Video adapters

1
Video adapters

• Produce signals displayed by the monitor
• Text, images, video
• Black white and color
• Specialized processor chip-multiple operations
• Today they have more onboard memory perhaps even
  more than the CPU type or memory in your system.

2
Creating an image

• Phosphorescent coating A traditional TV style
  monitor creates an image when a stream of
  electrons hits a phosphorescent coating on the
  inside of the front screen.
• Electron beam In earliest monitors this coating
  would glow green in the presence of electron beam
  and black when it was not being hit with
  electrons , thence the green and black early
  monitors. Later red, green and blue.
• Refresh (scanning) rate The rate at which the
  image is painted on the screen .
• Interlacing In the early video display the full
  image could not be refreshed entirely in a single
  pass so odd lines of images were refreshed first
  then even ones refreshed on the second pass. Such
  interlaced displays often suffered badly from
  flickering.
• Resolution An image on the screen , be it text
  or image , is divided by the display adapter
  into a series of dots called PIXELS . Pixel is
  the smallest addressable unit of a picture. A
  monitors resolution id the number of pixels
  across and down that an adapter can create.
• Pixel depth (colors) -To create the full range ,
  or gamut , of colors you see, the display adapter
  must create and your monitor must be capable of
  showing many shades of each color. Such shades
  are determined by the intensity that each red,
  green or blue dot is made to glow. The number of
  shades that each component can be set to is
  determined by pixel depth or bits per pixel
  devoted to each shade.

3
Maximum colors
4
Video standards
5
SuperVGA

• No official standard
• Various proprietary schemes
• VESA BIOS Extensions (VBE)
• 640x400 at 8 bits per pixel
• 1600x1200 at 16 bits per pixel

6
15-pin VGA/SVGA connector
7
VGA/SVGA socket
8
DVI connector types
9
DVI-I connector (Digital Video Interface-I)
10
Video drivers

• Software interface between OS and video adapter
• Effect performance and operation
• Updated drivers
• Performance improvements
• Error fixes
• New features
• Use manufacturers driver not Windows
• Download from manufacturers Web site

11
Video adapter slot types

• Low-end built into motherboard
• High-end three types of slots
• PCI
• PCIe
• AGP
• PC slowest work well for two-monitor system
• AGP specialized for video
• PCIe designed to replace AGP

12
An AGP video card
13
PCIe video card