Also, can anyone teach me how to drive a stepper motor as I bought it already
Driving the stepper motor is the easy part, here is what you should do:
first you need to verify that the motor is working manually and identify the windings.
6 wires that means 3 coils right? I dentify each coil wires and put them in groups of 2, i.e 3 groups.
applying 12v directly to the wires should be no problem, if its good for 10.5v its good for 12v.
Apply 12 volts to one coil and see if the motor steps, mark these windings phase A.
apply 12v to another wire group and see direction of step, you can reverse the wires voltage applied to if step was in wrong direction. Mark this coil as phase B.
Mark the remaining wire group as phase C and apply 12 volts to it to make it step in the right direction, if you keep applying voltage in the following sequence A -> B -> C -> A .... the stepper motor should rotate smoothly.
Since you new the GND and + of each coil connect the grounds together of all the phases.
Now get suitable transistors like TIP31 etc, (connect a fast diode between collector and emitter of transistor for protection and a free wheel diode across each coil)and connect its emitter to each coil while collector goes to +12v. base is to the 8051 port pins or 8255 pins.
You should also put a big capacitor across Vcc for protection.
Read about stepper motors you can move them in full step mode or in half step mode.
Sequence should be Phase A, Phase B -> Phase B, Phase C -> Phase C, Phase A and so on .Duration of phase activation is by experiment to give you fastest speed so that the motor catches up with you, if you go too fast the motor won't move.
This is a practical introduction to keep you going, I done it myself and explained it to students working on a project and they loved it.
Regards
Mahmood