APM (advanced power management) can be used to
turn off the hard disks and the screen to save power
and hardware life.

You may set the BIOS to monitor various events and to
bring the computer to sleep if none of them has occured
within a specified time.

If you set monitoring to mouse and keyboard only,
the Linrad will go to sleep after a while as specified
in the BIOS when you have not touched mouse or keyboard.

If you set APM to also monitor the parallel port Linrad
will run continously because Linrad will read the status 
port (0x379) now and then to tell APM it does not want 
to go to sleep. For this function to work you need 
permission to read the hardware port. Permission is 
given in users_open_devices() which is located in 
hwaredriver.c. 
If you use your own routine users_hwaredriver.c it is
your responsibility to get permission and set allow_parport
accordingly. The allow_parport flag is cleared in main.c
and it is used in modesub.c to decide whether to read 
the control port or not.

The default mode of operation is that the BIOS is set to
monitor keyboard, mouse and the parallel port but not
the hard disks. This way the computer will go to sleep
after the specified time when you exit Linrad.




 

