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APMSLEEP(1)									      APMSLEEP(1)

       apmsleep - go into suspend or standby mode and wake-up later

       apmsleep  [-sSnwhVd]  [--suspend]  [--standby]  [--noapm]  [--wait]  [--precise]  [--help]
       [--version] [--debug] [+]hh:mm

       Some computers, especially laptops, can wake-up from a  low-power  suspend  to  DRAM  mode
       using  the  Real-time-clock (RTC) chip.	Apmsleep can be used to set the alarm time in the
       RTC and to go into suspend or standby mode. An interrupt from the RTC causes the  computer
       to  wake-up.  The program detects this event, by waiting for a leap in the kernel time and
       terminates successfully. If no time leap occurs	within	one  minute,  or  something  goes
       wrong, the exit value will be non-zero.

       The wake-up time can be specified in two formats:

       +hh:mm  specifies  a  relative  offset  to the current time. The computer will suspend for
       exactly hh hours and mm minutes plus a few seconds to wake up.  On some laptops, the  tim-
       ing is not completely accurate so it may be a few minutes (or more?) late.

       hh:mm  specifies  absolute local time in 24-hour format. The time stored in the RTC is not
       important.  You may change the time zone used, with the TZ environment variable as  usual.
       Daylight  saving  time  is  not	obeyed in this version, but might be in a future release.
       WARNING: Do not close cover of laptop after suspending the  laptop  with  apmsleep.   Most
       laptops overheat when running with closed cover.

       Energy conservation with APM is little for a desktop. Turning of the screen will save 1/2,
       going into standby with drives turned off will save another 1/6th of the current.

       -V, --version
	      Print the apmsleep program version and exit immediately.

       -s, --suspend
	      Put the machine into suspend mode if possible (default). On my laptop, suspend mode
	      turns off everything except the memory.

       -S, --standby
	      Put the machine into standby mode if possible. On my laptop, standby mode turns off
	      screen, hard disk, and CPU.

       -w, --wait
	      Wait indefinitely for the time leap.

       -p, --precise
	      Wait for alarm time to match actual time. Do not wait for time leap.  This might be
	      useful even without APM.

       -n, --noapm
	      Do  not  call  apm  bios to suspend computer, just set the alarm clock and wait for
	      time leap indefinitely.

       -d, --debug
	      Print some information about what is going on.

       Kernel The special character device /dev/rtc must exist and the Linux kernel needs  to  be
	      compiled with APM and RTC support (CONFIG_RTC, and relevant CONFIG_APM* options).

       BIOS   The  computer  must have the 'suspend to RAM' feature enabled in the BIOS; 'suspend
	      to Disk' will not work, because the computer is turned off completely. You  do  not
	      need  to	enable the ALARM timer, it will be activated by apmsleep. On some boards,
	      you can configure which interrupts can be used to awake from suspend mode.  If  you
	      have  such  a board, you might want to make sure that keyboard (IRQ 1) and RTC (IRQ
	      8) are among those interrupts. If your computer does not wake  up,  try  to  enable
	      'modem ring' in the BIOS, even if you do not have a modem.

	      The program must be run as root or have the SUID attribute set (see chmod(1)).

       Apmsleep  cannot  detect  which event terminated the suspension. Possible events are: key-
       board or mouse activity, modem ring, alarm from RTC, any other interrupt.  Sometimes,  the
       time leap is not detected properly (causing a wrong exit value).

       Should use APM BIOS calls to set alarm clock (not yet supported by kernel).

       This  program  was  tested  on a Winbook XL laptop (Pentium) only.  It may not function on
       your hardware.

       Written by Peter Englmaier (ppe@mpe.mpg.de) and may be freely distributed under the  terms
       of  the GNU General Public License.  The code is based on Paul Gortmacher's RTC test/exam-
       ple program.  There is ABSOLUTELY NO WARRANTY for this program.	The current maintainer is
       Peter Englmaier.

       xapm(1), apmd(8),rtc.txt(Linux Kernel Documentation)

APM				sleep in APM suspend/standby mode		      APMSLEEP(1)
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