VERY IMPORTANT NOTICE: If you are using K6-2/3 (+) and RIVA TNT, TNT2, or Riva 128ZX (or even some other GPUs such as GeForce MX200) and you are experiencing crashes and freezing do the following:
1) in the bios "Write Cache Pipline" MUST be disabled
2) try to change "AGP Aperture Size" (start with 32Mb setting)
3) try to disable "Video Bios Shadow". The problem with "Write Cache Pipeline" is 100% prooved by more users - important!

Bios chip is soldered to the motherboard, make sure you use the bios for the right version of the motherboard.

Serial port silkscreen is wrong, (proven on rev 1.1A and 1.2A PCB) it reads like staggered:
13579
2468
but should be straight:
12345
6789
warning - do not use CTmouse driver to test it. This driver + some of the mice (for example LogiTech NetMouse) works in DOS even with the wrong pinout of the ribbon cable! Other mouse did not work. Non of the mice worked in Windows 98se.