BIOS Microsoft IBM operating system PCs personal computer integrated circuit
Because the IBM PC was based on relatively standard integrated circuits, and the basic card-slot design was not patented, the key portion of that hardware was actually the BIOS software embedded in read-only memory. This critical element got reverse engineered, and that opened the floodgates to the market for IBM PC imitators, which were dubbed "PC clones". At the time that IBM had decided to enter the personal computer market in response to Apple's early success, IBM was the giant of the computer industry and was expected to crush Apple's market share. But because of these shortcuts that IBM took to enter the market quickly, they ended up releasing a product that was easily copied by other manufacturers using off the shelf, non-proprietary parts. So in the long run, IBM's biggest role in the evolution of the personal computer was to establish the de facto standard for hardware architecture amongst a wide range of manufacturers. IBM's pricing was undercut to the point where IBM was no longer the significant force in development, leaving only the PC standard they had established. Emerging as the dominant force from this battle amongst hardware manufacturers who were vying for market share was the software company Microsoft that provided the operating system and utilities to all PCs across the board, whether authentic IBM machines or the PC clones.
