Screen Features

Size

Desktop screens are usually 15 - 23 in. by diagonal measurement. (This is how TV screens are measured, too.) Larger sizes are available, at a significantly higher cost. Prices are dropping, but you still have to have the space for a bigger screen.

Resolution

Determines how clear and detailed the image is. Pictures on a screen are made up of tiny dots. 1 dot on screen = 1 pixel (from "picture element") The more pixels per inch, the clearer and more detailed the picture. One measure of this is the dot pitch, the distance between the dots that make up the picture on the screen. However, different manufacturers measure differently. Most measure from dot center to the center of the nearest same color dot. Some measure from the center of a dot to an imaginary vertical line through the center of the nearest dot of the same color, giving a smaller number for the same dots as the previous method. Some monitors use skinny rectangles instead of dots and so must use a different method altogether. So, dot pitch has become less useful as a measure of monitor quality. A dot pitch of.28 is very common and.26 should be good for nearly all purposes, however it is measured.

Refresh Rate

CRT screens: How often the picture is redrawn on the monitor. If the rate is low, the picture will appear to flicker. Flicker is not only annoying but also causes eye strain and nausea. So, a high refresh rate is desirable. 60 times per second is tolerable at low resolutions for most people. 75 times per second or more is better and is necessary for high resolutions. (Does not apply to LCD screens)

Type

Old types = CGA, EGA, VGA
Current type = super VGA
Determines what resolutions are available and how many colors can be displayed.

Type	Stands for	Resolution(s)
CGA	Color Graphics Adapter	320 x 200
EGA	Extended Graphics Adapter	640 x 350
VGA	Video Graphics Adapter	640 x 480
SVGA	Super VGA	800 x 600, 1024 x 768, or 1280 x 1024 etc.

New systems now come with super VGA with a picture size of 800 x 600 pixels (as a minimum) and 16 million colors

Color

The number of colors displayed can vary from 16 to 256 to 64 thousand to 16.7 million. The more colors, the smoother graphics appear, especially photos. The number of colors available actually depends more on the video card used and on how much memory is devoted to the display. It takes 8 bits to describe 1 pixel when using 256 colors. It takes 24 bits per pixel when using 16 million colors. So a LOT of memory is needed to get those millions of colors. Video cards now come with extra memory chips on them to help handle the load.

Reverse video

example:

Cursor/ Pointer

The symbol showing where you are working on the screen, like: and In the olden days of just DOS, there were few choices for the cursor. The invention of the blinking cursor was a tremendous event. Really! Under Windows there are a huge number of basic to fantasy cursors to choose from.

Scrolling

Moving the lines displayed on the screen up or down one line at a time

Дата добавления: 2014-12-23