IBM approached Microsoft for IBM PC

In July 1980, IBM’s internal “Project Chess” team, led by Jack Sams, contacted Microsoft to discuss software requirements for a confidential personal computer initiative that would later become the IBM Personal Computer. At the time, IBM was seeking programming languages and an operating system for a new microcomputer based on off-the-shelf components. Microsoft, then primarily known for its BASIC interpreters, was approached because IBM already used Microsoft BASIC in several products and viewed the company as a potential supplier for the new machine’s software stack. During the initial discussions, Microsoft indicated it could provide programming languages, including BASIC, but did not yet have a disk operating system available. Microsoft co-founder Bill Gates referred IBM to Digital Research, whose CP/M operating system was widely used on microcomputers. Subsequent negotiations between IBM and Digital Research did not result in an agreement. IBM returned to Microsoft later in 1980, which led Microsoft to secure the rights to 86-DOS from Seattle Computer Products. That software became the foundation for PC-DOS for IBM and MS-DOS for the broader market, released in 1981 alongside the IBM Personal Computer.