The software code is build with the AVR BASCOM compiler

To run the stepper motor you need a terminal program such as Hyperterminal. To synchronize the terminal program with the stepper board you need to make the next settings in the terminal program: 
COM1 - 9600 baud - data bits 8 - 1 stop bit - No parity bit - No handshake.
The COM port can be set to the COM port that you use on your PC.

There are 4 commands that you can send to the stepper controller: 
m0rx and m0lx and m1lx and m1rx
The x in the command is a number from 0 to 32000. If you send the command m0l2000 the motor 0 turns clock wise 2000 steps and if you send m0r2000 the motor 0 turns counter clock wise 2000 steps.

After power up the board, a message is shown in your terminal program. You can then give the commands to control the stepper motors. See the example below.

pc steppermotor driver pic2