Hi,
    I came across this video:
https://www.youtube.com/watch?v=iRAKprcp_Gw
Looks like a chinese breakout board:

open attachment

output Step/Dir and common (3 wire) to the input of MRJ2S CN1A, how is this done?
A while ago I had to use a couple of SSD in between the BOB and MRJ2S but this video make it look so simple, I know also by adding a 4.7K resistor between port 2 of the BOB then to MRJ2S CN1A would work too, can anyone explain the wiring in the video?

Thanks,