Currently, two types of power supply can be distinguished, namely AT and ATX power supplies.
AT power supplies has a long established history. From the era of 386 and 486 processors to the current Pentium processors, AT power supplies have been the mainstream product. However, as present and Management Interface), the ATX standard will be the mainstream standard of the future.
So what is the difference between AT and ATX power supplies? The easiest way to establish the difference is to take a look at the power supply connector on the motherboard. An AT-style motherboard connector has two parts (a P8 and P9 connector) with each six pins. An ATX-style motherboard connector consists of one single 20-pin connector with fool-proof design, so you do not have to worry about burning your motherboard in case you connect the connect the power supply incorrectly.