On 18 Jan 99, at 21:55, Delano Lalla wrote:

> Can someone tell me the difference between an AT motherboard and an
> ATX motherboard.  Same goes for cases. Does it have anything to do
> with the Keyboard interface?


I have been researching this question for the last month (first I'd heard
of the ATX form factored motherboard), in planning for the construction of
my new PC.

I've found the following unique features of the ATX.

1-I/O connector panel is a built-in double height configuration.  The
external connectors are on the board rather than a bouch of cables running
from internal connectors to the back of the case.

2-single keyed power supply connector.  The MB power supply line does not
have the risk of interchanging two connectors and frying the MB.  The
connector has several pins that provice 3.3v to MB, so the MB does not need
the built=in voltage regulators.

3-improved air circulation/cooling.  The CPU and RAM are positioned to
facilitate air circulation.  The are cooled directly by the PS fan.  Some
vendors claim this eleminates the need for another cooling fan , but I am
not convenced.

4-Internal I/O connectors moved closer to their destination.   The H/F DD
connectors are moved so they are near the drive bays, reducing the lenght
of the internal cables are shorter, and rendering access to the connectors
much easier.

5-CPU & RAM no longer block any of the adapter cards.  This also makes it
easier to work on them, without having to remove other parts.

Other than these points, there is not much difference.

Jim
91B4S

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