Many people have tried to install the Broadcom WL adapter on a Laptop below Scientific Linux 6 already. With that small guide, I want to show you which way worked for me.
1.) Forget Broadcom's allround driver http://www.broadcom.com/support/802.11/linux_sta.php - it won't work!!! You won't be able to compile it on Scientific Linux 6.
2.) Update your Scientific Linux with the command "sudo yum update" first.
3.) Download http://pkgs.org/centos-6-rhel-6/atrpms-i386/broadcom-wl-5.100.82.38-5.el6.i686.rpm.html or http://pkgs.org/centos-6-rhel-6/atrpms-x86_64/broadcom-wl-5.100.82.38-5.el6.x86_64.rpm.html (it depends on what you will need for system: 32-bit or 64-bit).
4.) Look after the last installed vmlinuz version with the command "ls /boot/" or "dir /boot/". The last vmlinuz version in my case was (it is the highest number in the directory): vmlinuz-2.6.32-279.22.1.el6.x86_64 (I use a 64-bit architecture).
5.) Download the last WL-KMDL package for your vmzlinuz version and system, in my case it was: http://dl.atrpms.net/sl6-x86_64/atrpms/stable/broadcom-wl-kmdl-2.6.32-279.22.1.el6-5.100.82.38-5.el6.x86_64.rpm (that's a 64-bit version). As you can see, the correct vmlinuz version and architecture must appear in the file name here.
6.) Double click broadcom-wl-kmdl-<your vmlinuz version>-5.100.82.38-5.el6.<your architecture>.rpm first and then double click broadcom-wl-5.100.82.38-5.el6.<your architecture>.rpm. If you have downloaded the right versions, no error message should appear. Then restart your system and it should work.
7.) You will need to have to repeat the steps when "yum update" updated your kernel version of your Scientific Linux. Always. The broadcom driver doesn't get updated automatically and will get deactivated by the OS update then. You have to do the update of the broadcom driver by yourself. Fortunately, those are only a few steps.
Good luck!!!
