The doors on the front of the Crystal Scans and Vivitrons are opened by pushing near the top, then releasing. Some of the typical controls and what they do are listed below. These may or may not be present on your monitor. Monochrome monitors, for example, typically have only brightness and contrast controls. Brightness controls the amount of light given off by screen Contrast controls the difference in brightness from one screen color to the next.
Vertical size controls the height of the display area.
The maximum height is governed by the vertical size monitor screen. The vertical height should be adjusted to fit the display area between the upper and lower boundaries of the screen. Too little vertical height results in large areas of black at the top or bottom of the screen or both. Too much vertical height results in the display extending beyond the physical boundaries of the monitor screen and the loss of viewable information. Horizontal size controls the width of the display area.