Computer Cards

INTRODUTION

A computer card is an expansion device that provides an existing computer

with certain added capabilities. What these capabilities are depends of course on the

computer card. Some examples of popular computer cards include high speed serial

port cards, USB cards, firewire cards, and parallel cards. Widely varying both in size,

price, and purpose, these cards have the ability to make your computer perform

functions or connect with external previously.

Take the popular USB card for example. USB, or Universal Serial Bus, is name

given to a certain type of connective wire and port that can be used to transfer

information back and forth between computer, on the one hand, and an external device

such as a mouse, hard drive, or digital camera on the other. Many computers come with a

USB port already installed; a USB card, then, gives those computers without USB

capabilities a greater variety of possible ports, and it gives those computers that already

have USB ports an increased number of ports that they can use for other devices.

INTRODUCTION TO DIFFERENT TYPES OF CARDS

Introduction to different types of cards used in computer system is listed below:

Graphic cards

Sound cards

NIC cards

Video / T.V. Tuner cards

Serial / Parallel cards

Modem cards

USB cards

Firewire PCI cards

PCMCIA cardbus

Diagnostic cards

Graphics cards

A graphics card, video card, v card, video board, video display board, display adapter,

video adapter, or graphics adapter [1] is a computer component designed to convert the

logical representation of visual information into a signal that can be used as input for a

display medium. Displays are most often a monitor, but use of LCD TV, HDTVs, and

projectors is growing increasingly common with the growth of the media center computer

concept. The graphics card and display medium are able to communicate utilizing a

variety of display standards. Graphics cards are both integrated into motherboards, and

sold as expansion cards.

History

The original hardware accelerated 3D renderers came on a board that was used in

conjunction with a normal graphics card. The cards added 3D graphics to the 2D

rendering from the graphics card via a pass-through cable.

One of the major players in graphics card history was the Hercules Graphics Adapter

(HGC). It offered text mode of 80x25 and high quality monochromatic images of up to

720x348.

Card types

Integrated

In today's computer market, graphics cards are often substituted for an integrated

graphics chip on a section of the motherboard. Sometimes the graphics chip is located on

the Northbridge chip, if present, and uses either its own dedicated memory or more

usually a portion of the system memory (shared memory). Increasingly, it is possible to

select the amount of shared memory to be used via the BIOS. Integrated-graphics-

displays typically have inferior 3D performance compared to dedicated graphics cards

due to the use of cheaper chipsets and sharing system memory rather than using dedicated

memory. This is not always the case, as evidenced in higher-end integrated solutions,

such as game-oriented laptop architectures. Those who require high performance still

prefer non-integrated solutions.

Integrated graphics displays have gradually become more common in pre-built computer

systems since the mid 1990s as computer manufacturers such as Hewlett-Packard and

Dell look for ways to cut costs while still providing basic video support. In terms of

office tasks, web-browsing, email and similar computer activities, integrated graphics

displays are a more practical solution than high-powered 3D graphics cards. First person

shooter games like DOOM relied on high-performance cards at the time the game was

introduced.

Expansion

The most powerful graphics hardware, usually geared towards 3D graphics for games, is

typically found on expansio n cards. Their processing engines are sometimes called

GPUs (graphics processing units), or, most commonly used by ATI Technologies, VPU's

(Visual Processing Units). The longterm goal of graphics cards manufacturers (and game

developers) appears to be realtime photorealistic rendering. New products and

technologies are often touted to provide "Hollywood quality" - 3dfx used claims of

movie-quality effects to promote their Voodoo 5 cards with T-Buffer technology,

allowing motion blur, depth of field and full screen anti-aliasing effects. nVIDIA talked

about "the dawn of cinematic computing" when introducing its GeForce FX chip with the

Dawn technology demo. Others use the new technology for more stylised and unique but

unrealistic rendering, such as cel shading.

The most common connection for video cards for current mainboards is PCI Express,

which is taking over from the previous Accelerated Graphics Port, or AGP. Older video

cards used PCI which was more limited on bandwidth than AGP or PCI Express.

AGP is only allowed to send up to 35 watts of power to the video card using it, and

therefore some higher end cards required a seperate power connection. This was

supposed to be fixed when PCI Express was designed, with a maximum power raised to

75 watts. However, modern cards have now eclipsed that barrier, and therefore still

require a separate power connection.

What makes it fast?

Modern 3D graphics cards relay on the values of many variables in order to

determine their speed. The most important of these variables are; clock speed, memory

speed, and pixel processing volume.

The clock speed is the frequency with which the GPU or VPU operates at. This can be

anywhere in a large range and can be compared to the operating frequency of a CPU. The

memory clock is another way of determining how fast a card will operate. The memory

clock is also measured in Mhz (megahertz), but will sometimes have a theoretical

mutlipler associated with it. If your video card is operating with SDRAM then the

effective speed is the same at the clock speed. If you have DDR-SDRAM then the

effective frequency is twice that of the clock speed. For example, if you have an nVIDIA

6800gs with a 525Mhz memory clock, it effectively operates at 1050Mhz.

One very important card specification that is often overlooked is the number of pixel

pipelines. If a card has 8 pixel pipelines, a clock speed of 400Mhz, and a memory clock

of 1000Mhz, it if often slower than a card with 12 pipelines and lower clock amd

memory clock values. This is one of the main ways a consumer can tell where their card

falls in the spectrum of end-user graphics cards. Manufacturers can overclock their cards

without a problem; but they cannot add pixel pipelines, and therefore higher end cards

almost always have a higher pipeline count, allowing for higher volumes of data to be

processed and rendered.

There are other variables like memory architecture, and memory technology. Memory

architecture is normally a value of 128-bit, or 256-bit with the latter being on the higher

end, higher performance cards. Memory technology refers to the type of DDR-SDRAM

or SDRAM available. The highest end gaming graphics cards are using GDDR3 which

stands for Graphics Dual Data Rate Synchronous Dynamic RAM, Generation 3.

Uses

Conventional 2D

Conversely, sometimes 3D graphics capabilities are not relevant to the choice of high-

performance graphics card. The current generation of desktop software and operating

systems works exclusively with 2D graphics. Specialised niches in areas such as medical

imaging also require 2D graphics and fine visual-quality.

With the upcoming Windows Vista operating system, the images in the Windows OS will

be rendered by using vector graphics instead of bitmap graphics, or raster graphics.

Currently, this is a task that the CPU or Central Processing Unit of your pc is assigned to

complete. This new operating system will require that its main 2D graphics processing

will be taken over by the GPU or Graphics Processing Unit.

3D gaming and rendering

3D cards for model rendering in art and animation are different from those intended for

games. While they may have similar hardware, their drivers and firmware are optimized

for the specific task. Rendering cards are tuned for high precision, and gaming cards

provide high performance. A digital or analog monitor may be connected to the graphics

card via a DVI connector or VGA connector respectively. Increasingly, the higher end

cards offer dual DVI outputs for use with two or more digital displays, while maintaining

analog compatibility by bundling DVI-VGA converter dongles with the cards. Modern

first person shooters like F.E.A.R. have fairly high system requirements that require a

computer with a competent graphics card, enough RAM, and a fast enough CPU.

Graphics Card Basics

Think of a computer as a company with its own art department. When people in the

company want a piece of artwork, they send a request to the art department. The art

department decides how to create the image and then puts it on paper. The end result is

that someone's idea becomes an actual, viewable picture.

The four main components of a graphics card are connections for the motherboard and

monitor, a processor, and memory.

A graphics card works along the same principles. The CPU, working in conjunction with

software applications, sends information about the image to the graphics card. The

graphics card decides how to use the pixels on the screen to create the image. It then

sends that information to the monitor through a cable.

The Evolution of Graphics Cards

Graphics cards have come a long way since IBM introduced the first one in 1981. Called

a Monochrome Display Adapter (MDA), the card provided text-only displays of green or

white text on a black screen. Now, the minimum standard for new video cards is Video

Graphics Array (VGA), which allows 256 colors. With high-performance standards like

Quantum Extended Graphics Array (QXGA), video cards can display millions of colors

at resolutions of up to 2040 x 1536 pixels

Creating an image out of binary data is a demanding process. To make a 3-D image, the

graphics card first creates a wire frame out of straight lines. Then, it rasterizes the image

(fills the remaining pixels). It also adds lighting, texture and color. For fast-paced games,

the computer has to go through this process about sixty times per second. Without a

graphics card to perform the necessary calculations, the workload would be too much for

the computer to handle.

The graphics card accomplishes this task using four main components:

A motherboard connection for data and power.

A processor to decide what to do with each pixel on screen.

A memory to hold information about each pixel and to temporarily store complete

pictures.

A monitor connection so you can see final result.

Processor and Memory

Like a motherboard, a graphics card is a printed circuit board that houses a processor and

RAM. It also has an input/output system (BIOS) chip, which stores the card's settings and

performs diagnostics on the memory, input and output at startup.

A graphics card's processor, called a graphics processing unit (GPU), is similar to a

computer's CPU. A GPU, however, is designed specifically for performing the complex

mathematical and geometric calculations that are necessary for graphics rendering. Some

of the fastest GPUs have more transistors than the average CPU. A GPU produces a lot of

heat, so it is usually located under a heat sink or a fan.

A HEAT SINK or FAN which protects graphics processor from overheating

In addition to its processing power, a GPU uses special programming to help it analyze

and use data. ATI and nVidia produce the vast majority of GPUs on the market, and both

companies have developed their own enhancements for GPU performance. To improve

image quality, the processors use:

Full scene anti aliasing (FSAA), which smoothes the edges of 3-D objects

Anisotropic filtering (AF), which makes images look crisper

Each company has also developed specific techniques to help the GPU apply colors,

shading, textures and patterns. A brief description about graphic processor is given

below:

Graphics processor

Graphic processors are introduced on graphic cards itself. In this instead of sending a

raw screen image across to the frame buffer, the CPU sends a smaller set of drawing

instructions, which are interpreted by the graphics card’s proprietary driver and executed

by the card’s on-board processor.

Operations including bitmap transfers and painting, window resizing and repositioning,

line drawing, font scaling and polygon drawing can be handled by the card’s graphics

processor, which is designed to handle these tasks in hardware at far greater speeds than

the software running on the system’s CPU. The graphics processor then writes the frame

data to the frame buffer. As there’s less data to transfer, there’s less congestion on the

system bus, and the PC’s CPU workload is greatly reduced.

Each company has also developed specific techniques to help the GPU apply colors,

shading, textures and patterns.

As the GPU creates images, it needs somewhere to hold information and completed

pictures. It uses the card's RAM for this purpose, storing data about each pixel, its color

and its location on the screen. Part of the RAM can also act as a frame buffer, meaning

that it holds completed images until it is time to display them. Typically, video RAM

operates at very high speeds and is dual ported, meaning that the system can read from it

and write to it at the same time.

The RAM connects directly to the digital-to-analog converter, called the DAC. This

converter, also called the RAMDAC, translates the image into an analog signal that the

monitor can use. Some cards have multiple RAMDACs, which can improve performance

and support more than one monitor.

The RAMDAC sends the final picture to the monitor through a cable.

Video Memory

The memory that holds the video image is also referred to as the frame buffer and is

usually implemented on the graphics card itself. Early systems implemented video

memory in standard DRAM. However, this requires continual refreshing of the data to

prevent it from being lost and cannot be modified during this refresh process. The

consequence, particularly at the very fast clock speeds demanded by modern graphics

cards, is that performance is badly degraded.

An advantage of implementing video memory on the graphics board itself is that it can be

customized for its specific task and, indeed, this has resulted in a proliferation of new

memory technologies:

Video RAM (VRAM): a special type of dual-ported DRAM, which can be written to and

read from at the same time. It also requires far less frequent refreshing than ordinary

DRAM and consequently performs much better

Windows RAM (WRAM): as used by the hugely successful Matrox Millennium card, is

also dual-ported and can run slightly faster than conventional VRAM

EDO DRAM: which provides a higher bandwidth than DRAM, can be clocked higher

than normal DRAM and manages the read/write cycles more efficiently

SDRAM: Similar to EDO RAM except the memory and graphics chips run on a common

clock used to latch data, allowing SDRAM to run faster than regular EDO RAM

SGRAM: Same as SDRAM but also supports block writes and write-per-bit, which yield

better performance on graphics chips that support these enhanced features

DRDRAM: Direct RDRAM is a totally new, general-purpose memory architecture

which promises a 20-fold performance improvement over conventional DRAM.

Some designs integrate the graphics circuitry into the motherboard itself and use a

portion of the system’s RAM for the frame buffer. This is called unified memory

architecture and is used for reasons of cost reduction only. Since such implementations

cannot take advantage of specialized video memory technologies they will always result

in inferior graphics performance.

The information in the video memory frame buffer is an image of what appears on the

screen, stored as a digital bitmap. But while the video memory contains digital

information its output medium, the monitor, uses analogue signals. The analogue signal

requires more than just an on or off signal, as it’s used to determine where, when and

with what intensity the electron guns should be fired as they scan across and down the

front of the monitor. This is where the RAMDAC comes in picture.

What Makes a Good Graphics Card?

A top-of-the-line graphics card is easy to spot. It has lots of memory and a fast processor.

Often, it's also more visually appealing than anything else that's intended to go inside a

computer's case. Lots of high-performance video cards are illustrated or have decorative

fans or heat sinks.

But a high-end card provides more power than most people really need. People who use

their computers primarily for e-mail, word processing or Web surfing can find all the

necessary graphics support on a motherboard with integrated graphics. A mid-range card

is sufficient for most casual gamers. People who are game enthusiasts and people who

do lots of 3D work.

. Some cards, like the ATI All-in-Wonder, include connections for televisions and video

as well as a TV tuner

A good overall measurement of a card's performance is its frame rate, measured in frames

per second (FPS). The frame rate describes how many complete images the card can

display per second. The human eye can process about 25 frames every second, but fast-

action games require a frame rate of at least 60 FPS to provide smooth animation and

scrolling. Components of the frame rate are:

Triangles or vertices per second: 3-D images are made of triangles, or polygons. This

measurement describes how quickly the GPU can calculate the whole polygon or the

vertices that define it. In general, it describes how quickly the card builds a wire

frame image.

Pixel fill rate: This measurement describes how many pixels the GPU can process in a

second, which translates to how quickly it can rasterize the image.

The graphics card's hardware directly affects its speed. These are the hardware

specifications that most affect the card's speed and the units in which they are measured:

GPU clock speed (MHz)

Size of the memory bus (bits)

Amount of available memory (MB)

Memory clock rate (Mhz)

Memory bandwidth (GB/s)

RAMDAC speed (MHz)

The computer's CPU and motherboard also play a part, since a very fast graphics card

can't compensate for a motherboard's inability to deliver data quickly. Similarly, the

card's connection to the motherboard and the speed at which it can get instructions from

the CPU affect its performance.

Colour depthEach pixel of a screen image is displayed using a combination of three different colour

signals: red, green and blue. The precise appearance of each pixel is controlled by the

intensity of these three beams of light and the amount of information that is stored about

a pixel determines its colour depth. The more bits that are used per pixel ('bit depth'), the

finer the colour detail of the image.

The table below shows the colour depths in current use:

Colour depth DescriptionNo. of

colours

Bytes per

pixel

4-bit Standard VGA 16 0.5

8-bit 256-colour mode 256 1.0

16-bit High colour 65,536 2.0

24-bit True colour 16,777,216 3.0

For a display to fool the eye into seeing full colour, 256 shades of red, green and blue are

required; that is 8 bits for each of the three primary colours, hence 24 bits in total.

However, some graphics cards actually require 32 bits for each pixel to display true

colour, due to the way in which they use the video memory - the extra 8 bits generally

being used for an alpha channel (transparencies).

High colour uses two bytes of information to store the intensity values for the three

colours, using 5 bits for blue, 5 bits for red and 6 bits for green. The resulting 32 different

intensities for blue and red and 64 different intensities for green results in a very slight

loss of visible image quality, but with the advantages of a lower video memory

requirement and faster performance.

The 256-colour mode uses a level of indirection by introducing the concept of a ‘palette’

of colours, selectable from the entire range of 16.7 million colours. Each colour in the

256-colour palette is defined using the standard 3-byte colour definition used in true

colour: 256 possible intensities for each of red, blue and green. Any given image can then

use any colour from its associated palette.

The palette approach is an excellent compromise solution allowing for far greater

precision in an image than would be possible by using the 8 bits available by, for

example, assigning each pixel a 2-bit value for blue and 3-bit values each for green and

red. Because of its relatively low demands on video memory the 256-colour mode is a

widely used standard, especially in PCs used primarily for business applications.For

example, if a graphics subsystem is capable of handling 256 colours, and an image that

uses 65,000 colours is displayed, colours that are not available will be substituted by

colours created from combinations of colours that are available. The colour quality of a

dithered image is inferior to a non-dithered image.

DITHERING

Dithering also refers to a technique that uses two colours to create the appearance of a

third, giving a smoother appearance to otherwise abrupt transitions. In other words, it is

also a method of using patterns to simulate gradations of grey or colour shades, or of

anti-aliasing.

ResolutionResolution is a term often used interchangeably with addressability, but it more properly

refers to the sharpness, or detail, of the visual image. It is primarily a function of the

monitor and is determined by the beam size and dot pitch (sometimes referred to as 'line

pitch'). An image is created when a beam of electrons strikes phosphors which coat the

base of the monitor’s ‘screen’. A group comprising one red, one green and one blue

phosphor is known as a pixel. A pixel represents the smallest piece of the screen that can

be controlled individually, and each pixel can be set to a different colour and intensity. A

complete screen image is composed of thousands of pixels and the screen's resolution -

specified in terms of a row by column figure - is the maximum number of displayable

pixels. The higher the resolution, the more pixels that can be displayed and therefore the

more information the screen can display at any given time.

The greater number of colours, or the higher the resolution or, the more video memory

will be required. However, since it is a shared resource reducing one will allow an

increase in the other. The table below shows the possible combinations for typical

amounts of video memory:

Video memory ResolutionColour

depthNo. colours

1Mb1024 x 768

800 x 600

8-bit

16-bit

256

65,536

2Mb

1024 x 768

1280 x 1024

800 x 600

8-bit

16-bit

24-bit

256

65,536

16.7 million

4Mb 1024 x 768 24-bit 16.7 million

6Mb 1280 x 1024 24-bit 16.7 million

8Mb 1600 x 1200 32-bit 16.7 million

Even though the total amount of video memory installed may not be needed for a

particular resolution, the extra memory is often used for caching information for the

graphics processor. For example, the caching of commonly used graphical items - such as

text fonts and icons - avoids the need for the graphics subsystem to load these each time a

new letter is written or an icon is moved and thereby improves performance.

SOUND CARDS

A sound card is a computer expansion card that can input and output sound under control

of computer programs. Typical uses of sound cards include providing the audio

component for multimedia applications such as music composition, editing video or

audio, presentation/education, and entertainment (games).

Contents

1General characteristics

2 History

2.1 Hardware Manufacturers

2.2 Industry Adoption

2.3 Feature Evolution

3 Driver architecture

General characteristics

Close-up of a sound card PCB, showing electrolytic capacitors (most likely for AC

coupling), SMT capacitors and resistors, and a YAC512 two-channel 16-bit DAC

A typical sound card includes a sound chip, usually featuring a digital-to-analog

converter, that converts recorded or generated digital waveforms of sound into an analog

format. This signal is led to a (typically 1/8-inch earphone-type) connector where an

amplifier, headphones, or similar sound destination can be plugged in. More advanced

designs usually include more than one sound chip to separate duties between digital

sound production and synthesized sounds (usually for real-time generation of music and

sound effects utilizing little data and CPU time).

Digital sound reproduction is usually achieved by multi-channel DACs, able to play

multiple digital samples at different pitches and volumes, optionally applying real-time

effects like filtering or distortion. Multi-channel digital sound playback can also be used

for music synthesis if used with a digitized instrument bank of some sort, typically a

small amount of ROM or Flash memory containing samples corresponding to the

standard MIDI instruments. (A contrasting way to synthesize sound on a PC uses "audio

codecs", which rely heavily on software for music synthesis, MIDI compliance and even

multiple-channel emulation. This approach has become common as manufacturers seek

to simplify the design and the cost of the sound card itself.

Most sound cards have a line in connector where the sound signal from a cassette tape

recorder or similar sound source can be input. The sound card can digitize this signal and

store it (controlled by the corresponding computer software) on the computer's hard disk

for editing or further reproduction. Another typical external connector is the microphone

connector, for connecting to a microphone or other input device that generates a

relatively lower voltage than the line in connector. Input through a microphone jack is

typically used by speech recognition software or Voice over IP applications.

Most sound cards adhere to Microsoft's PC 99 standard for color coding the external

connections:

Colour Function

 Pink Analog microphone input.

 Light Blue Analog line level input.

 Lime

green

Analog line level output for the main stereo

signal (front speakers or headphones).

 Back Analog line level output for rear speakers.

 Orange S/PDIF digital output (sometimes used as an

analog line output for a center speaker

instead)

History

A sound card based on VIA Envy chip

Echo Digital Audio Corporation's Indigo IO — PCMCIA card 24-bit 96 kHz stereo in/out

sound card

Sound cards for computers based on the IBM PC remained uncommon until about 1988,

leaving the internal PC speaker as the only way early PC games could produce sound and

music. The speaker was limited to square wave production, leading to the common

nickname of "beeper" and the resulting sound described as "beeps and boops". Several

companies, most notably Access Software, developed techniques for digital sound

reproduction over the PC speaker; the resulting audio, while functional, suffered from

distorted output and low volume, and usually required all other processing to halt while

sounds were played. Other home computer models of the 1980s included hardware

support for digital sound playback or music synthesis (or both), leaving the IBM PC at a

disadvantage when it came to multimedia applications such as music composition or

gaming.

It is important to note that the primary design and marketing focus of sound cards for the

IBM PC platform were not based on gaming, but rather on specific audio applications

such as music composition (AdLib Personal Music System, Creative Music System, IBM

Music Feature Card) or on speech synthesis (Digispeech DS201, Covox Speech Thing,

Street Electronics Echo). It took the involvment of Sierra and other game companies in

1988 to switch the focus toward gaming.

Hardware Manufacturers

One of the first manufacturers of sound cards for the IBM PC was AdLib, who produced

a card based on the Yamaha YM3812 sound chip, aka the OPL2. The AdLib had two

modes: A 9-voice mode where each voice could be fully programmed, and a lesser-used

"percussion" mode that used 3 regular voices to produce 5 independent percussion-only

voices for a total of 11. (The percussion mode was considered inflexible by most

developers, so it was used mostly by AdLib's own composition software.)

Creative Labs also marketed a sound card at the same time called the Creative Music

System. Although the C/MS had twelve voices to AdLib's nine, and was a stereo card

while the AdLib was mono, the basic technology behind it was based on the Philips SAA

1099 which was essentially a square-wave generator. Sounding not unlike twelve

simultaneous PC speakers, it never caught on the way the AdLib did, even after Creative

marketed it a year later through Radio Shack as the Game Blaster. The Game Blaster

retailed for under $100 and included the hit game title Silpheed.

Probably the most significant historical change in the history of sound cards came when

Creative Labs produced the Sound Blaster card. The Sound Blaster cloned the AdLib,

and also added a sound coprocessor to record and play back digital audio (presumably an

Intel microcontroller, which Creative incorrectly called a "DSP" to suggest it was a

digital signal processor), a game port for adding a joystick, and the ability to interface to

MIDI equipment (using the game port and a special cable). With more features at nearly

the same price point, and compatibility with existing AdLib titles, most first-time buyers

chose the Sound Blaster. The Sound Blaster eventually outsold the AdLib and set the

stage for dominating the market.

The Sound Blaster line of cards, in tandem with the first cheap CD-ROM drives and

evolving video technology, ushered in a new era of multimedia computer applications

that could play back CD audio, add recorded dialogue to computer games, or even

reproduce motion video (albeit at much lower resolutions and quality). The widespread

adoption of Sound Blaster support in multimedia and entertainment titles meant that

future sound cards such as Media Vision's Pro Audio Spectrum and the Gravis

Ultrasound needed to address Sound Blaster compatibility if they were to compete

against it.

Industry Adoption

When game company Sierra Entertainment (known then as Sierra On-Line) opted to

make music for add-on hardware instead of utilizing the built in PC-speaker, the concept

of PC sound and music changed dramatically. The two companies Sierra eventually

started to cooperate with were Roland and Adlib. Sierra opted to make in-game music,

starting with King's Quest 4, for the Roland MT-32 and Adlib Music Synthesizer. The

MT-32 was far superior as it boasted a synthesizer that could combine small wave

samples with synthesized sounds, and it had excellent reverb. Sierra really made the most

of the MT-32, and nearly every game loaded custom patches onto the synth to produce

sound effects for things like birds chirping and horses clopping in the age before the

Sound Blaster brought the possibility of playing such things as audio clips to the PC

world. The MT-32 was able to deliver much better sound reproduction than the FM chip

residing in the Adlib soundcard. The popularity of MT-32 lead the way for the adoption

of MPU-401/Roland Sound Canvas and General MIDI standards as the definitive means

of playing in-game music until mid-1990s.

Feature Evolution

Most ISA bus soundcards could not record and play digitized sound simultaneously,

partially due to lack of available hardware interrupts and DMA channels, and partially

due to inferior card DSPs. Later PCI bus cards fixed these limitations and are mostly full-

duplex.

For years, soundcards had only one or two channels of digital sound (most notably the

Soundblaster series and their compatibles) with the notable exception of the Gravis

Ultrasound family, which had hardware support for 14 to 32 independent channels of

digital audio, and early games and MOD-players had to fully emulate multiple channels

by software downmixing. Today, most good quality sound cards have hardware support

for at least 16 channels of digital audio, but others, like those that utilize cheap Audio

codecs, still rely partially or completely on software through either device drivers or the

operating system itself to perform a software downmix of multiple audio channels.

In the late 1990s, many computer manufacturers began to replace plug-in soundcards

with a "codec" (actually a combined audio AD/DA-converter) integrated into the

motherboard. Many of these used Intel's AC97 specification. Others used cheap ACR

slots.

As stated before, these "codecs" usually lack the hardware for direct music synthesis or

even multi-channel sound, with special drivers and software making up for these lacks, at

the expense of CPU speed (for example, MIDI reproduction takes away 10-15% CPU

time on an Athlon XP 1600+ CPU).

Driver architecture

To use a sound card, a certain operating system typically requires a specific device driver.

DOS programs had to code the sound hardware directly or use universal middleware

sound libraries (HMI Sound Operating System, Miles Sound System etc.) which had

drivers for most common sound cards, although some manufacturers provided their

own (pretty inefficient) middleware TSRs.

Microsoft Windows uses proprietary drivers supplied by sound card manufacturers

and supplied to Microsoft for inclusion in the distributions. Sometimes drivers are

also supplied by the individual vendors for download and installation.

The Linux kernel used in the Linux distributions have two different driver

architectures,the OpenSound System and ALSA (Advanced Linux Sound

Architecture). Both include drivers for most cards by default. Sound card

manufacturers seldom produce stand-alone drivers for Linux.

The Universal Serial Bus (USB) specification defines a standard interface for sound

cards to adhere to, the USB audio device class, allowing a single driver to work with

the various USB sound cards on the market.

Before the invention of the sound card, a PC could make one sound - a beep. Although

the computer could change the beep's frequency and duration, it couldn't change the

volume or create other sounds.

At first, the beep acted primarily as a signal or a warning. Later, developers created music

for the earliest PC games using beeps of different pitches and lengths. This music was not

particularly realistic -- you can hear samples from some of these soundtracks at Crossfire

Designs.

PC sound card

Fortunately, computers' sound capabilities increased greatly in the 1980s, when several

manufacturers introduced add-on cards dedicated to controlling sound. Now, a computer

with a sound card can do far more than just beep. It can produce 3-D audio for games or

surround sound playback for DVDs. It can also capture and record sound from external

sources.

In this article, you'll learn how a sound card allows a computer to create and record real,

high-quality sound.

Before the invention of the sound card, a PC could make one sound - a beep. Although

the computer could change the beep's frequency and duration, it couldn't change the

volume or create other sounds.

At first, the beep acted primarily as a signal or a warning. Later, developers created music

for the earliest PC games using beeps of different pitches and lengths. This music was not

particularly realistic -- you can hear samples from some of these soundtracks at Crossfire

Designs.

Digital signal processors

A card’s sound generator is based on a custom DSP (Digital Signal Processor) that

replays the required musical notes by multiplexing reads from different areas of the wave

table memory at differing speeds to give the required pitches. The maximum number of

notes available is related to the processing power available in the DSP and is referred to

as the card’s ‘polyphony’.

DSPs use complex algorithms to create effects such as reverb, chorus and delay. Reverb

gives the impression that the instruments are being played in large concert halls. Chorus

is used to give the impression that many instruments are playing at once when in fact

there’s only one. Adding a stereo delay to a guitar part, for example, can ‘thicken’ the

texture and give it a spacious stereo presence.

Sampling and recordingWhen a sound card records analogue audio, it is converting the sound waveform into

digital information and then copying this in real time onto the hard disk. Essentially, it is

using the disk as a digital tapeless recorder. To hear what’s been recorded, the sound card

takes the digital information off the hard disk, converts it back into analogue, and then

feeds it to loudspeakers, headphones or a conventional sound recorder.

The process of converting analogue to digital is known as digitalizing or sampling. With

the analogue waveform is chopped into a number of slices per second. At each slice, the

amplitude is measured and rounded to the nearest available value. Clearly the more chops

per second (sampling rate) and the finer the values assignable to the amplitude (dynamic

range), the better the representation of the original.

CD digital employs a sampling rate of 44.1kHz and a 16-bit dynamic range. That is,

44,100 chops every second, each one describing the waveform amplitude at that moment

in time with a 16-bit number; 16-bit itself offering 65,536 steps from which to choose. Of

course, CD is a stereo system so that means two 16-bit words every 44,100th of a second.

That works out at around 160KBps, 10.5MB/min or 630MB/hour. The most common file

format used to store digital audio on PCs is WAV.

All sound cards should offer up to 16-bit resolution and sampling rates of 44.1kHz or

48kHz, although they will also operate at lower quality settings for less demanding

circumstances. Superior sound cards boast lower noise levels and higher-quality

analogue-to-digital and digital-to-analogue converters.

Recording and editing audio uses a large amount of hard disk space, with ten minutes’

CD quality requiring over 100MB. The faster the disk and I/O sub-system the better

when working with such large files. Modern hard disks and PCI controllers are capable of

sustaining a transfer of at least 4MBps. Serious practitioners will want to ensure that

there are no interruptions in the audio stream. Many hard disks pause, to thermally

recalibrate, which can result in a short but undesirable pause. Some A/V drives are

specifically designed not to thermally recalibrate, thus eliminating this effect.

For those wanting nothing but the best, nothing can match the virtually loss-less quality a

completely digital audio processing system can offer. However, since the digital-only

market is small and specialized and with few competitors, this currently comes at a price.

The principal components of an all-digital system are a sound card equipped with S/PDIF

(Sony/Philips Digital Interface) format Digital In and Digital Out sockets and software to

transfer digital audio onto a hard disk. The CD Grab Professional utility is an example of

the latter capable of copying digital information directly off a CD-ROM drive onto a hard

disk in 16-bit stereo 44.1kHz WAV format

TYPES OF SOUNDS AVAILABLE IN THE MARKET

NIC CARDS (NRTWORK INTERFACING CARDS)

INTRODUCTION

A network interface card, more commonly referred to as a NIC, is a device that allows

computers to be joined together in a LAN, or local area network. Networked computers

communicate with each other using a given protocol or agreed-upon language for

transmitting data packets between the different machines, known as nodes. The network

interface card acts as the liaison for the machine to both send and receive data on the

LAN.

The most common language or protocol for LANs is Ethernet, sometimes referred to as

IEEE 802.3. A lesser-used protocol is Token Ring. When building a LAN, a network

interface card must be installed in each computer on the network and all NICs in the

network must be of the same architecture. For example, all must either be Ethernet cards,

Token Ring cards, or an alternate technology.

An Ethernet network interface card is installed in an available slot inside the computer.

The NIC assigns a unique address called a MAC (media access control) to the machine.

The MACs on the network are used to direct traffic between the computers. The back

plate of the network interface card features a port that looks similar to a phone jack, but is

slightly larger. This port accommodates an Ethernet cable, which resembles a thicker

version of a standard telephone line. Ethernet cable must run from each network interface

card to a central hub or switch. The hub or switch acts like a relay, passing information

between computers using the MAC addresses and allowing resources like printers and

scanners to be shared along with data.

A network interface card does not have to be hard wired with physical cable. Wireless

Ethernet cards are installed like their wired counterparts, but rather than a port for an

Ethernet cable, the card features a small antenna. The card communicates with the central

wireless switch or hub via radio waves. Wireless LANs may have some restrictions

depending on the material the building is made from. For example, lead in walls can

block signals between the network interface card and hub or switch.

When buying components for a LAN, make sure the NICs and hub or switch have the

same capabilities. The entire network must be either wired or wireless, so a wireless

network interface card cannot talk to a wired switch or hub. In addition, newer versions

of hardware will likely support more features and/or greater speeds than older versions.

Make sure your central switch or hub can utilize the highest capabilities of the network

interface card under consideration.

For those who wish to connect LANs located in different areas of the city, state or

country, ATM (asynchronous transfer mode) can create wide area networks or WANs by

connecting LANs together. LANs are still built with a network interface card in each

networked computer, but ATM uses broadband Internet access to link the LANs to online

ATM switches. This type of ATM WAN is referred to as an Internet work.

Installation process for NIC cards

Once you have installed your network interface card in your PC, you should configure it.

Configuring an Ethernet card, such as the Danpex or Intel card, means telling the card a

couple of things about how it is to communicate with your computer and its operating

system.

Configuring the network interface card on a DOS or Windows 3.1-based PC can be

difficult. The extent of difficulty will depend on how many other devices, such as sound

cards, CDs, and game adapters you have installed. Those using (link)Windows 95 and

those using the (link)parallel port Ethernet adapter are less likely to encounter problems.

There is a setup/configuration program on the disk that came with the network card. The

program is in the \setup directory and is called netsetup. In order for this program to run

properly, you must not have installed any software drivers for the network card: If you

have just installed the card and have done nothing else, then you most likely have not yet

installed any software driver for it. Run this program from the DOS prompt.

Place the disk in the A: drive (or B: drive, if that is the 3 ½-inch drive on your computer)

and make the A: drive the current drive by entering A: at the DOS prompt.

C:\> A: Make the A: drive the current drive

A:\> cd setup Change to the setup directory

A:\SETUP> netsetup Run the configuration/setup program

Select 2420x from the list

Ethernet Board ID Screen

The next screen will be similar in appearance to the first, but with just one item. The

screen will be titled "Ethernet Board ID Selection" and will indicate that the program has

found your network interface card. If so, the card will be listed as Board 1. Following

that will be the settings for three attributes Node ID, I/O Base, and IRQ. We are interested

in the settings for I/O Base and IRQ. (The Node ID is pre-set and is unique for each card.)

Press the <Enter> key to continue on from this screen.

Ethernet Board ID Selection

Board 1: Node ID=0040c711cae1, I/O Base= 300, IRQ= 3

The Danpex boards come with the I/O Base set to a value of 300 and the IRQ set to a

value of 3. Normally, I/O Base value of 300 does not conflict with other devices and we

typically do not change it. The IRQ value of 3, however, may cause a conflict if you are

using two serial devices, such as a serial mouse and a modem. If you do not need to

change either of these values, then press the <Escape> key to exit from the

configuration/setup program. If you need to change one of them, then press the <Enter>

key to continue on with the program.

Function Menu Main

The Main Function menu is the next to appear. Select the entry Change Configuration

using the up or down arrow key and then press the <Enter> key.

Change Configuration Menu

On the Change Configuration menu, select Set Configuration A. The entries for both I/O

Base and IRQ are on the Set Configuration A menu as IOADDR and IRQ respectively.

Use the up or down arrow key to highlight the value you want to change and press the

<Enter> key to select it. Follow the same process to select a new value for the item

selected. If you change the value for either I/O Base or IRQ you must make sure that it

does not conflict with another device in your computer. We often use an I/O Base value

of 300 and an IRQ value of 10 as a starting point. In most cases the I/O Base of 300 does

not conflict with anything else; on PCs with several additional devices there may be IRQ

conflicts with both 3 and 10. In the latter case you will need to experiment or contact

Campus Computing either at extension 2616 or at support

Exit from Menu Screens and Program

To exit from each level of configuration screen, press the <Escape> key. Exit from the

program and return to DOS. If there are no resource conflicts, your computer hardware is

network-ready. You need to go to Mac Hall and fill out one of the (yellow) CATNET

application forms ("Application for a Network Address on CAT NET in Linfield

Residence Halls") available in the hallway near the PC and Macintosh labs. Drop the

form in the box provided.

Various kinds of NIC cards available in the market with their specifications:

Network Interface Cards

7 Port Gigabit LAN, USB 2.0, FireWire Combo PCI

Card Ref-UNI7068-2 Multi-interface expansion on a single PCI card! Multi-interface expansion on a single PCI card!

10/100/1000Base-T Gigabit Ethernet port 3 x USB 2.0 ports 3 x FireWire (IEEE1394) ports 4 Pin FireWire port for use with digital camcorders/cameras Compatible with Windows

7 Port, Fast Ethernet 10/100 LAN/USB 2.0/FireWire PCI Combo Card Ref-UNI176

Multi-interface expansion on a single card! Multi-interface expansion on a single card! Using only a single PCI slot, this feature packed combo card allows you to add Fast Ethernet, FireWire and USB 2.0 connections without the need to purchase separate dedicated cards. This combo card is a cost effective and versatile solution for users who wish to connect to the latest high-speed peripherals, and add network functionality too!

PCI (32 Bit) Ethernet UTP/BNC Card Ref: UNI70939 "Plug & Play" networking!This card is finished to a high standard to allow for easy and safe installation, and it is backed by the full UK technical support service. The finger contacts are gold-plated to limit oxidization and extend the life of the card.

 

PCI (32 Bit) Fast Ethernet 10/100 Card Ref: UNI70953

Fully configurable!Fully configurable!

This card is finished to a high standard to allow for easy and safe installation, and it is backed by the full UK technical support service. The finger contacts are

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gold-plated to limit oxidization and extend the life of the card.

PCI (32 Bit) Gigabit Ethernet 10/100/1000 Card Ref: UNI70969

Gigabit Ethernet over standard CAT5e cables!This card is finished to a high standard to allow for easy and safe installation, and it is backed by the full UK technical support service. The finger contacts are gold-plated to limit oxidisation and extend the life of the card.

 

Wireless LAN PCI Card - 802.11g, 54Mbps Ref: UNI52011

Connect your desktop PC to your Wireless LAN!Connect your desktop PC to your Wireless LAN!

Complies with the IEEE 802.11g and IEEE 802.11b standards High data transfer rate - up to 54Mbit/sec 64/128/152-bit WEP Data Encryption function for high level of security Supports IEEE 802.1x advanced WLAN Security

Supports peer-to-peer communication among any wireless users, no Access Point required External dipole antenna with long length cable for optimal positioning Automatic fallback increases data security and reliability Compatible with Windows 98SE/ME/2000/XP

PCMCIA (16 Bit) Fast Ethernet 10/100 Adapter Ref: UNI70983-1

Attach your laptop or notebook to a 10/100Mbps network!Attach your laptop or notebook to a 10/100Mbps network!

Bus Type: 16 Bit PCMCIA (CardBus Compliant) Speed: 10/100Mbit/sec, Auto-sensing

Standard: IEEE 802.3 (10Base-T) & IEEE 802.3u (100Base-TX) I/O Address: “Plug & Play” IRQ Selection: “Plug & Play” Card Connector: RJ-45 STP/UTP (10/100Base-TX) Software Compatibility: Windows 98SE/ME/NT/2000/XP and NDIS 3.0, 4.0  

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VIDEO CARDS

Your system's video card is the component responsible for producing the visual output

from your computer. Virtually all programs produce visual output; the video card is the

piece of hardware that takes that output and tells the monitor which of the dots on the

screen to light up (and in what color) to allow you to see it.

Like most parts of the PC, the video card had very humble beginnings--it was only

responsible for taking what the processor produced as output and displaying it on the

screen. Early on, this was simply text, and not even color at that. Video cards today are

much more like coprocessors; they have their own intelligence and do a lot of processing

that would otherwise have to be done by the system processor. This is a necessity due to

the enormous increase both in how much data we send to our monitors today, and the

sophisticated calculations that must be done to determine what we see on the screen. This

is particularly so with the rise of graphical operating systems, and 3D computing.

What does a Video Card do, what affects the performance?

We have to realize that the data as soon as it leaves the CPU has to go through 4 steps

until it finally reaches the monitor:

From the bus into the Video Chipset, where it's processed (digital data)

From the Video Chipset into the Video Memory, to store a mirror of the screen

picture here (digital

data)

From the Video Memory into the Digital Analog Converter (= RAM DAC), to

read out the screen

mirror and convert it for the monitor (digital data)

From the Digital Analog Converter to the Monitor (analog data)

As you can see, except the step from the RAM DAC to the monitor, each step is

some kind of a bottleneck and crucial for the overall performance of the graphical

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subsystem. The slowest step is the one which determines the overall speed. Lets

now discuss, what these single steps mean and what actually happens:

The transfer of data between CPU and the Video Chipset

This bottleneck is mainly depending on the bus type and speed, the mainboard and its

chipset. The fastest bus system at present is the PCI bus, so you will have slower

performance with VL bus, ISA, EISA and NuBus (only for Macs). The PCI bus however

doesn't always run at highspeed of 33 MHz, so with a Pentium 75, P90, P120, P150 you'll

have a PCI bus speed of only 25 (P75) or 30 Mhz, which already here decreases the

performance of the graphical subsystem. Later chipsets also offer faster PCI performance,

so the Intel 430HX chipset offers a faster PCI performance than the Intel Triton 430FX

chipset. As the name already says, it's not a bus, it's a port. This means you can only run

one device on it, the graphic device. It can runs at 66 MHz and can tranfer data at the

rising and falling edge of a clock circle (x2 mode). This makes it at least double as fast as

PCI, but this does not necessarily result in double performance of AGP graphic cards,

because the data transfer bandwidth is not the limiting factor of current graphic cards.

The transfer of data between Video chipset to Video RAM and from Video RAM to the RAM DAC

I have been taking these two steps together because here lies the key for the performance

of a video card as long as you exclude special chipset features. The big problem of a

video card is that the poor video memory lies in between two very busy devices and has

to serve both of them all the time. Each time the screen has to change the chipsets has to

alter the video memory (and it changes continuously, e.g. mouse pointer, cursor blinking,

etc.). Also the RAM DAC has to read out the video memory continuously, to maintain

the screen. You can see, the video memory is caught in between them and here all these

smart ideas like using VRAM, WRAM, MDRAM, SGRAM, EDO RAM, or increasing

the video bus size like 32 bit, 64 bit and now 128 bit come in.

The higher the screen resolution and the higher the colour resolution, the more data has to

be transferred from the video chipset to the video memory and the faster the data has to

be read by the RAM DAC to be sent to the monitor. You can see that the video memory

has to be accessed all the time by the chipset and the RAM DAC. Normal dynamic RAM

can only be accessed at a max. frequency, so after the video chipset finished accessing

(r/w) the video memory, the RAM DAC has to wait until it's allowed to read and vice

versa.

The Video card manufacturers found three different ways to solve this problem:

1. Here comes the idea in, to make the video RAM dual ported. This means, that the

video chipset reads or writes from/to the video memory via one port, but the RAM DAC

reads out the video memory through an independent second port. The video chipset

doesn't have to wait for the RAM DAC anymore and the RAM DAC doesn't have to wait

for the video chipset anymore. This kind of video memory is called VRAM. It's

obviously more complicated by having double the ports and therefore more expensive to

produce. That's the simple reason why VRAM cards are more expensive and also faster.

The WRAM used by Matrox and a few other cards is also dual ported, but organised

somehow smarter so that it's faster than VRAM but also 20% cheaper to produce. If you

should wonder why typically cards which offer a high refresh rate and high colour depth

have these two kinds of memory, you should consider the following. A higher refresh rate

means that the RAM DAC feeds the monitor with a complete screen picture more often

than at a lower refresh rate. Therefore the RAM DAC has to read out the video memory

more often. This only can be achieved with either VRAM/WRAM, by accessing the

video memory via the second port, or by a considerable decrease of video performance of

DRAM/EDO cards. If you don't believe it, just run your favourite video benchmark at a

low and then at a high refresh rate - you'll see a considerable difference if you've got a

DRAM/EDO card. The same is valid for a higher colour depth. At a 8 bit colour

resolution (=256 colours) a 1024x768 screen needs 786,432 bytes to be read by the RAM

DAC to send a complete screen picture to the monitor. At 24 bit colour resolution

(16,777,216 colours) the same screen needs 2,359,296 bytes to be read by the RAM DAC

- and this takes more time. This btw is also the reason why you often can't have the same

high refresh rate at true colour as you had at low colour in cheaper cards.

2.  The other way to fight this problem is to increase the video memory bus size. Years

back everybody was amazed by the new 32 bit video cards. These cards had a 32 bit data

path between video chipset, video memory and RAM DAC. With 32 bit data path you

can transfer 4 bytes in one go. Later there came the 64 bit video cards = 8 byte in one go,

which are the standard at present and only recently some new chipsets were born, to have

a 128 bit data path = 16 byte in one go. It's easy to see, that video cards with both

(VRAM/WRAM & wide data path) will be the best performers, but with a really wide

data path you could get around VRAM/WRAM. Now by getting completely excited

about these wide data paths we shouldn't forget one very important thing: a normal

8x1Mbit memory chip, as used on most video cards has a data bus of 32 bits !!! Therefore

even a 128 bit chipset can access this memory chip only 32 bit wide !!! This is the reason

why all 64 bit video cards are a lot slower if only fitted with 1 MB of video RAM ! Don't

get a 64 bit video card with less than 2 MB !!!! Chipsets with 128 bit data path usually

need at least 4MB local memory, otherwise their performance is cut in half. The NVidia

Riva chipset e.g. is able to talk to only 2 MB as well, via a 64 bit data path. Riva cards

with only 2 MB are therefore castrated. However, due to the architecture of the card you

won't use 128 bit data path even if you upgrade to 4 MB, because the data path just stays

the same. This is probably the case in many video cards, so be careful not getting a 1 MB

64 bit card or a 2 MB 128 bit card!

3. The third and to us maybe most obvious way to get the video RAM accessed faster is

to simply increase the clock speed of the video chipset/video RAM/RAM DAC. Years

back the video chipsets ran at clock speeds high above the mainboard memory bus speeds

already. SGRAM is nowadys running at 100 MHz clock and some graphci chip

manufacturers are already talking of 125 or even 133 MHz video RAM clock using 7 ns

SGRAM. SGRAM is nothing but a special graphics version of SDRAM (synchronous

DRAM), so we know this is able to run at clock speeds up to 133 MHz.

Summarizing all these performance aspects, we learn that for optimal performance we

should have an AGP or at least PCI system with the latest chipset and 33 MHz PCI bus

speed, a video card with a high performance chip and either SGRAM or WRAM, a wide

data path or a high clock frequency of the video chipset or best all these three things

together!

Now which parts of this video card/monitor-combo plays which role?

The Monitor plays a crucial role in terms of sharpness, brightness, stability and max.

screen resolution of the picture. If you want to have a high quality picture you're asking

for a high quality monitor with a big screen, at least 17". Your video card can be as good

as it wants, as long as the monitor is crap the screen will still look horrible.

On the video card side, the RAM DAC is the part that is responsible to send the data for a

decent picture to the monitor. Two factors are important, the quality of the RAM DAC,

e.g. is it stand alone or integrated into the video chipset, and the max. pixel frequency,

measured in MHz. A 220 MHz RAM DAC is not neccessarily but most likely better than

a 135 MHz one and it certainly offers higher refresh rates - will tell you why further

down on this page. RAM DACs tend to be included into the graphic chips more and more

now, since it can decrease costs of graphic cards considerably and the quality of modern

internal RAM DACs is coming close to the external ones.

The Amount of Video RAM is responsible for the colour resolution in combination with

the screen resolution in 2D, in 3D, which is getting more and more important, the amount

of local card memory is also determining the maximal 3D resolution. 3D needs much

more local memory than 2D for the same resolution. This is due to the fact that 3D needs

a front, a back and a Z-buffer. The front buffer holds what you see, the back buffer holds

the next picture while it's being processed and the Z-buffer holds the 3rd dimension value

(z-value, as x and y make two dimensions, z holds the third). That is the reason why a

card with 4 MB local memory can offer a resolution of 1600x1200 at high color (16 bit)

in 2D, because it needs 1600x1200x2 byte = 3.7 MB. However games that are using z-

buffer information (and the good ones do, offering you real 3D) can only run at 800x600

x 16 bit color x 16 bit z-buffer, 800x600x6 byte (2 byte color front buffer, 2 byte color

back buffer, 2 byte 16 bit z-buffer) = 2.74 MB. 3D at 1024x768 would require 4.5 MB

and can't be displayed by a 4 MB 3D card.

The Type of Video RAM in combination with the Video Chipset is responsible for all

performance aspects of the video card/monitor-combo. However we shouldn't forget that

the bus system (PCI/VL/ISA/EISA/MCA/NuBus) and therefore also the mainboard and

the mainboard chipset are responsible for how fast the data reaches the video card. AGP,

the advanced graphic port can offer much higher transfer bandwidth than PCI.

The video card in your system plays a significant role in the following important aspects of your computer system:

Performance: The video card is one of the components that has an impact on system

performance. For some people (and some applications) the impact is not that

significant; for others, the video card's quality and efficiency can impact on

performance more than any other component in the PC! For example, many games

that depend on a high frame rate (how many times per second the screen is updated

with new information) for smooth animation, are impacted far more by the choice of

video card than even by the choice of system CPU.

Software Support: Certain programs require support from the video card. The

software that normally depends on the video card the most includes games and

graphics programs. Some programs (for example 3D-enhanced games) will not run at

all on a video card that doesn't support them.

Reliability and Stability: While not a major contributor to system reliability, choosing

the wrong video card can cause problematic system behavior. In particular, some

cards or types of cards are notorious for having unstable drivers, which can cause a

host of difficulties.

Comfort and Ergonomics: The video card, along with the monitor, determine the

quality of the image you see when you use your PC. This has an important impact

on how comfortable the PC is to use. Poor quality video cards don’t allow for

sufficiently refresh rates causing eyestrain and fatigue.

UNACCELERATED AND ACCELERATED VIDEO CARDS

The video card is only one part of the equation that determines what you see on your

screen. It is in a way the "middle man", working between the processor and the monitor.

The monitor, of course, is what actually provides the display that you see. The processor

computes and thus determines what you are going to see. A conventional video card does

the job of translating what the processor produces into a form that the monitor can

display.

Older video cards did this translation only; they were rather dumb in that they could only

take what the processor created and send it to the monitor. The processor did all of the

work of deciding what would be displayed. This was fine for older environments like

DOS, and especially for text-based output where the amount of information involved was

small. When graphical operating systems like Windows became the norm, suddenly large

amounts of data were being shuffled around on the screen, and the CPU was spending a

lot of time moving windows around, and drawing boxes and cursors and frames. As a

result the processor would often get bogged down and performance would decrease--

dramatically.

To clear this bottleneck companies began making cards called accelerators; in fact,

Windows drove this effort so much that they were often called Windows accelerators.

These were video cards that added smarts to enable them to do much of the video

calculating work that had been previously done by the processor. With an accelerator,

when the system needs to draw a box on the screen, it doesn't compute where all the

pixels need to be and what color, it sends a request to the video card saying "draw a

window at these locations" and the video card does it. The processor can then go on to do

more useful work. The accelerator, for its part, can be highly customized and tailored to

this specific job, and therefore be far more efficient at it than the processor.

This offloading of video calculation work has led to a many-fold increase in the power of

the video subsystem in a modern PC. Virtually all modern video cards incorporate

acceleration, some of it quite sophisticated. In essence, the video card becomes a

coprocessor, working with the main CPU. Continuing the trend, new 3D accelerators are

becoming more common, which offload the (tremendously time-consuming) work of 3D

animation from the processor as well.

THE VIDEO CHIPSET

Virtually all modern video cards are accelerators, which perform various video

calculation functions in addition to just providing the output signal to the monitor. The

capabilities of the video card are a function of the internal processor on the card that does

the calculating functions (as well as the more mundane tasks that every video card must

perform). The logic circuit that controls the video card is referred to as the video chipset.

It is sometimes also called an accelerator or video coprocessor.

Normally the word "chipset" refers to the system chipset that controls the motherboard.

The video chipset performs an analogous function for the video card. Motherboards

perform various functions that once required a myriad of individual chips; in later years

these functions were integrated into a small set of chips and called the "chipset". The

same thing has occurred with video cards. In fact, many (if not most) video chipsets are

actually a single chip.

There are two different approaches taken in the industry by video card makers. Some

manufacture their own video cards in their entirety, including designing the chipset logic

themselves. For example, Matrox designs their own cards from the ground up, which

gives them more control over the design and better ability to write efficient BIOSes and

software drivers. Other major card makers use third-party chipsets that they incorporate

into cards of their own design. For example, Diamond Multimedia uses chipsets made by

other companies such as S3. You can use this procedure to find out the exact name and

version of your video chipset.

INSTALLATION T.V TUNER CARD

Connect the T.V. Tuner card in motherboard on pci slot.

Then start the computer.

After starting Windows you will find new hardware that is T.V. Tuner card, then

click on next.

Then select the option last that is “specific location”, click on “Browse”, then insert

the driver cd of that card.

First install directx, then set appropriate path from cd for install installing the driver,

and then click on next. Some process will begin then click on next and last click on

“finish”, and then ask for the restart of your PC.

After starting your PC, if you want to check the card is installed perfectly or not for

that first right click on my computer then select “ device manager” , select the T.V

Tuner and right click on it,click on property of T.V Tuner card.

Then see the message in property Windows is “ this device is working properly”.

What's the difference between a graphics/video card, video capture card, and video editing card?

All PCs have a video card which is also called a graphics card. The graphics card is what

you plug your monitor/screen into. The video card fits into the AGP or PCI slot of the

motherboard, depending on what type of graphics/video card you have. (Some cheaper

PCs have the video card integrated into the motherboard). 

Video capture and video editing cards are additional cards. They  co-exist with the

graphics card. Video capture cards are cheaper than video editing cards. They provide

you with a socket for your camcorder. Some of them provide you with plugs for both

analogue (S-Video/composite) and digital (DV) camcorders. With analogue capture cards

you want to enquire whether they have both input and output sockets. (Digital connectors

can both send and receive video clips, analog connectors do either sending or

receiving). Video capture cards are generally bundled with some video editing software -

nothing as beefy as Liquid Edition or Adobe Premiere - but more along the lines of

ULead's Video Studio.

Video editing cards have specialist hardware built into the cards. This hardware is

dedicated to video editing work (e.g. rendering and MPEG encoding). The better video

editing cards are real-time editing cards. Many of them can handle in five minutes what a

fast modern PC would otherwise take an hour. Most people see video editing cards as

very expensive but we see them as free. Yes, free... :-)

When you pay £500 for a good video editing card the chances are that in addition to the

card, cables, manuals etc you are also getting a professional video editing software

package that would normally cost £500-£600 on its own, like Adobe Premiere making the

real price you are paying for the card = £0.

Do I need to have a special type of video card in addition to the video editing card?

The video card has very little - if anything - to do with video editing. What the video card

does is processes and sends video output signals to your monitor. Ideally you don't want

the cheapest, most basic video card in a video editing PC. But you don't need the latest all

singing and all dancing video card either.. Go for something in-between (unless you do

also want to play high end games on this PC). 

However, it is useful to have features like dual-head support (also called twin head, dual

monitor, hydra vision etc) which allows you to plug two monitors into your video card

thus doubling your screen real estate. You'll enjoy working with videos when you can

spread your work over two screens. You'll find you have a lot of little windows open and

if you have two screen you won't have to keep shutting down some windows to see

others. This saves so much of time it's unbelievable. With monitors becoming cheaper by

the day there's no excuse to have only one screen. Another useful feature to have is TV

Out via an S-Video socket. This allows you to connect a TV set to the PC to be used as a

monitor.

Video Editing card

A video editing card is a computer expansion card that allows the connection of a digital

or analog source of video to a computer for the purpose of importing video into the

computer and editing it. These cards often have dedicated hardware for the express

purpose of handling the rendering of video streams. Some of these cards offer real-time

video editing.

Manufacturers like Matrox, Pinnacle Systems and Canopus produce PCI video editing

cards. Pinnacle also produced an AGP version that doubled up as a standard graphics

card. All the manufacturers are now attempting the transition to PCI-Express versions of

their cards.

MODEM CARD

A modem (a portmanteau word constructed from modulator and demodulator) is a device

that modulates a carrier signal to encode digital information, and also demodulates such a

carrier signal to decode the transmitted information. The goal is to produce a signal that

can be transmitted easily and decoded to reproduce the original digital data.

In simpler terms, a modem is that box that flashes and goes "Bee-boo, bee-boo" when

you turn on your computer.

The most familiar example of a modem turns the digital '1s and 0s' of a personal

computer into sounds that can be transmitted over the telephone lines of Plain Old

Telephone System (POTS), and once received on the other side, converts those sounds

back into 1s and 0s. Modems are generally classified by the amount of data they can send

in a given time, normally measured in bits per second, or "bps".

Far more exotic modems are used by internet users every day. In telecommunications,

"radio modems" transmit repeating frames of data at very high data rates over microwave

radio links. Some microwave modems transmit more than a hundred million bits per

second.

Optical modems transmit data over optic fibers. Most intercontinental data links now use

optic modems transmitting over undersea optical fibers. Optic modems usually use

interferometric filters called etalons to separate different colors of light, and then

individually turn the pulses of each color of light into electronic digital data streams.

Optical modems routinely have data rates in excess of a billion (1x109) bits per second.

Their bandwidths are currently limited by the thermal expansion of the etalons; heat

changes an etalon's size and thus its frequency.

Modems can be used over any means of transmitting analog signals, from driven diodes

to radio.

Modems work by translating the digital signals from your computer into analogue signals

to transfer along the telephone lines and doing the opposite when recieving data.

This segment begins with an introduction followed by the classification of modems

according to their characteristics. Later, standards and protocols are discussed.

Finally, the document overview today's status and future trends.

The need to communicate between distant computers led to the use of the existing phone

network for data transmission. Most phone lines were designed to transmit analog

information - voices, while the computers and their devices work in digital form - pulses.

So, in order to use an analog medium, a converter between the two systems is needed.

This converter is the MODEM which performs MODulation and DEModulation of

transmitted data. It accepts serial binary pulses from a device, modulates some property

(amplitude, frequency, or phase) of an analog signal in order to send the signal in an

analog medium, and performs the opposite process, enabling the analog information to

arrive as digital pulses at the computer or device on the other side of connection.

Modems, in the beginning, were used mainly to communicate between DATA

TERMINALS and a HOST COMPUTER. Later, the use of modems was extended to

communicate between END COMPUTERS. This required more speed and the data rates

increased from 300 bps in early days to 28.8bps today. Today, transmission involves data

compression techniques which increase the rates, error detection and error correction for

more reliability.

In order to enable modems of various types and different manufacture to communicate,

interface standards were developed by some standard organizations

Today's modems are used for different functions. They act as textual and voice mail

systems, facsimiles, and are connected or integrated into cellular phones and in notebook

computers enabling sending data from anywhere. The future might lead to new

applications. Modem speeds are not expected to be increased much over today's 28.8

kbps. Further dramatic speed increases will require digital phone technology such as

ISDN and fiber optic lines.

New applications might be implemented such as simultaneous voice and data.

Videophones are an example of this.

CLASSIFICATION OF MODEMS

The modems can be classified according to their characteristics:

Range

1. Sort Haul

2. Voice Grade

3. Wideband

Line Type

1. Leased

2. Private

Operation Mode

1. Half Duplex

2. Full Duplex

3. Simplex

Synchronization

1. Asynchronous

2. Synchronous

Classifying Modems according to range:

Short Haul

Short haul modems are cheap solutions to systems of short ranges (up to 15 km), which

use private lines and are not part of a public system. Short haul modems can also be used,

even if the end-to-end length of the direct connection is longer than 15 km, when both

ends of the line are served by the same central office in the telephone system. These lines

are called "local loops". Short haul modems are distance-sensitive, because signal

attenuation occurs as the signal travels through the line. The transmission rate must be

lowered to ensure consistent and error-free transmission on longer distances.

Short haul modems tend to be cheaper than other modems for two reasons:

(1) No circuitry is included in them to correct for differences between the carrier

frequency of the demodulator and the frequency of the modulator.

1. (2) Generally no circuitry is included to reduce/correct for noise rejection, which

is less of a problem over short distances than over long distances.

Voice Grade (VG)

Voice-grade modems are used for unlimited destination, using a moderate to high data

rate. These modems are expensive and their maintenance and tuning are sophisticated.

Communication channels are leased lines and dial-up.

Voice-band telephone network is used for data transmission. A user-to-user connection

may be either dedicated or dialed. The links in the connection are the same in the two

cases, and the only difference for the user is that for some impairments (particularly

attenuation and delay distortion), a dedicated (private or leased) line is guaranteed to

meet certain specifications, whereas a dialed connection can only be described

statistically.

Wideband

Wideband modems are used in large-volume telephone-line multiplexing, dedicated

computer-to-computer links. These modems exceed high data rates.

Classifying Modems according to : Line Type

Leased, Private

Leased, private or dedicated lines (usually 4-wire) are for the exclusive use of "leased-

line" modems - either pair (in a simple point-to-point connection) or several (on a multi

drop network for a polling or a contention system). If the medium is the telephone

network, their transmission characteristics are usually guaranteed to meet certain

specifications, but if the link includes any radio transmission, the quality of it may be as

variable as that of a switched (i.e. nondedicated) line.

Dial-up

Dial-up modems can establish point-to-point connections on the PSTN by any

combination of manual or automatic dialing or answering. The quality of the circuit is not

guaranteed, but all phone companies establish objectives. The links established are

almost always 2-wire because 4-wire dialing is tedious and expensive.

Two and Four-Wires Lines

A four-wire (4W) line is a pair of two-wire (2W) lines, one for transmitting and one for

receiving, in which the signals in the two directions are to be kept totally separate. Perfect

separation can be maintained only if the four-wire configuration is sustained from

transmitter to receiver. The lines may be combined in a 4W/2W network (often called a

hybrid or a hybrid transformer) at any point in the signal path. In this case impedance

mismatches will cause reflections and interference between the two signal

Classifying Modems according to : Operation Mode

Half Duplex

Half duplex means that signals can be passed in either direction, but not in both

simultaneously. A telephone channel often includes an echo-suppressor, allowing

transmission in only one direction, this renders the channel half-duplex. Echo suppressors

are slowly being replaced by echo cancelers, which are theoretically full-duplex devices.

When a modem is connected to a two-wire line, its output impedance cannot be matched

exactly to the input impedance of the line, and some part of its transmitted signal (usually

badly distorted) will always be reflected back. For this reason half- duplex receivers are

disabled (received data is clamped) when their local transmitter is operative.

Half-duplex modems can work in full-duplex mode.

Full Duplex

Full duplex means that signals can be passed in either direction, simultaneously. Full

duplex operation on a two-wire line requires the ability to separate a receive signal from

the reflection of the transmitted signal. This is accomplished by either FDM (frequency

division multiplexing) in which the signals in the two directions occupy different

frequency bands and are separated by filtering, or by Echo Canceling (EC).

The implication of the term full-duplex is usually that the modem can transmit and

receive simultaneously at full speed. Modems that provide a low-speed reverse channel

are sometimes called split-speed or asymmetric modems.

Full duplex modems will not work on half-duplex channels.

Simplex

Simplex means that signals can be passed in one direction only. A remote modem for a

telemetering system might be simplex and a 2-wire line with a common unidirectional

amplifier is simplex.

* Echo Suppressor and Echo Canceler

At the junction between the local loop, which is usually a 2-wire circuit, and the trunk,

which is a 4-wire circuit, echoes can occur. The effect of the echo is that a person

speaking on the telephone hears his own words after a short delay. Psychological studies

have shown that this is annoying to many people, often making them stutter or become

confused. To eliminate the problem of echoes, echo suppressors are installed on lines

longer than 2000 km. (On short lines the echoes come back so fast that people cannot

detect them). An echo suppressor is a device that detects human speech coming from one

end of the connection and suppresses all signals going the other way. The device

compares the levels at its two input ports, and if it decides, for example that the other end

is talking, it inserts an attenuator in the return (echo) path, and vice versa.

Echo suppressors have several properties that are undesirable for data communication.

First, they prevent full- duplex data transmission, which would otherwise be possible,

even over the 2-wire local loop (by allocating part of the bandwidth to the forward

channel and part to the reserve channel). Even if half-duplex transmission is adequate,

they are a nuisance because the time required to switch directions can be substantial.

Double-talking totally confuses them, and the attenuation may be switched in and out

repeatedly. Furthermore, they are designed to reverse upon detecting human speech, not

digital data.

To reduce these problems, when echo suppressors detect a specific tone they shut down,

and remain shut down as long as the carrier is present (this is an example of inband

signaling, where control signals that activate and deactivate internal control functions lie

within the band accessible to the user). This disabling is usually done during initial

handshaking by one modem transmitting an answer tone in either 2100 Hz (CCITT

standard) or 2225 Hz (modems following the old Bell 103 standard).

Echo suppressor are slowly being replaced by ECs, which allow a certain amount of

double-talking and do not require "capture" time for any one talker to assume control of

the connection.

Establishing Connection

Establishing a connection between two modems involves a handshaking process of

sending and receiving coded signals to coordinate the connection. The FallBack method

is used to find a common way of communication. The calling modem first tries to

connect at its highest speed (or best error-correction or data compression scheme). If the

called modem doesn't signal back that is can handle that protocol, the calling modem falls

back to a slower speed or less effective scheme and tries to connect again. This cycle

continues until a common ground is found or they run out of options.

TODAY'S STATUS and FUTURE TRENDS

Today in addition external modems, there are internal modems which are included as an

additional board within the computer. There are advantages to each type.

Actual transfer rates are limited due to type of phone lines. Using slower phone trunks,

international circuits where half the normal bandwidth is used, and the slow cellular

connections where it might run at only 14.4 kbps (without compression) although the

modem itself enable 28.8kbps.

More and more users are accessing the Internet and on-line services such as Compuserve,

so, use of modems has increased dramatically. The more powerful processors such as

Pentium and PowerPC in workstations and PC's, enable the modem h/w to be less

complicated. Part of the functions done in the DSP or microcontroller might be

performed by the host. So, modems might drop in price.

The advent of semiconductor modems will enable a wide range of applications to be

implemented: Vending machines will call up when they need more goods to vend, or

elevators will call when they require service, and so on.

The last approved standard of V.34 with 28.8 kbits/s speed will enable the Digital

Simultaneous Voice and Data (DSDV) applications. DSVD is a modem specification

Installation of MODEM Card

Connect Modem on pci slit on the motherboard.

Then start computer, when a window is starting at that time a new hardware will

found it will be a modem card.

Then click on next.

Then select the option last that is “ specific location”, then click on “ browse”.

Then insert driver cd of the moden card in cd drive , then select the appropriate path

from cd for installing the driver of that modem card, then click on next.

After that some process will begin that process will be the installation of modem

driver , then click on next. At last click on “finish” , for completing the driver

installation process.

SERIAL / PARALLEL CARD

ISA (8/16 Bit) Serial RS-232 Card, 4 Port Serial 16C650 32 Byte FIFO, Interrupt Sharing 

The finger contacts are gold-plated to limit oxidization and extend the life of the card.This card is finished to a high standard to allow for easy and safe installation, and it is backed by the full technical support service. The finger contacts are gold-plated to limit oxidization and extend the life of the card.

Low Profile PCI (32 Bit) Serial RS-232 Card, 2 Port Serial 16C650 32 Byte FIFO 

The finger contacts are gold-plated to limit oxidization and extend the life of the card.This card is finished to a high standard to allow for easy and safe installation, and it is backed by the full technical support service. The finger contacts are gold-plated to limit oxidization and extend the life of the card.

PCI (32 Bit) Serial RS-232 Card, 1 Port Serial 16C650 32 Byte FIFO 

The finger contacts are gold-plated to limit

oxidization and extend the life of the card.This card is finished to a high standard to allow for easy and safe installation, and it is backed by the full technical support service. The finger contacts are gold-plated to limit oxidization and extend the life of the card.

PCI (32 Bit) Serial RS-232 Card, 8 Port Serial 16C650 32 Byte FIFO   The finger contacts are gold-plated to limit oxidization and extend the life of the card.This card is finished to a high standard to allow for easy and safe installation, and it is backed by the UK full technical support service. The finger contacts are gold-plated to limit oxidization and extend the life of the card.

PCI (32 Bit) Serial RS-232 Card, 2 Port Serial 16C650 32 Byte FIFO The finger contacts are gold-plated to limit oxidization and extend the life of the card.This card is finished to a high standard to allow for easy and safe installation, and it is backed by the full technical support service. The finger contacts are gold-plated to limit oxidization and

extend the life of the card.

PARALLEL CARDS

ISA (8/16 Bit) Parallel Card, 1 Port Parallel BPP/SPP 

The finger contacts are gold-plated to limit oxidization and extend the life of the card.This card is finished to a high standard to allow for easy and safe installation, and it is backed by the full uk technical support service. The finger contacts are gold-plated to limit oxidization and extend the life of the card.

ISA (8/16 Bit) Parallel Card, 3 Port Parallel ECP/EPP/BPP/SPP 

The finger contacts are gold-plated to limit oxidization and extend the life of the card.This card is finished to a high standard to allow for easy and safe installation, and it is backed by the full uk technical support service. The finger contacts are gold-plated to

limit oxidization and extend the life of the card.

PCI (32 Bit) Parallel Card, 1 Port Parallel ECP/EPP 

The finger contacts are gold-plated to limit oxidization and extend the life of the card.This card is finished to a high standard to allow

for easy and safe installation, and it is backed by the full uk technical support service. The finger contacts are gold-plated to limit oxidization and extend the life of the card.

ISA (8/16 Bit) Parallel Card, 2 Port Parallel ECP/EPP/BPP/SPP  

The finger contacts are gold-plated to limit oxidization and extend the life of the card.This card is finished to a high standard to allow for easy and safe installation, and it is backed by the full uk technical support service. The finger contacts are gold-plated to limit oxidization and extend the life of the card.

ISA (8/16 Bit) Parallel Card, 1 Port Parallel ECP/EPP/BPP/SPP  

The finger contacts are gold-plated to limit oxidization and extend the life of the card.This card is finished to a high standard to allow for easy and safe installation, and it is backed by the full uk technical support service. The finger contacts are gold-plated to limit oxidization and extend the life of the card.

DIAGNOSTIC CARDS

DIFFERENT KINDS OF DIAGNOSTIC CARDS AVAILABLE ARE GIVEN BELOW:

PCI (32 Bit) POST Code Diagnostic Card

Display visually POST hardware error codes!

POST Code Diagnostic card allows you to display POST codes, so you can check your PC's progress as it starts and hopefully identify errors when the POST stops. Use in conjunction with BIOS manufacturers POST codes.

USB CARDS

DIFFERENT KINDS OF USB CARDS AVAILABLE ARE GIVEN BELOW:

USB Card - 2 Port USB 2.0, Low Profile, PCI (32 Bit)

USB Card- 3 Port USB 2.0, PCI (32 Bit) 3 Port USB 2.0 Card 

USB Card - 4+1 Port USB 2.0, PCI (32 Bit)

9 Port, FireWire (IEEE1394a), USB 2.0, Serial-ATA Combo PCI

Versatile expansion card for high-speed drives and peripherals

3 FireWire ports 4 USB 2.0 ports 2 Serial-ATA ports Supports RAID levels 0 and 1 (Mirror and

Stripe set)

USB Card - 3 Port USB 2.0, CardBus (32 Bit)

Add 3 USB 2.0 ports to your portable computer!

Custom I/O Cards

Many other types of input and output circuits are available on custom expansion

cards. An advantage of these is that you’re not limited by an existing interface

design. The card may contain just about any combination of analog and digital

inputs and outputs. In addition, the card may hold timing or clock circuits, function

generators, relay drivers, filters, or just about any type of component related

to the external circuits. With the standard parallel port, you can add these components

externally, but a custom I/O card allows you to place them inside the computer.

To use an expansion card, you of course need an empty expansion slot, which

isn’t available in portable computers and some desktop systems. And the custom

hardware requires custom software.

PC Cards

Finally, instead of using the expansion bus, some I/O cards plug into a PC Card

slot, which accepts slim circuit cards about the size of a playing card. An earlier

name for these was PCMCIA cards, which stands for Personal Computer Memory

Card International Association, whose members developed the standard. Many

portable computers and some desktop models have PC-Card slots. Popular uses

include modems and data acquisition circuits. There are even PC Cards that function

as parallel ports. You don’t need an internal expansion slot, and you don’t

have to open up the computer to plug the card in. But again, the standard parallel-

port interface is cheaper and more widely available