APM(3)                                                     APM(3)

     NAME
          apm - Advanced Power Management 1.2 BIOS interface

     SYNOPSIS
          bind -a #P /dev

          /dev/apm

     DESCRIPTION
          This device presents a low-level interface to the APM 1.2
          bios calls.  It is enabled by adding the line ``apm0='' to
          plan9.ini. (The value after the equals sign is ignored; the
          presence of the line at all enables the driver.)  It is only
          available on uniprocessor PCs.  Writing a 386 Ureg structure
          and then reading it back executes an APM call: the written
          registers are passed to the call, and the read registers are
          those returned by the call.

          This device is intended to enable more user-friendly inter-
          faces such as apm(8).

     SOURCE
          /sys/src/9/pc/apm.c
          /sys/src/9/pc/apmjump.s