Please can anyone assist me with the write up of speed control of stepper motor using AT89c51

STEPPER MOTOR CONTROL USING
89C51 MICRO-CONTROLLER
This controller can control the rotation of a DC stepper
motor in clockwise and anti-clockwise
directions.It has application in machine control and
robotics. the block diagram of the
stepper motor control system has a power supply, microcontroller board, contrl section. Atmel
AT89C51 is a powerful, highly flexible and
cost-effective solution to many embedded
control applications.

Circuit description
When power
supply switch S1 is closed, LED1 glows
to indicate the presence of power in the
circuit. The capacitor provides the power-on reset to the
microcontroller. When transistors conduct, current flows through the coils and they create magnetic fields
and the motor starts rotating. the magnetic
field collapses and a reverse voltage develops and the motor stops.

Clock and reset circuit.:
The speed of the stepper motor
is proportional to the frequency of the input
pulses. The Reset switch (S2) allows you to reset the
program without having to interrupt the
power.

Driver circuit design:
The microcontroller
outputs a current of 1.7 mA. An amplifier must be used to boost the current. a driver circuit using
transistors SL100 and 2N3055 amplifies the current to 2.7 A.

Programming:
The program is written in Assembly language
and compiled using ASM51 crossassembler.One-step equals 1.8 degree. 200 steps make 360 degree. the
step sequence for 100 steps to energise the
windings of the stepper motor in clockwise
and anti-clockwise directions. is orecisely written in the program. For the pdf and the program listings, see:
http://kitsnsparesadmin/pdffiles/Stepper%20Motor%20Control%20using%20Microcontroller.pdf