Here, I see the version Jaguar linked to has added the moderate scales, just like the FIRO grid (but with half the points in each dimension): Understanding DISC

The factor poles of Assertive, Open, Controlled, Receptive now become the new "moderate" types. There is also a moderate-in-both-dimensions type, "Balanced", in dead center.

The original four types are renamed in this grid for some reason:

Driver (Dominance)
Communicator (Influence).
Planner (Steadiness)
Analyst (Compliance)