ISA Voltage Regulator Cards?

stripey357 asks: "I'm trying to install a Dialogic Gammafax card in Pentium-based SCO unix box, and I've run into a problem. The power supply for this box doesn't supply -5v to the ISA, and that's the voltage the Gammafax wants. Do they still make ISA voltage regulator cards that can reg -12v down to -5v, or would it be easier to replace the power supply?"