Selector Light Pen Feature - IBM 3270 Operator's Manual

Selector Light Pen Feature
The selector light pen is a feature for a 3278 Display Station. You will usually
use the selector light pen to select one entry of a list of options or items dis-
played on the screen. Figure 4-1 shows the selector light pen and the keyboard
area in which you can place the light pen when not using it.
Figure 4-1. 3278 Selector Light Pcn
How It Works
The point of the pen contains a device that can detect the light of a character on
the screen. This device checks for the presence of a character only when a
switch, also located in the point of the pen, is activated. The switch is spring-
loaded and is activated by placing the point of the pen on the screen and pushing
the barrel of the pen toward the screen (Figure 4-2).
Figure 4-2. When the selector light pen is being used, correct
positioning of the tip of the pen is important.
Chapter 4. Features for the 3278 4-3