Bill Gates Reflects on the Code That Sparked Microsoft’s Revolution – 50 Years Later

As Microsoft approaches its golden anniversary, founder Bill Gates is taking a poignant journey down memory lane—one that stretches back to a pivotal moment in tech history. In a recent blog post marking 50 years since Microsoft’s inception in April 1975, Gates recalls the original computer code he wrote that would become the catalyst for one of the world’s most influential technology companies.

Despite the passage of time and the massive advancements in computing, Gates, now 69, still holds a deep affection for the program he developed alongside his late friend and Microsoft co-founder Paul Allen. “That code remains the coolest I’ve ever written,” Gates writes. It wasn’t just the foundation of Microsoft—it was the start of the personal computing revolution.

A Code That Changed Everything

The story begins with an article in the January 1975 issue of Popular Electronics that introduced the Altair 8800, an early minicomputer powered by a tiny Intel chip. Gates, then a freshman at Harvard University, and Allen, already passionate about computing, immediately saw the potential. Inspired, they reached out to Altair's maker, Micro Instrumentation and Telemetry Systems (MITS), and told CEO Ed Roberts they had created a software program that could run on the Altair.

There was just one problem—they hadn’t written the software yet.

What followed was an intense, sleep-deprived two-month coding marathon. With only the BASIC language developed at Dartmouth in 1964 as their base, Gates and Allen had to make their software compatible with the Altair—without ever having access to the physical machine.

Somehow, they pulled it off. Gates wrote the code that made the Altair usable by hobbyists and early tech adopters. “That was the revolution,” Gates says in a new video accompanying his blog. “That was the thing that ushered in personal computing.”

The program they built—Altair BASIC—became Microsoft’s first product, and it opened the doors to a future few could have imagined.

The Dawn of a Tech Empire

From that humble teletype-printed code, Microsoft would grow into a global behemoth. Its operating systems—first MS-DOS and later Windows—would dominate the PC market. Office programs like Word, Excel, and PowerPoint would become workplace essentials. The software giant, once run from a small Albuquerque office, is now valued at around $2.8 trillion.

Gates stepped down as Microsoft’s CEO in 2000, shifting his focus to philanthropy through the Bill & Melinda Gates Foundation. Under the leadership of Satya Nadella since 2014, Microsoft has not only recovered from earlier missteps but thrived, becoming a major player in cloud computing and AI.

But for Gates, the memories of that early triumph remain vivid—and surprisingly emotional. As he prepares to turn 70 in October, the nostalgia has become a theme of his year. In February, he released a memoir reflecting on his childhood, his early fascination with computers, and his complex friendship with Apple co-founder Steve Jobs.

A Personal Milestone, A Shared Legacy

The original BASIC code, still available to download from Gates’ blog, may seem primitive today. Yet, its importance cannot be overstated. It marked the beginning of a new era, democratising computing and laying the groundwork for today's digital age.

Looking back, Gates acknowledges the extraordinary journey. “Fifty years is a long time,” he says. “It’s crazy that the dream came true.”

While today’s tech world is dominated by AI, quantum computing, and automation, it all began with a teenager typing away on a teletype machine, chasing a dream. The 50th anniversary of Microsoft is not just a celebration of corporate success—it's a tribute to the ingenuity, grit, and sheer belief that two young men had in the power of software.

And for Gates, that first program will always hold a special place in his heart—as the spark that ignited a revolution.

Conclusion

As Microsoft marks its 50th anniversary, Bill Gates’ reflection on the humble beginnings of the tech empire is a powerful reminder of how innovation often starts with a bold idea and a few lines of code. What began as a sleepless two-month sprint to build software for an unknown computer became the launchpad for one of the most influential companies in history. Gates’ journey — from a Harvard dropout tinkering with BASIC to a global icon shaping personal computing — continues to inspire generations of developers, entrepreneurs, and dreamers. His nostalgic tribute is not just about honouring the past, but also a call to future tech pioneers: the next revolution might begin with just one idea and the courage to pursue it.