Yoshiro Nakamatsu
Nakamatsu claims IBM reached licensing agreements with him in the late 1970s. He also claims to have licensed his floppy disk to IBM in 1979, but that the details are "confidential". An IBM spokesman, Mac Jeffery, confirmed that the company did license some of his patents, but claimed they were not for the floppy disk, which he claimed IBM invented on its own. Another IBM spokesman, Brian Doyle, said they licensed 14 patents from Nakamatsu, but also claimed that they do not have anything to do with the floppy disk.
Macintosh External Disk Drive
Following the success of the Macintosh implementation of the -inch format, the format was also adopted widely by the personal computer industry. However most of the industry adopted a different Modified Frequency Modulation (MFM) formatting scheme at a fixed rotational speed, incompatible with Apple's own GCR with variable speed, resulting in a less-expensive drive, but with a lower capacity (720 KB rather than 800 KB). In 1987 a newer and better, MFM-based, "high-density" format was developed which IBM first introduced in their PS/2 systems, doubling the previous storage capacity to 1.4 MB. In Apple's pursuit of cross-compatibility with DOS and Windows-based systems to attract more business customers, they adopted the new format, thus confirming it as the first industry-wide floppy disk standard. However, Apple could not take advantage of the less expensive fixed-speed systems of the IBM-based computers, due to its backward incompatibility with their own variable-speed formats.