I am using ìPSD3200 of ST and ìVision 2 of keil.
I already developed the controller but I want to upgrade it so it will be able to control more than one motor.
I do not know if you will succed, there will be a ton of timing issues (keep motor 2 running while processing motor 1 stall or whatever)
Do I need to use Real Time OS ?
NO, nobody need to use a RTOS and if you have timing problems a RTOS will only make them worse
Can I use the fork function and how?
What is a "fork function", I probably know it by another name.

Erik