This tutorial is interned for Unix users. If I am correct, small tweaking should allow it to work on Windows. Maybe some day I'll re-write it for Windows users.
Step 1: How it works
1. A perl script clocks the processor.
2. The script uses that number to come up with a number from 1-9.
3. The script throws that number to the Arduino, using Serial connection.
4. The script get repeated over and over, for an infinite amount of time.
5. Each time the Arduino receives ten numbers, it averages them, and shows the average on the bar graph.
It's as easy as that!