The 5-ampere LM78H05K and 10-ampere LM78P05K from National are both hybrids. You can synthesize their function easily enough, and understand it as well, by considering that it's a PNP pass-transistor and a lower-powered regulator, with some passive control elements in the "box" (TO-3 package) with it.

If you use a standard 7805 with a 3-ohm 1/2-watt resistor at its input, and connect an MJ2955 PNP transistor's base to the input terminal and its emitter to both the filtered positive supply and the resistor terminal not connected to the base, and other wise connect the regulator in the usual way, with the collector of the MJ2955 at the 7805's output, you'll have the basic circuit, though there's another resistor and transistor used to limit the short-circuit current so as to provide the thermal and short-circuit protections normally provided by the standard 7805. This is explained in the documentation, IIRC.

Those high-power regulators were very costly back in the '70's and early '80's, hence it wasn't unusual to see the discrete pass-transistor circuit built from discretes.

RE