As Andrew Webster wrote:

> The folks at APC also sell the *spec* on the communication protocol used 
> between the UPS and the PC.  For $50 and a signed N.D.A., they will send
> you a book describing how it works.

Hehehehe.  They are too late.  The Smart UPS protocol has been
re-engineered long ago.  You can get a working UPS daemon somewhere on
ftp.ww.net, there's a mailing list (upsd-list@ww.net), and the latest
package will ship on the FreeBSD 2.1.5 CD-ROM.  Alexis Yushin, the
author of upsd, did also make an official FreeBSD `port' out of it.

I'd instantly assume that zero to minor modifications would be
required to get it going on NetBSD.

-- 
cheers, J"org

joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)