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.
TRS-80
Radio Shack introduced floppy drives in July 1978, about six months after the Model I went on sale. The Model I disk operating system TRSDOS was written by Randy Cook under license from Radio Shack; Randy claims to have been paid $3000 for it. The first version released to the public was a buggy v2.0. This was quickly replaced by v2.1. required buying the Expansion Interface, which included a single-density floppy disk interface (with a formatted capacity of 85k) based on the Western Digital 1771 single-density floppy disk controller chip. The industry standard Shugart Associates SA-400 minifloppy disk drive was used. Four floppy drives could be daisy-chained to the Model I. The last drive in the chain was supposed to have a termination resistor installed but often it was not needed as it was integrated into later cables.