Information and Communication Technology (1+1)

2.1.30 Display Screen 

When a text is keyed in, the screen (which is similar to a television screen) displays the characters. The user can read the text line by line and make corrections before it is stored or printed on a printer. It is also possible to display on the screen a portion of text stored in the external storage for purposes of reviewing and editing. The operator normally uses a cursor to pinpoint a particular position on the screen. The cu rsor can be moved along a line (in both the directions) or vertically from one line to another. This facilitates quick and easy editing. Screen sizes differ from system to system. The standard size is 24 lines by 80 characters. Most systems have provision for scrolling. This facilitates the user to move the text vertically on the screen, thus bringing to the screen the stored text. It is also possible to scroll horizontally. Thus the user can scan through the entire file either to review or to select a part icular portion. The cursor on the screen is controlled by cursor keys on the keyboard. The size and colour of the displayed characters and the colour of the screen should be carefully selected to avoid any glare and strain to the eyes.