if you havent gotten it figured out yet, what you just described. It sounds like the sequence is off or the motor is wierd worng as in how each coil of the wire is energised. Remember the common wire is the +v wire not ground. The only way to make the common the common ground is to use a PNP transister to drive the curent in the backwords direction. You can identify the common coil with an 0hm meter, testing for the resistance. High impendance means they are the coil wires, any one wire that keeps the ohms at half resistance is the common. A good program to play with is FKEYBIT. you can set the parallel ports data I/O pins high or low and figur out what the sequence of the motors are. then re-write the step program in turbocnc i.e. xxxx1000xxxx, xxxx0100xxxx, xxxx0010xxxx, xxxx0001xxxx. This is only for phase driving though. If you have a step to phase converter then its your wireing job more likly!
Remember half stepping would be 1000, 1100, 0100, 0110, 0010, 0011, 0001, 1001.
each 1 stands for an energised winging in the stepping motor. you just have to figur out the order of it. Its easyer to change the 4 wires, then it is to rewrite the stepping program. There are also other parts to the setup like how many steps to an inch. Which you must convert to a desimal which turbocnc then converts to the proper movements. so say you had a screw which took 20 turns to make a nut move 1 inch. and you have a 100step motor. well doing whole stepping, that would be 0.0005 th. of an inch. or 100 steps per motor rotation X (times) 20 turns of the screw is 2000 steps per inch. now to turn that into a desamal you take 1 inch devided by 2000 steps per inch. which gives you 0.0005. If you where half stepping you'd get 0.00025 thousands of an inch per step. If you want to cheat on that last one its 0.0005 devided by 2 provided your using the same motor/setup every thing! or half of a half is a quorter
!
any question's hesatate to ask, its all right there.