…so that extension cards and entire clones could be made. IBM had no intention of allowing clones. They relied on their proprietary BIOS to give them control o

…so that extension cards and entire clones could be made. IBM had no intention of allowing clones. They relied on their proprietary BIOS to give them control of the product even though they were licensing an OS from another party. This failed when the clean room reimplementations of IBM’s BIOS withstood IBM’s legal challenges and clones were born. IBM attempted to regain control of the platform by creating their own OS, OS/2, but ultimately failed and was driven from the market.