You can modify this Short Circuit Protection Diagram of Motorolla MC7800 Series by adding a short circuit
sense resistor, Rsc and a PNP transistor in order to provide supply
protection against short circuits. Specify a four-ampere plastic power
transistor while you use current sensing PNP transistor which must be
able to handle the short circuit current of the three-terminal regulator.
Even particularly designed as a fixed voltage regulator, the MC7800 Series can also be used with external components to obtain adjustable voltage and currents. The “XX” stands for 2 digits of type number indicating voltage (source: MOTOROLA ANALOG IC DEVICE DATA).