Microsoft Co-Founder Paul Allen has had some choice words for Bill Gates in recent weeks while promoting Idea Man, his upcoming memoir. But little is as damning as something he never got a chance to say to his former colleague: Some days working with you is like being in hell.

The quote comes from a 60 Minutes interview with Allen that aired last night. During the taping, Allen talks about the early days of Microsoft, his battles with cancer, and what it was like to be made miserable by the richest man in the world.

The segment also features footage of a younger Gates berating and yelling at colleagues, behavior that Allen says was a fairly normal part of Gates' management style. Gates often made personal attacks, Allen said, noting that it was often essential that employees yell back at the Microsoft CEO in order to express their convictions.

Allen has been forced to contend with charges that he is just a bitter billionaire upset for not getting his share of the recognition for Microsoft's rise. Allen denies that. It's not about that, he says, noting that his story is an important part of the history of technology.