Thanks for the very good explanation of this function.  I have one of the 
newer ATX boards with Windows 98 installed so it should "Power off" 
automatically.  When I first installed Windows 98, the power off function 
did work when I did the Start -> Shutdown. After installing other software 
and doing other initial setup changes, the function has stopped working.  I 
think that during this time, I probably changed some of the APM settings 
somewhere (BIOS, Windows???) that caused the problem.  Where should I look 
and what should I change to get the Power Off function working again?

Doug

At 7/24/00 01:22 PM -0400, Oscar Viñas wrote:

>The newer motherboard form factors, such as ATX and NLX, include special new
>signals not present in previous Baby-AT or LPX form factors. One of them is
>called PS_ON or Power_On (pin 14), the other is 5VSB or 5v_Standby (pin 9).
>They both can be used to turn the power supply and the system on or off via
>software. PS_ON is specially evident when you use it with an Operating
>System that supports the Advanced Power Management - APM (Windows 95 and
>later) or Advanced Configuration and Power Interface - ACPI (Windows 98 and
>later) specifications. When you select the Shut Down option from the Start
>menu, Windows automatically turns the computer off after it completes the
>operating system shutdown sequence. A system without this feature only
>displays a message that it is safe to shut down the PC.
>
>The PS_ON signal is also used to power up the system. In these form factors,
>the front panel Power switch doesn't physically control the power supply's
>access to the 110v AC power. Instead, the power supply's on or off status is
>toggled by a PS_ON active low signal received on pin 14 of the ATX connector
>FROM the motherboard. The 5VSB signal on pin 9 is always active whenever the
>power supply is connected to an AC power source. The 5VSB signal provides
>the power for the remote switch  on the case to operate while the computer
>is off and gives the motherboard a limited source of power even when off and
>enabling new features to be implemented such as "Zero Voltage Modem Wake up"
>or "LAN Wake up", in which a signal from a modem or network adapter can
>actually cause a PC to wake up and power on. Another option is the Wake Up
>Timer, which wakes up and power up your system at a predefined time for
>specific application.

>----- Original Message -----
 > At 7/19/00 09:30 AM -0600, Bob Wright wrote:
 >
 >I believe you mean NLX form factor...
 ><snip> The ATX form factor moves the switching
 >to the motherboard, allowing for the Bios and Operating System
 >to control power, (ie: the motherboard can be powered down
 >to sleep mode or turned off).
====================================
> >From: Doug Simmons <[log in to unmask]

> > I think this relates to my question on PCSOFT about Windows 98 doing the
> > power off rather than display the "It is now Safe to Shutdown Your
> > Computer" message.
> >
> > How does Windows 98 "know" that the computer is of the ATX form factor?

                         PCBUILD's List Owner's:
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                       Drew Dunn<[log in to unmask]>