ATX

Sometimes referred to as the Full-ATX, the ATX motherboard is one of most commonly found and used motherboards even today. ATX is an Intel trademark and not an acronym that was first designed and released in 1995 by Intel and revised to version 2.01 in February 1997. The ATX motherboard is 12" wide x 9.6" deep and has the COM port, LPT port, PS/2, and USB mounted directly on the motherboard. Below is a picture and example of what this form factor of motherboard may look like.

 

Below are some distinct advantages and methods of identifying a computer with an ATX motherboard.

1. The ATX motherboard includes advanced control facilities, where the BIOS program continually checks the CPU temperature and voltages, the cooling fans RPM, etc. If over heating occurs, the PC will shut down automatically.
2. The ATX motherboard has a stacked I/O connector panel mounted on the motherboard.
3. On a socket 7 ATX motherboard, the socket has been placed a further distance from the expansion slots, allowing for long boards to be placed in easier.
4. Single keyed internal power supply connector. This is the Molex power connector, ATX 2.01. Standby voltage needs to be greater than 720 mA. The connector now cannot be placed in improperly. While the Molex power connector allows for 5v and 3.3v to be connected, it is recommended that only a 3.3v be connected to the motherboard.
5. Relocation of the memory and the CPU creating better ventilation and easier upgrade.
6. Power management possible with proper BIOS support.
7. The PC can also be turned on by a modem or network signal, since the power supply is controlled by the main board.
8. The computer cannot be turned off as the computer boots. However, if the computer freezes as it is turning on you can turn off the computer by holding the power button for 5 seconds.

Also see: ATX style connector, BTX, Form factor, Motherboard definitions