Digital patents: US5491774: Handheld record and playback device with flash memory US5742737: Method for recording voice messages on flash memory in a hand held recorder US5787445: Operating system including improved file management for use in devices utilizing flash memory as main memory US5839108: Flash memory file system in a handheld record and playback device Some of the patents cover a lot of basic ground and have the potential to touch a large number of gadget makers, if the lawsuit is upheld.
