Despite the passage of time, Gates still cherishes the groundbreaking code he printed on a teletype machine—a piece of work that, though rudimentary compared to modern artificial intelligence, played a crucial role in launching Microsoft in April 1975. The company, headquartered in Redmond, Washington, marks its 50th anniversary on Friday.
In a blog post, the 69-year-old Gates reminisced about how he and his late high school friend, Paul Allen, embarked on a mission to build the world’s first “software factory.” Their journey began after reading a January 1975 Popular Electronics article about the Altair 8800, an early minicomputer powered by a small chip from Intel, which was relatively unknown at the time.
Inspired by the article, Gates—then a freshman at Harvard—and Allen contacted Micro Instrumentation and Telemetry Systems (MITS), the company behind Altair. They assured its CEO, Ed Roberts, that they had developed software to operate the hardware. However, there was one major problem: the code they promised had yet to be written.
To meet the challenge, the duo turned to BASIC, a programming language created at Dartmouth College in 1964. They had to make it compatible with the Altair despite not having a prototype of the machine. After two months of intense work and little sleep, Gates completed the program, which became the Altair’s first operating system.
“That code remains the coolest I’ve ever written,” Gates noted in his blog post, which also includes an option to download the original program.
This code laid the foundation for a company that revolutionized personal computing, introducing software like Word, Excel, and PowerPoint, as well as the Windows operating system, which continues to dominate the PC market.
“That was the revolution,” Gates said in an accompanying video. “That was the moment that brought personal computing to life.”
Gates’ reflection on this milestone is part of a broader wave of nostalgia as he approaches his 70th birthday in October. This year, he released a memoir detailing his early life as a misunderstood child with few friends. He also marked the 25th anniversary of the philanthropic foundation he established after stepping down as Microsoft’s CEO in 2000. While Microsoft initially struggled post-Gates, it has flourished under current CEO Satya Nadella, now boasting a market value of around $2.8 trillion.
In his memoir, Gates also revisited his complex relationship with Apple’s late co-founder Steve Jobs, whose company will celebrate its 50th anniversary next year.
“Fifty years is a long time,” Gates reflected. “It’s incredible that the dream became a reality.”