As he prepares to turn 70 later this year, Microsoft founder Bill Gates' new memoir explores how his childhood quirks, upbringing, friendships and experiences coalesced into shaping his internal operating system.

The first in a planned trilogy of books about his life, Source Code covers Gates' remarkable childhood in Seattle, his brief stint at Harvard, and the early years of “Micro-soft” in Albuquerque. This is not the behind-the-scenes story of today’s trillion-dollar tech giant.

In his new autobiography, the computer pioneer and philanthropist writes of his origins, and about how, in eighth grade, he discovered BASIC, which introduced him to the elegance and exacting demands of computer code.