Reserve pin fool proves the connection by allowing the connection only in a single way.
If it as a 20 or 24 pin connector and a 4 pin connector then it is a ATX power supply.
The atx 12 connector is one of the motherboard power connectors and used for 12 volt power connect for cpu voltage regulator.
8-pin power supply connector with 150 watts
the optical drive will connect to the power supply with a connector called molex connecter it is a 4 prong connector
24 pin connector is required to supply power to the motherboard.
Power Supply Connector
8-pin power supply connector, 150watts
No FireWire does not need a separate power supply to operate. FireWire is used to connect peripheral devices to a computer.
The most common power supply connectors for motherboards will be either a 20 or 24 pin connector. Older unit used less pins like the ATX but the cure standard is the 20 or 24 pin main connector.
A "Berg" connector.
It connects the drive to the system power supply.
I know it as a P4 power connector. it works for many CPU's.