You set your monitor's screen resolution, bits per pixel, and refresh rate with the Screen preference. You also use the preference to set the number of workspaces you want.
The top right popup menu lets you choose the scope of the settings you're about to apply. After you click Apply a dialog asks you to confirm your choice. If you don't confirm within about seven seconds, the screen reverts to its former settings.
You can adjust the refresh rate in .1 Hz increments by pressing the left and right arrow keys on the keyboard. When you adjust the refresh rate this way, the confirmation dialog doesn't appear.
You can adjust the size and position of the screen image by holding down Shift (to resize) or Control (to move) while pressing the arrow keys. The up and down arrows resize or move the screen vertically; the left and right arrows resize or move it horizontally.
Initially, BeOS displays a 640x480, 8-bit, 60.1 Hz screen. If your graphics card and monitor accommodate a higher resolution, more colors per pixel, or a faster refresh rate, you should change these settings.