12.27 For More Information

To program a particular peripheral device, you will need to obtain the data sheets for that device directly from its manufacturer. Most manufacturers maintain their data sheets on the Web these days, so getting the information is usually a simple matter of finding their Web page. Some manufacturers do consider the interface to their devices to be proprietary and refuse to share this information (this is particularly true of video card manufacturers), but by and large it's relatively easy to get the information you need.

Semiconductor manufacturers are especially generous with the information they supply on their websites. Furthermore, common peripheral devices like the 8250 serial communications chip have dozens of websites dedicated to programming them. A quick search on the Net will turn up considerable information for the more common interface devices.

For USB, FireWire, and TCP/IP (network) protocol stacks, there is considerable information available on the Net. For example, http://www.usb.org contains all the technical specifications for the USB protocol aswell as programming information for various common USB host controller chip sets. Similar information exists for FireWire.

You'll be able to find considerable example code that controls most peripheral devices on the Net as well. This even includes some complex protocols such as USB, FireWire, and TCP/IP. For example, the open source Linux OS provides complete TCP/IP and USB host controller stacks in source form. This code is not easy reading and is tens of thousands of lines long, but if you're dead-set on creating this kind of code, the Linux (and other open source) offerings make a good starting point.