Microsoft wins FAT patent

By Steve Malone

Posted on 11 Jan 2006 at 10:41

Microsoft has won its battle with the US Patents and Trademarks Office (USPTO) over its attempt to patent the File Allocation Table or FAT, which formed the basis of the management of disk storage in the days of MS-DOS.

The company applied for a patent on FAT in 1996. However, because the format had become so widely used, there were fears that Microsoft would use the FAT licence to drive out competition. A particular risk were open source projects which used FAT as a standard method of storage who feared that large royalty demands would curtail their work.

The USPTO has now reversed its earlier decision that rejected the patents in September 2004 and has upheld the patent having rejected claims by Public Patent Foundation of 'prior art' which would have rendered the application as invalid. The USPTO has also rejected two patent applications from Microsoft related to long file names in October 2005.

On its website Microsoft offers to licence the FAT IP. Pricing for this license is $0.25 per unit with a cap on total royalties of $250,000 per manufacturer. Among those who might find themselves on the receiving end of a royalty demand from Microsoft are likely to be Linux vendors and memory stick manufacturers.