i searched the web and found some manual here:
http://www.elhvb.com/mboards/adi/tk8881/index.html

however, the cpu settings section seems a bit short of explanations, and i couldn't find settings for following cpus:
intel dx4 standard
amd dx2 WT
amd dx4 WT
amd dx2 WB
amd dx4 WB
since this is a late 486 board with even amd5x86 listed, it should surely be aware of these cpus. which category shall these cpus fit into?