You need to install the packages b43-firmware-18.104.22.168-noarch-64.1.txz
After installing those packages you have to blacklist the modules b43
. Since Zenwalk is based on Slackware I would assume that you have a file blacklist.conf
. Edit this file as root and add the entries
Save the file and restart the system. Now you should be able to use the wireless. I don't know if Zenwalk has a network manager already installed, I would recommend wicd
if you don't have one.