Power On: PS/2 Keyboard [motherboards that support this feature with USB interface]

[rox1co]

i like the Power On feature with the Keyboard, but i notice it's with PS/2 interface keyboards, are there mobos that support it with USB interface keyboards? i tried it with my mouse but its USB and it wouldn't work at all

i plan on getting a DFI board this summer but i'm just wondering about this feature since i really like it, thanks

 

[krotchy]

The problem is not in the keyboard design, It is in the interface. PS/2 is a socket designed directly for a keyboard and it interfaces directly with the motherboard. USB on the otherhand actually requires complex drivers and has to be enabled through a USB controller. The problem is, with the power off, there is simply nothing to talk to the USB keyboard, because your bios/OS does the talking to the USB ports.

However the advantage of USB over PS/2 I have found is that I have seen USB keyboards that can handle holding 5+ keys down at once. Some older or poorly made PS/2 keyboards cant even handle 2 keys simultaneously.

 

[rox1co]

ah that makes sense, well i guess i'm keeping this keyboard for a very long time and i don't ever hold down more than 5 keys, lol

 

[Peter]

Technically, some chipsets would allow powering the USB part from standby power ... but - with ATX 2.03 PSUs providing no more than 2 Ampéres of standby power, and up to ten directly connected USB devices that each may draw up to .5A, it just doesn't compute.

That's why we do have wake-from-USB but not powerup-from-USB. Chipsets that let you keep ONE single USB port enabled and power the others down don't exist.

 

[krotchy]

Originally posted by: rox1co
ah that makes sense, well i guess i'm keeping this keyboard for a very long time and i don't ever hold down more than 5 keys, lol

Well when your running forward+sideways+crouching+voice key+changing weapons in counterstrike you want all those keys to respond, hehe. Lets see thats just W-A-Ctrl-F-Q on my keyboard, I suppose you could try holding shift to walk to, if you really want to stress a keyboard, lol.

 

[rox1co]

lol well i play cs all the time and i've most likely pressed 5 keys at once and never had a problem

 

[vailr]

Originally posted by: Peter
Chipsets that let you keep ONE single USB port enabled and power the others down don't exist.

So, why doesn't some chipset maker produce a "dedicated: 'power on' (keyboard-only) USB port"?
No more PS2 ports! No more legacy: parallel or serial ports!

 

[Peter]

The problem is that you cannot simply separate one port from the others, since they all are in the same chip, and they all share the same EHCI controller unit for "High Speed" USB2 operation.

Besides, making one port "dedicated for keyboard/mouse" would exactly defeat the "U" in USB ("Universal")