the difference between grbl1.1h_dr_.hex and grbl1.1h_st_.hex (st and dr) is that if have installed first firmware and axe y move down (incontrary) when click y+ ... need to
installsecond firmware and will see that axe x working corectly!
250k and 9.6k mean that working with 250000 bauds and 9600 bauds respectively.
original https://github.com/gnea/grbl/releases/tag/v1.1h.20190825