Some standard ATX power supplies do have such a switch (a hard switch...usually as a rocker switch on the back), but these also require the PSON signal (green wire, pin 14 on the ATX connector) to be grounded (black wire). Grounding the green wire should also work for a standard ATX power supply that does not have a hard switch, but then the power will be on whenever the AC power cord is plugged in.
Where can I get a power supply that will work with PC164 unmodified?
We can sell a custom-made 300-Watt power supply (see bottom of this page) that includes a "plunger" switch that goes to the front panel of the system (so you don't have to reach around to the back).
That sounds expensive, is there a lower cost solution?
We can provide AlphaPC 164 motherbaords with a special engineering fix that will allow them to be used with a standard ATX power supply. We recommend that it be used with a power supply that includes a hard switch, or else the power will always be on as long as the AC cord is plugged in.
How does this engineering fix allow PC164 to work with a standard ATX power supply?
It grounds the PSON signal on the motherboard, so that the power supply does not have to be modified. This effectively tells the power supply to always stay on. If the power supply has a hard switch, though, that switch will override this signal, so it can be used to power the system on and off.
What are the disadvantages to this engineering fix?
The power button on most systems is on the front panel, so that it is easy to reach. Most hard switched power supplies implement the switch as a rocker switch directly on the power supply unit, so the switch would be located at the back of the system instead of the front.
I have a standard ATX power supply without a hard switch, but I don't want my system on all the time. Is there anything I can do?
You could use a switched outlet or a surge protector to switch the AC power on and off to the system.
What capacity power supply does PC164 require?
We recommend at least a 250W power supply for lightly loaded systems. For systems with multiple hard drives or large amounts of DRAM, we recommend at least a 300W power supply. Extremely heavily loaded systems may require a 400W power supply or greater.
