Yes you can use an on-board keyboard, in fact Mach has a numeric one, you can use for DROs, built in.
Operator menu the Auto Calculator and then each time, after you have chosen the option, that you click a DRO it will pop up.
It is only numeric though so does not work from MDI.
You can add an on screen keyboard, even Windows has one built in but personally I found they just got in the way and I didn't like them.
Hood