I have problems with some strange glitches with different videocards and games.

for example i tried a 486 motherboard with a tseng labs et4000 card. while playing commander keen4 and keen6 on the first level, while moving.. there are some areas of the game that look fine, but some areas start to show artifacts on half the screen. If i keep moving the artifacts dissapear, if i return to the old place i was.. the artifacts appear again.

with a PCI S3 videocard diamond stealth 3d, i dont see artifacts but half of the scren has blinking shadow on half the screen. (kind of the same problem with the tseng but instead of artifacts its a dark blinking shadow on half the screen) in here i tried a different motherboard i think it was a pentium4

with another videocard i think it was S3 also cheaply made, i saw no problems in those games.

the strange part is that other games like Doom or Wolf3d show no problems at all on the screen.