Intersections and No FMC's?

[G-BPEC]

Another silly question from a wannabe...

Obviously large airliners such as the Boeing's have complex and detailed Flight Management Computers, and so if cleared to an Intersection which isn't a VOR/NDB etc, et LISTO, WILLO etc. they simply select the wypoint, move it to the top and select LNAV.

My question is, how do older IFR passenger aircraft such as some props get to these points?

Also, can any Dash 8 operators tell me if their aircraft are equipped with FMC's? I am particularly interested in the Brymon fleet.

Thanks
G-BPEC