The 90s deal, per Forbes:
http://www.forbes.com/sites/ericjackson/2012/03/01/steve-job..."I called up Bill and said, “I’m going to turn this thing around.” Bill always had a soft spot for Apple. We got him into the application software business. The first Microsoft apps were Excel and Word for the Mac. So I called him and said, “I need help.” Microsoft was walking over Apple’s patents. I said, “If we kept up our lawsuits, a few years from now we could win a billion-dollar patent suit. You know it, and I know it. But Apple’s not going to survive that long if we’re at war. I know that. So let’s figure out how to settle this right away. All I need is a commitment that Microsoft will keep developing for the Mac and an investment by Microsoft in Apple so it has a stake in our success." -- Steve Jobs.
Reading between the lines, a less polite version is that Jobs went to Bill Gates and said, "I need a lifeline. Apple is circling the drain. You are going to throw me that lifeline. We are going to do a deal whereby I drop our patent suits against you, and in return you invest in Apple and support us with Office, and say we're best buddies in public. Or else I wind up Apple as a computer company and spend the remaining billion dollars in our accounts on turning Apple into the biggest, baddest patent troll ever. And I will go kamikaze on your ass, and there will be blood and screaming and absolutely no mercy, because I offered you this deal and you turned it down and I remember my enemies forever. Oh and by the way, the DOJ anti-trust folks will be watching. Deal or no deal?"
(This is quite distinct from the 1983/84 Jobs/Gates deal whereby Steve gave Bill an exclusive to be the first office app vendor on the Mac -- as described in "Fire in the Valley" and elsewhere -- which is how Word for Mac got started.)