why the Altair mattered more than its specs suggest

The Altair's technical limitations were severe. It could not run useful programs without additional hardware and software that cost extra money and required technical knowledge to install. Most owners never did anything practical with their machines—they were hobbyists who enjoyed building and experimenting.

What mattered was that the Altair created a community. Hobbyists formed clubs, shared code, and built add-ons. The Homebrew Computer Club in California, where Jobs and Wozniak met, grew directly from the excitement around the Altair. This community produced the software and innovations that made later computers actually useful. Without the Altair's market success, the personal computer industry might have developed very differently—or not at all.

The timeline from Altair to machines people actually used

The jump from the Altair in 1975 to computers that ordinary people could use took about five years. The Apple II, released in 1977, came with a keyboard, color graphics, and a disk drive, making it the first personal computer that felt complete out of the box. The Commodore 64, released in 1982, became the best-selling computer of the 1980s because it was affordable and came with games and educational software built in.

The IBM PC's open architecture meant that many manufacturers could build compatible machines, which drove prices down and created competition. By the mid-1980s, personal computers were becoming common in homes and small offices. The machines went from hobbyist kits to consumer products in less than a decade.

What "first personal computer" actually means

The title "first personal computer" depends on how you define the term. If you mean the first computer designed for individual use and sold to consumers, the Altair 8800 holds that place. If you mean the first computer that was actually practical for non-technical users, that would be the Apple II or Commodore 64. If you mean the first computer that shaped the industry as it exists today, the IBM PC is the answer.

Historians and engineers sometimes point to earlier machines like the Programma 101, built by Olivetti in Italy in 1965, as a precursor to personal computing. The Programma 101 was a desktop calculator that could store and run programs, and it was sold to consumers. However, it was marketed as a calculator, not a computer, and it never reached a mass market. The Altair, by contrast, was explicitly marketed as a computer and created the category that everything else followed.

How the Altair's design influenced computers that came after

The Altair established several patterns that personal computers followed for decades. It used an open architecture, meaning other companies could build add-on cards and peripherals that plugged into the main machine. This openness encouraged third-party developers to create software and hardware, which made the platform more valuable. The IBM PC copied this approach, and it became the standard for the industry.

The Altair also proved that consumers would buy computers as kits and assemble them themselves, at least initially. This kit model lowered the barrier to entry and attracted hobbyists who might not have bought a finished product. As the market matured, manufacturers moved toward selling fully assembled machines, but the kit model had served its purpose in building the early community.

Frequently Asked Questions

Was the Apple I the first personal computer?

No. The Apple I, released in 1976, came a year after the Altair 8800. However, the Apple I was the first personal computer sold as a fully assembled unit rather than a kit. The Altair arrived first and created the market that Apple entered.

Did the IBM PC come before the Altair?

No. The IBM PC was released in 1981, six years after the Altair 8800. The IBM PC became the most influential personal computer and shaped the industry as it exists today, but it was not the first.

Could the Altair actually do anything useful?

Not much, by itself. The Altair had no keyboard, monitor, or storage, and only 256 bytes of memory. Users entered programs by flipping switches and read results from blinking lights. Most owners were hobbyists who enjoyed building and experimenting rather than using the machine for practical work.

Why did the Altair succeed when earlier computers didn't reach consumers?

The Altair was affordable, small enough to fit on a desk, and marketed directly to hobbyists through Popular Electronics magazine. Earlier computers were room-sized machines that cost tens of thousands of dollars and were sold only to institutions. The Altair proved that a market existed for personal computers.

What happened to MITS after the Altair?

MITS was acquired by Pertec Computer Corporation in 1977, just two years after the Altair's release. By then, other manufacturers had entered the personal computer market, and the Altair's dominance had faded. However, MITS had already accomplished its historical role: proving that personal computers could exist and that people wanted them.