Using 3N128 mosfets as 12V controller with microcontroller
No, no - the 3N128 is an ancient depletion mode MOSFET requiring a negative voltage to switch it "off" i.e. it is normally "on" with no gate voltage. It won't work as a substitute in the motor controller unless you can provide a negative voltage on the gate with respect to source (0V): -



It's only good for an on current of perhaps a few mA too which rules it out of all but nano-motor applications!