k after a litle googeling and tries i manage to make sim city 2000 work fast and good!
these are the configiration in the dosbox-0.73.conf changes that worked for my n900, for other devices it should be the same, but note your battery gonna suffer!

[line 53] frameskip=5 (was 0)
[line 75] cycles=max (was auto) these will probably kill your battery, so if you want leave it on auto, and increase the frameskip.
[line 87] nosound=true (was false)
[line 99] mpu401=none (was intelligent)
[line 122] sbtype=none (was sb16)
[line 147] gus=false (suppose to be false by default)
[line 164] pcspeaker=false (was true)

that's that
now you will have no sound (we need the speed for the game)
if you can try it and tell us the battery usesage please will

have fun!