The first P1 power connector to the motherboard have that
was used with the original ATX contained a 20-pin P1 connector.
The 20-pin ATX style connector or the Molex 39-29-9202 is
the industry standard ATX power-supply–to–motherboard main connector. It is utilized
in the SFX form factor or any other ATX-based variations and was first used in
the ATX form factor power supply.
The ATX standard recommends the colors for the wires that
are listed in Table 3.3, however, they could vary from manufacturer to
manufacturer since they are not required for compliance to the specification. The
pins are arranged looking at the back of the connector (from the wire and not
terminal side) as shown in the table since it shows that its orientation if the
connector plugged in was back-probed.
