RTS --> cable --> Ring Indicator (RS232)

Can I use the RTS output signal to power up other pcs using the ring indicator available in most bioses ? Just by connecting the rts pin to a cable to the other pc ?

I have some self compiled c source code to turn the rts pin on. Would it work switching rts on, waiting a second and turning it off again ?

Probably - I've only powered up a computer once that way, and it seemed to startup as soon as it saw any activity on that line. It's probably easier to just do it then ask though...

Another way would be to just use the "wake-on-lan" feature. It's a lot more convenient than stringing a null-modem serial cable across just to wake it up. (Unless you don't have a LAN setup that is).

You are not "powering up" the PC, you are waking it up from a state. If you want to power it up, you need the POWER switch locked ON and something to control the AC power to the power supply.

If you want to wake it. LAN would be the best option. What OS are you running? How old in the motherboard?

I have 2 Pcs which do not support Wake on Lan running Debian and Windws 98.
Won't it work just activating the wake on modem ring in option in their bioses ?
I do not know about this option in Windows 98, though I've heard that for WOL you need to activate the option in the lan cards drivers. Is that necesarry for ring in too ?

WOL is hit and miss with older machines, and since you mention win98... I had some older 3Com cards that had a 3 pin header connected directly to the motherboard but that doesn't seem necessary with newer hardware.

You should probably just go ahead and try it - When I was messing around with it, I used a 9V battery and hooked it up to the RTS line of the serial port. No setup other than enabling it in BIOS. This was a couple years back, so I might be missing something though.

Why did you need the 9v battery ? I tought the rts line could be connected directly to the other com port.

I used the 9V to directly trigger the RTS line - no other computer.