IBM PC Model 5150 with printer, 1981. Sure, the world had personal computers before the 5150 was introduced in 1981. IBM’s sales pitch—bringing Big Blue’s corporate computing prowess into the home—helped make this a wildly successful product. Even more influential than the 5150 itself was Big Blue’s decision to license its PC operating system, DOS, to other manufacturers. That led to the birth of “IBM Compatibles,” the forerunner to almost all non-Apple PCs out there today.