If anyone is curious about what an IBM 4" floppy drive looks like, I just uploaded a picture and the patent for it to http://bitsavers.org/pdf/ibm/floppy http://www.weblog.com/comments.aspx?blogid=30290&postid=71765 4-inch floppy diskettes In the mid-80s, IBM 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. CHM appears to have one http://www.computerhistory.org/collections/accession/X1140.93 Mismarked at 5 1/4" (grrrr..) And a disk http://www.computerhistory.org/collections/accession/102667528