I don´t think the breakout board has a name :-) But motor drivers are 3x M542. I´ve bought it all Ready to go in a case, with PSU, softstart, BOB, drivers from a guy who sells a lot of them, or did 4 years ago.
Yes, AT and PS2 are doing the same.
When I actualy try to Zero with the machine running and push the zero button, Z axis i moving few steps down and Zero the Z DRO - noise in Dell PC?
But I can do it only once, bacause the Digitize led stays On.