Bill Gates unveils the Altair BASIC source code, 'the coolest' he's ever written

In a nostalgic nod to Microsoft’s origins, co-founder Bill Gates has released the source code for Altair BASIC, the software that marked the beginning of the tech giant’s journey.

This release coincides with Microsoft’s 50th anniversary, which will take place this Friday. Gates describes this milestone as both “bittersweet” and a celebration of innovation.

Altair BASIC, written by Gates and Paul Allen in 1975, was the fledgling company’s first product. It was designed for the Altair 8800 microcomputer, a groundbreaking device that inspired Gates and Allen to create software to make computing accessible to more people.

The source code, which you read here, written in Intel 8080 assembly language, is over 150 pages long and represents a pivotal moment in the history of personal computing.

Gates reflected on Microsoft’s early days, recalling the long hours spent coding on a PDP-10 computer at Harvard. He described Altair BASIC as “the coolest code I’ve ever written” and expressed pride in its role in shaping the PC industry.

This Friday, the Redmond-based tech giant will turn 50, and according to reports, Microsoft might also hint at the company’s future by unveiling some big surprises.