Power supply program for AVR microcontrollers connected to LPT port
as described for the programs TwinAVR and SP12 

AvrPower.exe (Version 2.1)
This program uses direct hardware port access to the LPT and is
able to show always the real state of the LPT lines.
It runs under Windows 3.x, 9x and ME without problems. For NT
systems a hardware port driver such as UserPort.sys must be installed.
Bugfix: Now in systems with multiple LPT ports the LPT names
should be correct.

AvrPowerApi.exe (Version 3.0)
This program uses the NT-like API access to the LPT port without
any tricks. Therefore it should work under all conditions with
Windows 9x, ME and all NT systems such as NT4, Win2k and XP.
Not for use with Windows 3.x.
Disadvantage compared to AvrPower.exe: The program can't check
the real state of the power lines. Whenever another program or
power saving functions access the LPT the "Power" checkbox will
show an incorrect state. This isn't a problem but can disturbe a bit.