I have an old T43 laptop by IBM. Recently I put Ubuntu 8.04 (Hardy) on it and started getting a hissing noise when running on battery power. I found 2 possible solutions:
add the following to /etc/modprobe.d/options
options processor max_cstate=2
get the linux-server kernel
sudo apt-get install linux-server
I didn’t get a chance to try the first option as I [...]