Download Before the invention of the sound card, a PC could make one sound

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-graphicsdisplays 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 highperformance 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 fastaction 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 depth
Each 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
Description
4-bit
No.
of
Bytes
colours
pixel
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
per
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.
Resolution
Resolution 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
1Mb
Colour
Resolution
1024
x
depth
768
800 x 600
No. colours
8-bit
256
16-bit
65,536
1024
x
768
8-bit
256
1280
x
1024
16-bit
65,536
800 x 600
24-bit
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
2Mb
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
Analog line level input.
Blue
Lime
Analog line level output for the main
green
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 fullduplex.
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
Architecture). Both include drivers for most
(Advanced
Linux
Sound
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 recording
When 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
13
PRODUCT
Netw ork_Interfac
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
13
PRODUCT
Netw ork_Interfac
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!
13
PRODUCT
Netw ork_Interfac
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.
13
PRODUCT
Netw ork_Interfac
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 gold-plated to limit oxidization and extend the life of
the card.
13
PRODUCT
Netw ork_Interfac
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.
13
PRODUCT
Wireless
LAN
Connect
Connect
your
your
PCI
Card
desktop
desktop
Netw ork_Interfac
-
802.11g,
PC
PC
to
to
54Mbps Ref: UNI52011
your
your
Wireless
Wireless
LAN!
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
13
PRODUCT
Netw ork_Interfac
PCMCIA (16 Bit) Fast Ethernet 10/100 Adapter Ref: UNI70983-1
Attach
Attach
your
your
laptop
laptop
or
or
notebook
notebook
to
to
a
a
10/100Mbps
10/100Mbps
network!
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
IRQ
Card
Software
Address:
“Plug
&
Selection:
“Plug
&
Connector:
RJ-45
STP/UTP
Compatibility:
Windows
98SE/ME/NT/2000/XP
and
13
PRODUCT
Netw ork_Interfac
Play”
Play”
(10/100Base-TX)
NDIS
3.0,
4.0
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
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 zbuffer 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 "leasedline" 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 parallelport interface is cheaper and more widely available