I need a linear power supply that regulates the negative rail(-12V) using NPN power transistors like 2N3771, 2N3772, MJE802 and so on, a PNP driver (TIP32 or equivalent) and LM723(or equivalent) as the voltage regulator.
One option is to configure LM723 regulator and external power transistors in "normal" positive voltage regulator and use the output (+) rail as "new" 0V and the "former" GND rail as "new" -12V output .. see picture below .. http://www.spaennare.se/psupply.html