USB MSC, the physical file system and layout are exposed to the user. Device control Many modern digital cameras from Canon and Nikon can be controlled via PTP from a USB host enabled computing device (Smartphone, PC or Arduino for example). As is the norm for PTP, the communication takes place over a USB connection. When interacting with the camera in this manner, it is expected that the USB endpoints are in (synchronous) Bulk Transfer Mode, for getting/setting virtually all the camera's features/properties (such as ISO, Aperture, Shutter speed and focus). Events raised by the camera, in response to specific actions performed by the host device, are sent back to the host via the USB asynchronous Interrupt endpoint. In addition to changing the camera's settings and operating mode, it is possible to receive a through-the-lens view using "Live View". As described above, the storage objects of the camera's memory cards can be manipulated too. By controlling a camera in this way it is possible to augment its capabilities. For example, if the controlling software was running on a Smartphone with GPS functionality, it would be possible to add the GPS coordinates to an image's Exif data, at the time of image capture - even if the camera itself had no GPS functionality. Extensions A number of protocols have been developed that extend PTP. PTP/IP, developed by FotoNation and first implemented in a round of Wi-Fi digital cameras by Nikon, Canon, and Eastman Kodak, allows data transfer over any IP-based network. Media Transfer Protocol (MTP), developed by Microsoft, allows for transfer over wireless or wired networks based in part on FotoNation's PTP/IP, but also allows users to transfer other media aside from pictures, as well as for tagging objects with extended metadata (such as title, artist and similar). Operating system support Microsoft Windows has supported PTP from Windows ME onwards (excluding Windows CE). Microsoft implements PTP on Windows through Windows Image Acquisition. A disadvantage of PTP on Windows as compared to USB mass storage is that Windows does not assign drive letters to PTP devices, so image files on them cannot be manipulated by scripts or standard Windows programs, only by Windows Explorer or applications with specially written PTP support. Also, Windows Explorer does not display file modification timestamps (though these are available via the file Properties popup). PTP on Linux and other free and open-source operating systems is supported by