Chagrin:
I'm not sure why you'd think there would be a better method. The A3977 only accepts high and low and doesn't care if that's a sine wave or square wave. You can't control the form of signal that the A3977 sends to the stepper by changing the form of signal that you're sending the step pin.
I understand that, but the reason that I think that there may be a better method is that I require the Arduino to do some other tasks at the same time, and constant serial read and write. This will interrupt the frequency of the pulse, thus affect the frequency of the output. I don't care about the form of the signal, just the consistency of it. If you are wondering why I think this to be the case, it is because it says so here...
http://arduino.cc/en/Tutorial/SecretsOfArduinoPWM
"One major disadvantage is that any interrupts will affect the timing, which can cause considerable jitter"
I cannot have "considerable jitter."
MarkT
Thankyou, I will look into BlinkWithoutDelay.