Form Factor????

[yahoo]

Please help I am confused :
How can I recognise which form factor is a mother board at first view ???? and the same question for the cases and the power supplies...
thanx for helping me ....

[Whyzman]

Hello yahoo,

Welcome tohttp://www.pcguide.com/ubb/pcgubb.gif Forums!

You might want to have a look right HERE (http://www.pcguide.com/ref/case/formATX-c.html) at our own PC GUIDE.

[integral]

The most common form factors are AT and ATX, there are others which can be found is some proprietary systems, HP, Compaq etc.

The AT form factor is now pretty much obsolete but is still found in older systems. Anything older then a 200Mhz PII is likely to be a AT formfactor. Genereally an AT mobo will have a large keyboard connector rather then the smaller PS2 which is currently standard. AT mobos have headers for the serial and parallel ports with ribbon cable connectors to the external connector which could be mounted in a slot plate or often to the rear of the case, there was no standard postition on the back of the computer for these connections. The AT power supply connected to the mobo with a pair of connectors each with single row of pins, the pair were mounted so close together they appear as one on the board, the key was the 2 black wires went together in the center.

This leads to the AT Power supply which had the AT power connector as well as a 120V switch of the front of the case, so an AT PS, when not installed is easily ID'd by the heavy cord and power switch which are attached in additon to the wires for the moboe and drives.

The ATX mobo has all of the various ports keyboard, mouse, Serial, Parallel and USB all mounted to the edge of the mobo, in addition the color of these ports are all speced so look for colorful connectors mounded to the mobo. The ATX power supply in connected to the mobo with a single 20 pin connector housed in a white plastic shell consisting of 2 rows of 10 pins each.

The ATX power supply has the ATX style mobo connector as well as no exteranl AC power switch.

There are a number of 'hybrid' mobos out there (FIC 503+) which has both AT and ATX power supply connections, generally they will not have the ATX style port connectors.

[Paleo Pete]

AT motherboard:

[Paleo Pete]

ATX Motherboard:

[YODA74]

http://users.erols.com/chare/atx.htm