Even as he grows older, Microsoft founder Bill Gates still fondly remembers the catalytic computer code he wrote 50 years ago that opened up a new frontier in technology.

Gates and his Microsoft co-founder, Paul Allen, used a computer in Harvard's lab to compose what he calls the 'coolest code I've written.' It's now public for the first time.

Reminiscing about Microsoft's early days, Gates said Altair BASIC was the company's "original source code," predating iconic products like Windows and Office. While he went on ...