This is a USB (universal serial bus) interface board which can be used to connect 8 (parallel) data lines to the USB. The interface comes with a small internal FIFO (384 byte Tx, 128 bytes Rx) and 4 handshake lines which make it suitable for interfacing microcontroller designs to the USB.
http://www.triplespark.net/elec/periph/USB8Bit/
Basically, USB-AtmelPrg is an USB-based "universal interface cable" connecting a host computer to the programmable device such as a microcontroller or a CPLD.
http://www.triplespark.net/elec/pdev/usb-atmelprg/
That mini usb connector port on your camera, external hard drive, music player may allow your devices to be small and hip-looking, but they seriously lack the structural rigity of their pretecessors (RS-232, Parallel) The following is a quick fix guide to solve this problem.
http://rpi.edu/~kouttd/03/fixing%20an%20external%20HD.html
The GP2X is an handheld running Linux. It has 2 arm-processors and a few peripherials, amongst others an usb host function. The usb host function is available through the ext-port, but no 5V is available there, so in order to get usb from that you'll either need a wall wart to supply the 5V or use a DC-DC-converter to generate 5V from the 3.3V that is available from the ext-port.
http://spritesmods.com/?art=gp2xusb
The FT8U232AM requires a small number of external components to produce a device that converts USB to TTL level RS232 signals. All you need to add is a TTL to RS232 converter to provide the 12V RS232 logic levels.
http://www.pccompci.com/usb-converter/usb-converter.html
This stuff looks great and you can even plug a hard-drive. The main issue is that the firmware only support 999 files on a single USB device, so that is enougth for 4Go of MP3 but not more.
http://www.larsen-b.com/Article/257.html
If you connect the TTL outputs of the RS-232 receivers to the (TTL) inputs of the RS-232 drivers, you effectively get the original signals with plenty of current for any serial-powered device with an extremely simple circuit using MAX205.
http://www.qsl.net.nyud.net/eb4eqa/serial_booster/serial_booster.htm
Here is how to interface a PIC18F452 to a PC via the USB port. The PIC captures the ambient temperature with a SPI sensor TC77. Its value is then transferred to the USB-interface.
http://www.techdesign.be/projects/017/017.htm
http://ourworld.compuserve.com/homepages/Bill_Bowden/page3.htm#spr
This is a basic RS-232 transmit/receive circuit that is necessary for PIC microcontrollers to reliably communicate with a PC serial port.
http://www.semifluid.com/RS-232_level_converter.html