IBM DemiDiskettes
In the early 80s, IBM Rochester developed a 4-inch floppy diskette, the DemiDiskette. This program was driven by aggressive cost goals, but missed the pulse of the industry. The prospective users, both inside and outside IBM, preferred standardization to what by release time were small cost reductions, and were unwilling to retool packaging, interface chips and applications for a proprietary design. The product never appeared in the light of day, and IBM wrote off several hundred million dollars of development and manufacturing facility. IBM obtained patent number U.S. Patent 4,482,929 on the media and the drive for the DemiDiskette. At trade shows, the drive and media were labeled "Brown" and "Tabor".
Read more about this topic: Floppy Disk Variants