What is the theory/mechanism of segatool?

[bnomad]

I am literally a newbie to either this website or the world of arcade.

Driven by the mind of writing/adjusting the segatool in order to make it compatible with kancolle arcade, I wonder what is the theory of segatool?

Btw, dealing with basic i/o and digital input/output always reminds me to somewhat assembly language. If it is required to well grasp the skill of assembly programming?

Any advice is welcomed, big thanks guys