update to 4th axis

Hi, i have a 3 axis CNC controller (sable 2015 from ebay) configurated in EMC2 like this:
PARALEL PORT
Pin 1 = Unused
Pin 2 = X Step Inverted=y
Pin 3 = X Directio Inverted=y
Pin 4 = Y Step Inverted=y
Pin 5 = Y Direction
Pin 6 = Z Step Inverted=y
Pin 7 = Z Direction
Pin 8 = Amplified Enable Inverted=y
Pin 9 = Amplified Enable Inverted=y
Pin 14 = Amplified Enable Inverted=y
Pins 10,11,12,13,15,16,17 Unused
Include custom HAL configuration =box checked

I want to install a 4th axis so i am planning to buy ebay item number:180993441260
Questions:
1) how do i have to configure the paralel port in EMC2 then?
2) What "amplified enable" does?
Thanks a lot

thank you andypugh
i configure it like this and it worked:
Pin 1 = Unused
Pin 2 = X Step
Pin 3 = X Directio
Pin 4 = Y Step
Pin 5 = Y Direction
Pin 6 = Z Step
Pin 7 = Z Direction
Pin 8 = A Step
Pin 9 = A Direction
Pin 17 = Amplified Enable
Pins 10,11,12,13,14,15,16,Unused
and it work. If i check Inverted boxes, it doesnt.
I sitl dont understand very well how it works.
Why if check the box it doesnt work and if i dont it does. What does and amplifier do? The signal has higher voltage? or what?.
Thanks a lot

Thanks a lot. Clear now