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What are the performance indicators of cga, ega, and vga?

青灯夜游
青灯夜游Original
2020-12-25 14:22:1032154browse

Performance indicators of "graphics card". CGA (Color Graphics Adapter) is the computer display standard on the first IBM PC; VGA (Video Graphics Array) is a computer display standard using analog signals; EGA (Enhanced Graphics Adapter) is the IBM PC computer display standard definition, with performance between between CGA and VGA.

What are the performance indicators of cga, ega, and vga?

#The operating environment of this article: windows10 system, thinkpad t480 computer.

cga, ega, and vga are the performance indicators of "graphics cards".

  • CGA: Color graphics adapter, providing two standard text display modes: 40×25×16 colors and 80×25×16 colors; and two commonly used graphics display modes: 320 ×200×4 colors and 640×200×2 colors;

  • EGA: Enhanced graphics adapter, between CGA and VGA in terms of display performance (color and resolution), EGA The modes provided by the card include text and color graphics;

  • VGA: Video graphics array, which has the advantages of high resolution, fast display speed, rich colors, etc., and is widely used in the field of color displays. With a wide range of applications, VGA first referred to the display mode of 640×480 monitors.

Detailed introduction

CGA (Color Graphics Adapter)

Color Graphics Adapter (English: CGA, Color Graphics Adapter), is the first color graphics card launched by IBM in 1981, and is also the first computer display standard on IBM PC. The standard IBM CGA graphics card has 16 kilobytes of display memory. The CGA card provides a variety of graphics and text display modes, as well as a display resolution of up to 640×200, and a display capability of up to 16 colors (usually cannot be displayed at the maximum resolution). The usual display capability of CGA is to display up to 4 colors simultaneously at a resolution of 320×200, but there are many other methods to simulate displaying more colors.

CGA provides two standard text display modes: 40×25×16 colors and 80×25×16 colors; and two commonly used graphics display modes: 320×200×4 colors and 640×200×2 color.

With the development of computer technology, CGA was also replaced by the Enhanced Graphics Adapter (EGA, Enhanced Graphics Adapter) launched by IBM in 1984.

VGA (Video Graphics Array)

Video Graphics Array (English: Video Graphics Array, referred to as VGA) is a computer using analog signals proposed by IBM in 1987 Display standards. This standard is very outdated for today's PC market. Even so, VGA is still a standard supported by the most manufacturers, and personal computers must support the VGA standard before loading their own unique drivers. For example, the boot screen of Microsoft Windows series products still uses VGA display mode, which also shows that its resolution and color number are insufficient.

The term VGA is often used to refer directly to the resolution of 640×480 regardless of the graphics device. The VGA device can store 4 complete EGA color versions at the same time, and can quickly switch between them, making it look like an instant color change on the screen.

EGA (Enhanced Graphics Adapter)

Enhanced Graphics Adapter (Enhanced Graphics Adapter or EGA) is the IBM PC computer display standard definition, in terms of display performance (color and resolution degree) between CGA and VGA.

It is a technology introduced by IBM in 1984 for its new PC-AT computer. EGA can achieve 16 colors at resolutions up to 640x350. The EGA contains a 16KB read-only memory (ROM) to extend the system BIOS for additional display functionality and a Motorola MC6845 video address generator.

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