If you have the gog.com version of The Settlers II just use it as is. If you have a CD-ROM version you need to use the following settings:
[cpu]
core=auto
cycles=max
cycleup=500
cycledown=500
[sdl]
fullscreen=true
fulldouble=false
fullresolution=original
windowresolution=original
output=ddraw
autolock=true
sensitivity=100
waitonerror=true
priority=higher,normal
mapperfile=mapper.txt
usescancodes=true
[render]
frameskip=0
aspect=true
scaler=normal2x
The most important settings are scaler which should be a simple one. Either normal2x or no scaler. The output should be ddraw or overlay in order to scale properly. For performance cycles need to be set to max.
