Your lpt control code example is for DOS, where each port or device had a static memory address. Under Windows all external device control is virtualized via drivers, and while you can send predetermined bit patterns, your program has little control over the timing of when they get there (ie, message-pump operating systems are not strictly real-time).
Stepper motors are generally programmed by sending high-level commands from the computer (via a serial port or ethernet) to a driver board which interprets the commands onto dedicated power electronics for the device. This sort of progamming is readily accessible from Fortran.
