Joel Spolsky has a very interesting account of what it was like working as a program manager for Microsoft in 1992. We don't want to ruin the story, because it's a really good one that you should check out for yourself, but the gist of it is that Bill Gates used to be extremely hands-on with his software developers.
It's something that only a real programmer can do, something that company heads who are more business-oriented (Ballmer, Jobs) can't, because they can't drill down and actually understand the nuances of the development cycle. As a former programmer, I have to say that Gates deserves a lot of respect (even if his management style was pretty dicky) for pretty much actually knowing everything that was going on in his company for much of his reign. [INC - Thanks Jae!]