The model number of IBM’s first personal computer, released in 1981, was IBM 5150.
IBM introduced the IBM Personal Computer on August 12, 1981, after developing it in roughly a year to compete in a rapidly expanding microcomputer market. The machine was officially designated the IBM 5150 and soon became widely known simply as the IBM PC.
Unlike IBM’s traditional mainframe approach, the PC project used many off-the-shelf components and an open architecture. That strategy helped the team meet an aggressive schedule and encouraged outside companies to develop expansion cards and software. Microsoft supplied the operating-system options, including PC DOS, while Intel’s 8088 processor powered the system.
The model numbers in this question refer to later or different IBM machines. The IBM 5160 was the PC XT, introduced in 1983; the IBM 5170 was the PC AT, introduced in 1984; and the IBM 5110 was an earlier business-oriented personal computer from the 1970s. The 5150 therefore identifies the original IBM PC, not merely the broader product family.