That is determined by the video card. Usually when setting brightness or constrast, one will get the Vertical Refresh frequency listed on the pop up screen of the monitor. Usually I set mine at 85Hz unless I am running in 1600 x 1200 video mode, which the monitor can only use with a Vertical Refresh (Refresh=XX) line of 60Hz. So to use 1600 x 1200 I must set the line in the ptw.ini or Civ3.Ini file to Refresh=60. Else it could be Refresh=85, but all video modes will work with Refresh=60, otherwise in 640 x 480 mode my Vertical Refresh=100, but 1024 x 768 mode only allows Refresh=85, and up to 1280 x 960 mode. Refresh=60 is a general all overall good refresh rate.
I can also set mine to Refresh=75 for all video modes except 1600 x 1200, then I must have it set at Refresh=60, but I think that Windows handled that once automically, since I was trying to play the game at 1600 x 1200 and had left the line at Refresh=85. It was not during the game but was at 60 instead. May depend on the OS system one is using.
Actually PTW jumps around too much in 1600 x 1200, now it jumps all the time, when others complained in CIv III that they had to move the screen. I rather move the freakin' screen than all the jumping around it does in PTW now at 1600 x 1200.
Actually pressing the Esc key, in the beginning of the Intro Movie will also Escape out of the opening movie to the game main entry screen. That is all I do now, when the Intro Movie starts, I simply press the Esc key to get out of it, afterall, may just want to watch it again. So I left the PlayIntro=1 line in the ptw.ini file after changing that to zero for awhile, probably just take it out, since I do not actually need it, at all!
Smiley goes here!