With a great deal of help from Steve Moret, Agetian and I have mangaged to figure out what those numbers mean in MapLimits.mes. First off, MapLimits.mes uses a non-isometric coordinate system that is separate from the isometric coordinate system used by the tiles. This coordinate system has the x axis horizontal, and the y axis vertical, with the intesection point (0,0) at the top center. (This will all make much more sense when you look at the attached diagram) The numbers in MapLimits.mes come in the format {x1, y1, x2, y2}, where x1 (always positive) is the leftmost boundary of the scrollable view window, X2 is the rightmost boundary, y1 is the top boundary, and y2 is the bottom boundary. I other words, these numbers form the coordinates of the box that the view window is allowed to scoll in, where (x1,y1) is the top left corner of the box, (x1,y2) is the bottom left corner, (x2,y1) is the top right, and (x2,y2)is the bottom right. In the diagram below I used the numbers {1020, -12544, -780, -14084} as they would appear in MapLimits.mes. Don't ask me why the x axis seems to be reversed, with the positive values to the left of the y axis and the negative values the the right. We just know this is how it is set up. The red arrow is some vector that Steve was talking about, which neither Agetian or myself fully understand. I hope this helps anyone who was puzzled by MapLimits.mes. Any questions?