Raster Scan Display Vs Random Scan Display

Raster Scan Display	Random Scan Display
The electron beam scans the entire surface of CRT from top to bottom and from left to right with one row at a time.	The electron beam is directed only at those parts of the screen where a picture is to be drawn.
Picture definition is stored in frame buffer or refresh buffer as a set intensity values for all the screen points.	Picture definition is stored in display list or display file as a set of line drawing commands.
Refreshing occurs when the electron beam completes the entire scan or cycle and moves back to the top left corner of screen.	Refreshing occurs when all the line drawing commands are processed and system cycles back to the first command.
Refresh rate is independent of picture complexity. It is 60 to 80 cycles per second.	Refresh rate depends directly on picture complexity. It is 30 to 60 times per second.
A picture is displayed in form of pattern illuminated spots on the screen.	A picture is displayed in form of lines.
It has poor or less resolution as picture definition is stored as intensity values.	It has high resolution as picture is stored as a set of line drawing commands.
It produces jagged lines because plotted values are discrete.	It produces smooth lines as the electron beam directly follows the line.
It is suitable for displaying realistic images and scenes with different colors and shading patterns.	It is not suitable for realistic display as it cannot display shades. It is used for line drawing applications.
The concept of interlacing is used.	The concept of interlacing is not used.
10. Scan conversion is required.	10. Scan conversion is not required.
It uses shadow-mask method.	It uses beam penetration method.
It is less expensive than random scan system.	It is costlier than raster scan system.