Paul Gardner Allen

On the final descent into Albuquerque, Allen realized that the BASIC interpreter he was about to demonstrate had no bootloader, and wrote one by hand in 8080 machine code on a steno pad. He had built and tested the program on an emulator he wrote himself, never on the machine it was written for, and the demonstration succeeded.¹ Allen was the co-founder of Microsoft, the American company that built and sold the operating systems and applications software that became the standard layer for personal computers, and the founder of Vulcan Inc., his private holding company for a diversified portfolio of businesses, investments, and philanthropy. After leaving Microsoft's day-to-day operations in the early 1980s, he directed personal capital across sports franchises, aerospace, brain science, and the arts rather than running one operating business.

Background

Paul Gardner Allen was born on January 21, 1953, in Seattle, Washington. His father, Kenneth Sam Allen, was associate director of libraries at the University of Washington, and his mother, Edna Faye Allen, was a fourth-grade teacher. He grew up in the Wedgwood neighborhood of northeast Seattle, surrounded by books, with a mother who brought home thrift-store volumes at fifteen cents each and ran his grade-school science club.

Allen attended Lakeside School in Seattle from 1965, one of the only U.S. high schools then with a computer lab. He scored a perfect 1600 on the SAT, attended Washington State University, and dropped out after two years to take a programming job at Honeywell, chosen deliberately for its closeness to Harvard, where Bill Gates was enrolled. Allen had met Gates at the Lakeside computer terminal in the fall of 1968, when Allen was fifteen and Gates twelve; the two studied discarded operating-system source-code printouts they retrieved from behind a local computer lab.¹

Getting started

In 1972, Allen and Gates, then eighteen and sixteen, co-founded Traf-O-Data, a venture that processed automated traffic-counter data using the Intel 8008 chip. Allen wrote a software emulator for the 8008 on a university IBM System/360 to test code before the physical chip was available. The demo failed before the county client, and the venture made roughly twenty thousand dollars before a government agency began offering an equivalent service for free.¹ Allen later called the experience formative rather than wasted.

In December 1974, during a snowstorm, Allen spotted the Altair 8800 on the cover of Popular Electronics at a Harvard Square newsstand and ran to Gates's dorm room. The two telephoned MITS, the machine's maker, and its head Ed Roberts, claiming they already had a working BASIC interpreter for the Altair, though they had not written a line of it, and Roberts offered a demonstration slot weeks away. Over about eight weeks Gates stopped attending class while Allen modified a DEC assembler and wrote another 8080 emulator to build and test the software without touching real Altair hardware. On the final descent into Albuquerque, Allen realized he had forgotten the bootloader and wrote it by hand in 8080 machine code on a steno pad.¹ The demonstration succeeded, and Roberts hired Allen as vice president and director of software.

What he built

On April 4, 1975, Allen and Gates co-founded Microsoft in Albuquerque, New Mexico. Allen coined the name "Micro-Soft," and the first employee was Ric Weiland, a Lakeside classmate. The initial equity split was 60-40 in Gates's favor rather than 50-50, and Gates later renegotiated it to 64-36; at Microsoft's 1986 IPO Allen held roughly 25.2 percent of the company.¹ Diagnosed with Hodgkin's lymphoma in 1982, Allen stepped back from daily operations, though he remained on the board until 2000.

In 1986 Allen founded Vulcan Inc. with his sister Jody Allen to manage his business, investment, and philanthropic portfolio. He bought the Portland Trail Blazers of the NBA in 1988 for seventy million dollars and the Seattle Seahawks of the NFL in 1997 for two hundred million dollars.² The Seahawks won Super Bowl XLVIII in February 2014. He announced the aerospace venture Stratolaunch in 2011, which built the largest airplane by wingspan; its first flight came in April 2019, after his death. He launched the Allen Institute for Brain Science in September 2003 with an initial one hundred million dollar gift, ultimately contributing more than five hundred million dollars. In 2011 he published the memoir Idea Man, a New York Times bestseller that aired grievances about being under-credited relative to Gates in Microsoft's founding.² Allen died on October 15, 2018, in Seattle at age sixty-five, of septic shock related to non-Hodgkin lymphoma diagnosed in 2009. His estimated net worth at death was about 20.3 billion dollars, with lifetime giving cited at more than two billion dollars.

How he operates

Allen described himself as "the visionary" to Gates's "executor," saying he was "always pushing in terms of new technology and new products" while Gates was "more interested in negotiations and contracts and business deals."³ A recurring technical method was to write emulators for hardware he had never touched, testing in the abstract before physical access. From the Traf-O-Data experience Allen believed that a false step in one direction can position a person to push ahead in another.³ After Microsoft, rather than running one company, he allocated personal capital through Vulcan across pro sports, aerospace, brain science, software, and real estate, a pattern he attributed to intellectual curiosity.

Where things stand

Allen has been deceased since 2018. Vulcan Inc. wound down its direct investment and holding operations after his death, while philanthropic vehicles including the Paul G. Allen Frontiers Group and the Allen Institute continued under separate governance. The Seahawks and Trail Blazers ownership passed into estate and trust structures, and the Trail Blazers were sold in 2025 to a group led by Tom Dundon. His legacy is discussed primarily as a visionary who saw technology shifts first, set against Gates as the executor.

Key facts

• Wrote working software emulators for the Intel 8008 in 1972 and the 8080 three years later, before ever touching the physical chips.
• Wrote the Altair BASIC bootloader by hand on a steno pad during the plane's descent into Albuquerque, hours before the demonstration.
• Coined the name "Micro-Soft" and accepted a 60-40 equity split with Gates that Gates later renegotiated to 64-36.
• Bought the Portland Trail Blazers in 1988 and the Seattle Seahawks in 1997 and founded the aerospace venture Stratolaunch, funding a portfolio from personal wealth.
• Held an estimated net worth of about 20.3 billion dollars at his death in 2018, with more than two billion dollars given away during his lifetime.