I went through the entire ABit (tw) ftp site looking for anything kt20........... either it is so old that they don't even have records, or maybe there was a slip in the MoBo name you're calling out........... ??????
Afterthought: was this MoBo in a pre-assembled system? (compaq, HP, Dell, Gateway, etc.) If so, you will need to search around on the mfgr. site. (Good luck, most of them are pretty dismal when it comes to stuff like this)