November 1, 1983: Steve Jobs Goes Ballistic
When Bill Gates announced Windows 1.0 before the Mac came out, Steve Jobs was furious, so furious he demanded that the Apple employee in charge of Microsoft relations get Bill Gates to Apple's campus the next day.
Bill Gates made the trip to Cupertino for what would be, obviously, a contentious meeting. The afternoon following the announcement of Windows featured ten Apple employees meeting with Bill Gates. Steve Jobs didn't hesitate to tell Bill Gates loudly:
"You're ripping us off! I trusted you and now you're stealing from us!"
Bill Gates had a different interpretation of events, opining that both companies were ripping off Xerox, and it was more a question of who was first. Legally and practically, Apple was in trouble, the company needed Microsoft software, and Xerox was the fount of GUI interfaces. Still, the showdown makes for a good story and occurred this month in 1983.

Comments
Fortunately the practical example set by apple meant that M$FT was never able to screw over another buisness partner.