Many IBM PC compatible games released between 1981 and about 1990 were self-booting and did not use MS-DOS, IBM PC DOS, or compatible disk operating systems. The phrase "IBM PC compatible self-booting disk" is sometimes shortened to "PC booter". Self-booting disks were common for other computers as well.
These games were distributed on 5+1⁄4" or, later, 3+1⁄2", floppy disks that booted directly, meaning once they were inserted in the drive and the computer was turned on, a minimal, custom operating system on the diskette took over. This was used as a form of copy protection[citation needed] until it became obsolete as games grew larger. Due to bit rot, original working versions of these floppy disks are rare. Some have been ported to other operating systems.
