Re: I find this one a bit difficult to believe
Nope, it's used for a limited number of old ISA cards. If the ISA card is used in later motherboards that don't supply -5V, some/all of their functionality may not work. Serial ports still exist on modern kit, and there's no -5V on an ATX 2.x PSU.
It's still possible to buy PSUs with -5V on them if necessary.
Biting the hand that feeds IT
