first you need to find the

[D.V.G. Krishna]

first you need to find the type of stepper you are using.

incase of unipolar stepper then

the control algorithm willbe

if(condition for forword)

while(condition for forword)

{ 

control port=0x11;   0001

       delay(); define as per the motor

control port=0x22;   0010

       delay();

control port=0x44;   0100

       delay();

control port=0x88;   1000

       delay();

if(condition for backword)

while(condition for backword)

{

control port=0x88;   1000

       delay();

control port=0x44;   0100

       delay();

control port=0x22;   0010

       delay();

control port=0x11;   0001

       delay();

}