Setting the MicroStation Aspect Ratio TechNote

MicroStation automatically detects the aspect ratio of the display screens on most systems. In some configurations (including some dual screen Windows displays), the video driver returns incorrect display size information, causing elements to appear stretched in either the horizontal or vertical direction. The MicroStation configuration variable MS_ASPECTRATIO specifies the correct aspect ratio to use in these situations (if your display is not distorted, there is no need to create this configuration variable). This variable should be set to the ratio of the width to the height of the display area.

For example:

System A: Display screen is 200mm wide by 150mm high. The aspect ratio is 200/150 = 1.33, so set MS_ASPECTRATIO=1.33.

System B: A dual screen system where each screen is the size of the System A display and the monitors are arranged side-by-side. The display area width is 400mm and the aspect ratio would be 400/150 = 2.67, so set MS_ASPECTRATIO=2.67.

Important Note: If MS_ASPECTRATIO is set as a system environment variable in AUTOEXEC.BAT, it will affect operation in both DOS and Windows 3.1x, potentially causing a problem in the version that receives correct information about the display size. Therefore, it is highly recommended that this variable only be set through the configuration variable dialog box of MicroStation (Workspace > Configuration > New dialog). The exact procedure follows:

1. Select Workspace > Configuration from the menu.
2. The Configuration dialog opens.
3. Select the New button. This will open the New Configuration Variable Dialog.
4. In the "Variable" field type MS_ASPECTRATIO.
5. In the "New Value" field type the value you calculated for your screens.
6. Select OK.
7. Restart MicroStation.
8. Your monitor should now display circles and squares correctly.

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