DIFFERENCES BETWEEN CHARACTER MODE :

DIFFERENCES BETWEEN CHARACTER MODE :
AND GRAPHICAL MODE:


In character mode the dot pattern of the each character is stored in the video memory chips. Usually they can allow 80 characters and 25 lines of characters.

Each character occupies fixed position on the screen, and the character always has the same font.

But it is faster then graphical mode as the size of the character is fixed. But it limits the number of characters that are supposed to be displayed on the screen.

In graphical mode, data is displayed one pixel at a time. A typical VGA display 640 pixels horizontally and 480 vertically.

But it is slower when compared to character mode because of the variable size of the characters.


DEVICE INDEPENDENCE:

Device Independence means that the program is able to work using different hardware like screens, keyboards and printers without any modifications to the program.

Windows provides this feature by using the Graphical Device Interface.


GRAPHICAL DEVICE INTERFACE:

The GDI is a layer between the application and the different types of the hardware.

Due to this architecture the programmer does not have to take the hardware into consideration whenever he is writing any application.

The Graphical Device Interface is a part of the windows that converts the Windows graphics to the actual commands sent t the hardware.

The GDI is a program file called GDI32.EXE that is stored in the system directory.

A device driver is a program that assists the GDI in converting Windows graphics commands to hardware commands.