Use of conventional USB flash drives

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The Digital Talking Book player can use commercial off the shelf USB flash drives as a medium for holding DTB files.

The NLS player will suspend (put into a low power sleeping state) the USB drive when it is not being accessed. Some USB drives do not recover from such suspension and therefore cannot be used with the NLS player. It is possible that a quirk in the Linux USB driver interacts badly with some drives causing this problem however some drives are known to violate the USB specificat

The USB specification requires that all devices be capable of being placed in a low power suspend mode (drawing less than 500 uA).
For the DTBM, the great advantage of using this capability is that power consumption can be minimised (and battery life is greatly prolonged).

In commercial equipment is rare for this function to be used and it seems that Windows, OSX or Linux do not use this function in any normal use of USB flash drives.


Commercial USB Drives
Compatable Vendor ID / Product ID
Incompatable Vendor ID / Product ID
NLS Cartridge (all capacities)
058F/221B
Transcend Jetflash16GB
Lexar Firefly (all capacities)

Sandisk Cruiser
0781/XXXX
Mushkin Mullholland (all capacities)


PNY Attache (tested up to 1 GB)


Gigaware (Radio Shack) 4 GB
0781/555F



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