The second Apple-IBM dealBy the early 1990s, however, it was clear to Apple that Microsoft presented a bigger threat than IBM did. In April 1991, he gave a demo to IBM engineers showing an Apple operating system running on an IBM PS/2 Model 7 PC. That led to the Apple-IBM deal on this day in 1991, in which the two rivals agreed to work together. IBM would help Apple finish its “Pink” operating system (the one Apple engineers created to run on IBM’s computers). Still, the Apple-IBM deal certainly shocked the hell out of Apple fans in 1991.