It isn't possible as you describe it.  The only Alpha systems that
support this would be the 7000 and 8x00 "enterprise servers".  All
other *servers* use an option (KCRCM) that is implemented on the system
board for newer servers and as an ISA plug-in board for older servers
that interposes a microprocessor in the serial data stream that
watches for the magic key sequence then allows you to halt/reboot/
powerup/powerdown.  None of the workstations (and the AS200 is a
workstation) have the wiring needed to support this option.

I think the canonic answer here is to buy a UPS with a serial port
that supports remote powerup/powerdown commands.

-- 
Dave Cherkus ------- UniMaster, Inc. ------ Contract Software Development
Specialties: UNIX Internals/Kernel TCP/IP Alpha Clusters Performance ISDN
Email: cherkus@UniMaster.COM  When the music's over, turn out the lights!