Roman Heavy Cavalry Fighting Techniques

[Spurius Papirius Cursor]

I haven't done you guys the courtesy of reading this thread in detail as yet - apologies. I will - but I know if I don't respond now, I'll forget (old man blues).

I'm trying to get a sense of how Roman super-heavy cavalry were desired to function on a third - fifth century battlefield. Does anyone know of a period source that prescribes how they should be used?

My current impression is that the horse was meant to get the rider from the start-point to the enemy swiftly to somewhat thwart the defensive missile barrage. Once in front of the enemy (infantry e.g.) they fight (mounted) as taller, stronger, heavier and harder-to-wound infantry. I also gather the idea of a cavalry unit as a panzerfaust smashing through obstacles of all kinds is a 20th-century concept where tanks, armoured personnel carriers and helicopters do dramatically penetrate defensive lines.

Cheers