Ok, I'll try that, cheers. So say I was to assign it to the ground on the top left of the board in the picture on the previous link. When I defined the steppers at the start what would I write?
i.e.
AccelStepper stepper1(1, 9, 8);
AccelStepper stepper2(1, 7, 6);
AccelStepper stepper3(?, 5, 4);