How They Really Work

Osher Lifelong Learning Institute
University of Illinois, Urbana-Champaign

Scott Badman, Instructor

Peripherals

Peripherals PowerPoint Presentation

Components in the connection

Pink is software or firmware

Blue is hardware

Yellow is the cable

The Application Program passes an input / output request to the Operating System by a procedure call to the Operating System.

The Operating System passes the information to the proper Device Driver by a procedure call to the Device Driver software.

The Device Driver sends binary information through the system busses to special hardware registers on the Interface Card.

Interface Cards usually are specialized, dedicated computers themselves. They create a stream of bytes according to the appropriate protocols, and send them over the cable using the proper electrical signals.

The Controller Card on the peripheral is also a dedicated specialized computer. It receives the stream of bytes, and then formats the information and sends the necessary electrical signals to operate the peripheral.

Typical input / output connectors, cables, and interface cards to connect to various peripherals - Power Point Presentation continued..

If the cable fits the connectors, and the drivers are properly installed, usually the peripheral will work properly.

Troubleshooting:

1. Make sure the application is properly trying to access the peripheral. Is it giving error messages? Do they give an indication of what the problem is?

2. Carefully test the device to see what is working properly and what is not working properly. Make sure you know how the peripheral is supposed to work. It may be installed properly, but you are not operating the peripheral properly.

3. Check and make sure the physical connectors and cables are properly installed.

4. Reboot the computer and turn the peripheral off and back on. Is the problem solved?

5. If none of the above solves the problem re-install the device driver and reboot the computer.

6. If that does not solve the problem, can you substitute another identical cable and peripheral to see if they work. If so, the computer is working properly and the problem is with the original peripheral.

7. Can you install the peripheral on another computer? If you can and it works, then the problem is with your original computer.

8. If none of steps above solves the problem, then try to get additional help, from manuals, the Internet, or a knowledgeable person.

9. If you still cannot solve the problem, can you get your work done some way that doesn't use the peripheral?

10. Replace the peripheral with a new, better one.