Difference between revisions of "USB Mass Storage on Android Devices"

Revision as of 23:58, 7 November 2014

Another working title for this page could be, "I just want to connect my phone to my PC and have it show up as a drive letter so I can easily transfer files."

USB mass storage is the standard protocol used by flash drives, external hard drives, SD cards, and other USB storage devices. It also was used by Android devices and even many basic phones. At some point the brains that develop Android decided to do away with this useful feature. They have legitimate arguments against the feature. Yet, the feature is very much missed by those who used it.

The new options, Media device (MTP) or Camera (PTP) mode, are either unavailable to Windows XP and other OS users, or too limited.

Why Android Devs Ditched USB Mass Storage

USB Mass Storage made it easy to connect your phone to a PC and transfer files. It was not necessary to install any special drives on the PC. The PC would detect the phone, and you could simply cancel the driver search dialog, and then wait a few seconds for the new drive letter to appear in Explorer/My Computer. Files could be transferred both ways. However, while connected and in USB Mass Storage Mode, which had to be set on the Android, the SD Card was unmounted and unavailable to the Android itself.

When connected to the computer, the mount point was disconnected from the Android operating system running on the device. Any files or apps stored on the SD card or USB storage would be unavailable when it was connected to the computer. This caused some interesting side effects. Icons for apps that were set to run from external storage would disappear from the Android desktop. Each app icon would have to be manually placed back on the desktop by the user. That is one example of a side effect.

Developers also didn't care for the limitations imposed on the format of the external storage. The SD card had to be formatted in a file system compatible with Microsoft Windows and therefore fees had to be paid to Microsoft for the right to use the format.

Why the alternatives fall short

MTP functions a lot like USB mass storage. For example, an MTP device shows up in Windows Explorer so you can browse and transfer files. Linux also include offers for MTP devices via libmtp. So, Android devs want us to use MTP as an alternative to USB Mass Storage. They say MTP is better because access to the external storage can be shared.

• Windows XP doesn't include native drivers for MTP.
• Apple Macintosh offers absolutely no support for MTP.

A Media Transfer Protocol (MTP) driver for XP is (was) available from Microsoft. However, Microsoft discontinued support for Windows XP in 2009. The MTP driver they offer is only partially functional and does not work with all Android devices.

Choosing the Camera (PTP) option is no substitute. This only allows you access to the DCIM (Camera image) folder on the Android, and files can only be "read." You cannot copy files from the PC to the Android in PTP mode.

Owners of the Samsung Galaxy Tab 2 (7.0) and a Windows XP computer have no resolution to these limitations. This particular tablet will not support USB Mass Storage mode, Samsung offers no driver, and MTP doesn't work with this device even when the Media Transfer Protocol (MTP) driver for XP is installed on the PC.