Try here:
http://www.nvidia.com/object/linux_display_ia32_1.0-5336.html
There is a read me there too. I'm not familiar with Slackware but it is about the same regardless of distro, except Gentoo.
Note, if you have one of the new 64 bit CPUs, that won't work. You will need the IA64 version. Nvidia site, click downloads - drivers then IA64. Should take you right to it.
Hope that helps.
