M789 power loss restart

Alexander Amelkin spirit at reactor.ru
Sun Oct 17 11:05:00 CEST 2004

I  bought several M789 motherboards for my company to make Linux-based
routers.  The  boards  seemed very well suitable for such needs and we
previously used similar boards (787cl+ and others, not from PC Chips).

The HUGE problem is that the board does not support Power Loss Restart
function.  That  means  that  if power goes out, then our routers stop
working  and  never resume, even if the power returns. Our routers are
ususally  installed  in  places that are hardly reachable and it takes
several hours to bring them back up after the power outage. Power
outages are often that long that UPS can't handle it. Nobody cares of
it, because the outage usually covers the whole building or district.
However when the power returns to the building, people want their
Internet back. But the router is down due to no "power loss restart".

Previously with 787cl+ motherboard it helped to short-circuit the 14th
and  the  15th  pins  of  the ATX connector so the PSU stayed on. With
M789CLU  such  a  trick  does  not  work. The PSU stays on, but the MB
doesn't boot.

Does anybody know how can I make the board to be always on?
Is there any port register that I should write to?
Or is it a CMOS bit?

The board is built around VIA CLE266/VIA8235 chipset.

Thanks in advance for any hints.
Alexander Amelkin, MSCS
Head of hardware design dept.

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