Ibutton eeprom 256 bit dallas semiconductor ds1971 f5 this ibutton device is a rugged read write data carrier that can be used to store and identify information with a 256 bit eeprom memory the device can be used in a wide variety of applications where product or personnel data are required to be accessible br br as part of an ibutton system the data is easily written and accessed and the durable microcan package is highly resistant to harsh environments making this device suitable