I have just got my machine going with a lot of help this forum,but when jogging the X axis is the wrong way. In other words from the Home Position, bottom-left I need to push the Left Hand arrow key to move to the right and the DRO display increasing Negative numbers. The wiring in the controller is identical for  X Y Z axis so I was hesitant to change it there. Is there any where in Mach3 to correct this problem?

Config -> Ports&Pins -> Motor Outputs -> Dir Low active

should help

Thankyou, that did the trick