I thought you said you had a Pentium 133? A K-5 isn't up to a Pentium 133's speed. Your only hope would be a Voodoo 1 card. You can get a Monster 3D for $39 at CompUSA (after $30 rebate) or a Canopus Pure 3D (6mb) for $49 (www.purified3d.com - check the Canopus Pricewatch section).
But you'd really be wasting your time unless you just want to play games from a year or more ago. Your CPU is just about a doorstop now.