Thanks John of I am Not a Geek dot com for the heads up on this one.
The ASUS P4B is an i845 based P4 board that uses SDRAM. This board has a lot of unique features you have probably not seen on other boards, such as digital audio out, and support for old non-P4 power supplies.
Quote: "ASUS has done something nice to save you some money if you are upgrading your PC. Usually when using a P4 board you need one of the newer power supplies that has ATX +12V power connector. If look at the picture of the board above, between the ATX connector and floppy drive connector, you will the same type of 4 pin power connector your hard drives use. If you do not have one of the newer power supplies you can use this connector instead to supply the extra 12V connection that the P4 requires. This patented technology is known as ASUS EX Plug."