5V supply in 3.3V systems

["Theo Lindebaum" <t.lindebaum@wavecom.ch>]

Hello everyone,

What does the spec say about the 5V supply in 3.3V systems?  Will the 5V
supply always be there, even on a 3.3V only PCI motherboard?  This relavent
when designing the supply for a "universal" 33MHz PCI card.

At the moment, our PCI card derives 3.3V from the +5V pins, as many older
motherboards just do not have the 3.3V supply on the pins.  Will this
approach still work in 3.3V PCI motherboards?

Regards,

Theo Lindebaum