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A framebuffer (frame buffer, or sometimes framestore) is a portion of
random-access memory Random-access memory (RAM; ) is a form of computer memory In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic proces ...
(RAM) containing a
bitmap In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both computer hardware , hardware and softw ...

bitmap
that drives a video display. It is a memory buffer containing data representing all the
pixel In digital imaging Digital imaging or digital image acquisition is the creation of a representation of the visual characteristics of an object, such as a physical scene or the interior structure of an object. The term is often assumed to imp ...

pixel
s in a complete
video frame In filmmaking Filmmaking (or, in any context, film production) is the process by which a film A film, also called a movie, motion picture or moving picture, is a work of visual art used to simulate experiences that communicate ideas, s ...
. Modern
video card A graphics card (also called a video card, display card, graphics adapter, video adapter, or display adapter) is an expansion card which generates a feed of output images to a display device (such as a computer monitor). Frequently, these are ad ...

video card
s contain framebuffer circuitry in their cores. This circuitry converts an in-memory bitmap into a
video signal Video is an electronic Electronic may refer to: *Electronics Electronics comprises the physics, engineering, technology and applications that deal with the emission, flow and control of electrons in vacuum and matter. It uses active de ...
that can be displayed on a computer monitor. In
computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both computer hardware , hardware and software. It has sci ...

computing
, a screen buffer is a part of
computer memory In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both computer hardware , hardware and soft ...
used by a computer application for the representation of the content to be shown on the
computer display A computer monitor is an output device that displays information in pictorial or text form. A monitor usually comprises a electronic visual display, visual display, electronic circuit, some circuitry, a casing, and a power supply. The display dev ...
. The screen buffer may also be called the video buffer, the regeneration buffer, or regen buffer for short. Screen buffers should be distinguished from
video memory Dynamic random-access memory (dynamic RAM or DRAM) is a type of random-access Random access (more precisely and more generally called direct access) is the ability to access an arbitrary element of a sequence in equal time or any datum fr ...
. To this end, the term off-screen buffer is also used. The information in the buffer typically consists of color values for every
pixel In digital imaging Digital imaging or digital image acquisition is the creation of a representation of the visual characteristics of an object, such as a physical scene or the interior structure of an object. The term is often assumed to imp ...

pixel
to be shown on the display. Color values are commonly stored in 1-bit
binary Binary may refer to: Science and technology Mathematics * Binary number In mathematics and digital electronics, a binary number is a number expressed in the base-2 numeral system or binary numeral system, which uses only two symbols: ty ...
(monochrome), 4-bit palettized, 8-bit palettized, 16-bit
high color High color graphics is a method of storing image information in a computer's memory such that each pixel is represented by two bytes. Usually the color is represented by all 16 bits, but some devices also support 15-bit high color. More recently, ...
and 24-bit true color formats. An additional
alpha channel image's alpha channel falls off to zero at its base, where it is blended with the background colour. In computer graphics Computer graphics deals with generating images with the aid of computers. Today, computer graphics is a core technolog ...

alpha channel
is sometimes used to retain information about pixel transparency. The total amount of memory required for the framebuffer depends on the
resolution Resolution(s) may refer to: Common meanings * Resolution (debate), the statement which is debated in policy debate * Resolution (law), a written motion adopted by a deliberative body * New Year's resolution, a commitment that an individual make ...
of the output signal, and on the
color depth Color depth or colour depth (see spelling differences Despite the various English dialects spoken from country to country and within different regions of the same country, there are only slight regional variations in English orthography ...
or
palette Palette may refer to: * Cosmetic palette, an archaeological form * Palette, another name for a color scheme * Palette (painting), a wooden board used for mixing colors for a painting * Palette (company), a Japanese visual novel studio (video game c ...
size.


History

Computer researchers had long discussed the theoretical advantages of a framebuffer, but were unable to produce a machine with sufficient
memory Memory is the faculty of the by which or is , stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If s could not be remembered, it would be impossible for language, r ...
at an economically practicable cost. In 1947, the
Manchester Baby The Manchester Baby, also called the Small-Scale Experimental Machine (SSEM), was the first electronic stored-program computer A stored-program computer is a computer A computer is a machine that can be programmed to carry out sequences ...
computer used a
Williams tube The Williams tube, or the Williams–Kilburn tube after inventors Freddie Williams and Tom Kilburn, is an early form of computer memory In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing ...
, later the Williams-Kilburn tube, to store 1024 bits on a cathode-ray tube (CRT) memory and displayed on a second CRT. Other research labs were exploring these techniques with
MIT Lincoln Laboratory The MIT Lincoln Laboratory, located in Lexington, Massachusetts Lexington is a suburban town in Middlesex County, Massachusetts, United States. It is 11 miles (17 km) from Downtown Boston. The population was 31,394 at the 2010 census, whic ...
achieving a 4096 display in 1950. A color scanned display was implemented in the late 1960s, called the
Brookhaven Brookhaven may refer to: Places in the United States: *Brookhaven, Georgia Brookhaven is a city in the northeastern suburbs of Atlanta that is located in western DeKalb County, Georgia, DeKalb County, Georgia (U.S. state), Georgia, United States, ...
RAster Display (BRAD), which used a
drum memory Drum memory was a magnetic data storage device On a reel-to-reel tape recorder (Sony TC-630), the recorder is data storage equipment and the magnetic tape is a data storage medium. Data Data (; ) are individual facts, statistics, ...
and a television monitor. In 1969, A. Michael Noll of
Bell Labs Nokia Bell Labs (formerly named Bell Labs Innovations (1996–2007), AT&T Bell Laboratories (1984–1996) and Bell Telephone Laboratories (1925–1984)) is an American industrial research and scientific development company A company, abbrev ...
implemented a scanned display with a frame buffer, using
magnetic-core memory Magnetic-core memory was the predominant form of random-access Random access (more precisely and more generally called direct access) is the ability to access an arbitrary element of a sequence in equal time or any datum from a population of ...
. Later on, the Bell Labs system was expanded to display an image with a color depth of three bits on a standard color TV monitor. In the early 1970s, the development of
MOS memory Semiconductor memory is a digital electronic semiconductor device A device is an that relies on the properties of a material (primarily , , and , as well as s) for its function. Semiconductor devices have replaced s in most application ...
( metal-oxide-semiconductor memory) chips, particularly high-density
DRAM Dynamic random-access memory (dynamic RAM or DRAM) is a type of random-access Random access (more precisely and more generally called direct access) is the ability to access an arbitrary element of a sequence in equal time or any datum fr ...

DRAM
(dynamic
random-access memory Random-access memory (RAM; ) is a form of computer memory In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic proces ...
) chips with at least 1 kb memory, made it practical to create, for the first time, a
digital memory Semiconductor memory is a digital electronic semiconductor device A semiconductor A semiconductor material has an Electrical resistivity and conductivity, electrical conductivity value falling between that of a Electrical conductor, conduc ...
system with framebuffers capable of holding a standard video image. This led to the development of the
SuperPaint SuperPaint was a pioneering graphics program and framebuffer computer system developed by Richard Shoup at Xerox PARC PARC (Palo Alto Research Center; formerly Xerox PARC) is a research and development company in Palo Alto, California. Formed i ...

SuperPaint
system by Richard Shoup at
Xerox PARC PARC (Palo Alto Research Center; formerly Xerox PARC) is a research and development company in Palo Alto, California. Founded in 1969 by Jack Goldman, Jacob E. "Jack" Goldman, Xerox Corporation's chief scientist, the company was originally a divis ...
in 1972. Shoup was able to use the SuperPaint framebuffer to create an early digital video-capture system. By synchronizing the output signal to the input signal, Shoup was able to overwrite each pixel of data as it shifted in. Shoup also experimented with modifying the output signal using color tables. These color tables allowed the SuperPaint system to produce a wide variety of colors outside the range of the limited 8-bit data it contained. This scheme would later become commonplace in computer framebuffers. In 1974,
Evans & Sutherland Evans & Sutherland is a pioneering American computer firm in the computer graphics field. Its current products are used in digital projection environments like planetariums. Its simulation business, which it sold to Rockwell Collins, sold products ...
released the first commercial framebuffer, the Picture System, costing about $15,000. It was capable of producing resolutions of up to 512 by 512 pixels in 8-bit
grayscale In digital photography Digital photography uses cameras A camera is an optical Optics is the branch of physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ' ...

grayscale
, and became a boon for graphics researchers who did not have the resources to build their own framebuffer. The
New York Institute of Technology New York Institute of Technology (NYIT), commonly known as New York Tech and by the initials NYIT, is a private research university A research university is a university A university ( la, universitas, 'a whole') is an educational instituti ...
would later create the first 24-bit color system using three of the Evans & Sutherland framebuffers. Each framebuffer was connected to an
RGB s The RGB color model is an additive color, additive color model A color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers, typically as three or four values or color components. When ...

RGB
color output (one for red, one for green and one for blue), with a Digital Equipment Corporation PDP 11/04
minicomputer A minicomputer, or colloquially mini, is a class of smaller general purpose computers that developed in the mid-1960s and sold for much less than Mainframe computer, mainframe and mid-size computers from IBM and BUNCH, its direct competitors. In ...
controlling the three devices as one. In 1975, the UK company
Quantel Quantel was a company based in the United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain,Usage is mixed. The Guardian' and Telegraph' use Britain as a synonym for the ...
produced the first commercial full-color broadcast framebuffer, the Quantel DFS 3000. It was first used in TV coverage of the
1976 Montreal Olympics The 1976 Summer Olympics (french: Jeux olympiques d'été de 1976), officially known as the Games of the XXI Olympiad (French: ''Jeux de la XXIe Olympiade'') and commonly known as Montréal 1976, were an international multi-sport event A mult ...
to generate a
picture-in-picture Picture-in-picture (PiP) is a feature of some television receivers and similar devices. One Television program, program (channel) is displayed on the full TV screen at the same time as one or more other programs are displayed in inset windows. Soun ...
inset of the Olympic flaming torch while the rest of the picture featured the runner entering the stadium. The rapid improvement of integrated-circuit technology made it possible for many of the home computers of the late 1970s to contain low-color-depth framebuffers. Today, nearly all computers with graphical capabilities utilize a framebuffer for generating the video signal.
Amiga The Amiga is a family of personal computers introduced by Commodore International, Commodore in 1985. The original model is one of a number of computers with 16 or 32-bit processors, 256 KB or more of RAM, mouse-based GUIs, and significantly im ...

Amiga
computers, created in the 1980s, featured special design attention to graphics performance and included a unique
Hold-And-Modify Hold-And-Modify, usually abbreviated as HAM, is a display mode of the Commodore International, Commodore Amiga computer. It uses a highly unusual technique to express the color of pixels, allowing many more colors to appear on screen than would ...
framebuffer capable of displaying 4096 colors. Framebuffers also became popular in high-end workstations and
arcade system board An arcade game or coin-op game is a coin-operated entertainment machine typically installed in public businesses such as restaurants, bars and amusement arcades. Most arcade games are presented as primarily games of skill and include arcade ...
s throughout the 1980s.
SGI SGI may refer to: Companies *Saskatchewan Government Insurance Saskatchewan Government Insurance (SGI) is a Canada, Canadian insurance company and a Crown corporations, Crown corporation wholly owned by the Government of Saskatchewan. SGI's opera ...
,
Sun Microsystems Sun Microsystems, Inc. (Sun for short) was an American technology company that sold computer A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations automatically. M ...
, , DEC and
IBM International Business Machines Corporation (IBM) is an American multinational technology company headquartered in Armonk, New York, with operations in over 170 countries. The company began in 1911, founded in Endicott, New York, as the C ...

IBM
all released framebuffers for their workstation computers in this period. These framebuffers were usually of a much higher quality than could be found in most home computers, and were regularly used in television, printing, computer modeling and 3D graphics. Framebuffers were also used by
Sega is a Japanese multinational Multinational may refer to: * Multinational corporation, a corporate organization operating in multiple countries * Multinational force, a military body from multiple countries * Multinational state, a sovereign ...

Sega
for its high-end arcade boards, which were also of a higher quality than on home computers.


Display modes

Framebuffers used in personal and home computing often had sets of defined ''modes'' under which the framebuffer can operate. These modes reconfigure the hardware to output different resolutions, color depths, memory layouts and
refresh rate The refresh rate (or "vertical refresh rate", "vertical scan rate", terminology originating with the cathode ray tube A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, the beams of which are manipulated to dis ...
timings. In the world of
Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser Multi-user software is computer software Software is a collection of Instruction (computer science), instructions that tell a computer how to work. This is in contrast t ...

Unix
machines and operating systems, such conveniences were usually eschewed in favor of directly manipulating the hardware settings. This manipulation was far more flexible in that any resolution, color depth and refresh rate was attainable – limited only by the memory available to the framebuffer. An unfortunate side-effect of this method was that the
display device A display device is an output device An output device is any piece of computer hardware Computer hardware includes the physical parts of a computer A computer is a machine that can be programmed to carry out sequences of arithmetic or ...
could be driven beyond its capabilities. In some cases this resulted in hardware damage to the display. More commonly, it simply produced garbled and unusable output. Modern CRT monitors fix this problem through the introduction of protection circuitry. When the display mode is changed, the monitor attempts to obtain a signal lock on the new refresh frequency. If the monitor is unable to obtain a signal lock, or if the signal is outside the range of its design limitations, the monitor will ignore the framebuffer signal and possibly present the user with an error message. LCD monitors tend to contain similar protection circuitry, but for different reasons. Since the LCD must digitally sample the display signal (thereby emulating an electron beam), any signal that is out of range cannot be physically displayed on the monitor.


Color palette

Framebuffers have traditionally supported a wide variety of color modes. Due to the expense of memory, most early framebuffers used 1-bit (2-colors per pixel), 2-bit (4-colors), 4-bit (16-colors) or 8-bit (256-colors) color depths. The problem with such small color depths is that a full range of colors cannot be produced. The solution to this problem was
indexed color In computing, indexed color is a technique to manage digital image A digital image is an composed of s, also known as ''pixels'', each with ', ' of numeric representation for its or that is an output from its fed as input by its denoted ...
which adds a
lookup table In computer science Computer science deals with the theoretical foundations of information, algorithms and the architectures of its computation as well as practical techniques for their application. Computer science is the study of , , a ...
to the framebuffer. Each color stored in framebuffer memory acts as a color index. The lookup table serves as a palette with a limited number of different colors meanwhile the rest is used as an index table. Here is a typical indexed 256-color image and its own palette (shown as a rectangle of swatches): : In some designs it was also possible to write data to the LUT (or switch between existing palettes) on the run, allowing dividing the picture into horizontal bars with their own palette and thus render an image that had a far wider palette. For example, viewing an outdoor shot photograph, the picture could be divided into four bars, the top one with emphasis on sky tones, the next with foliage tones, the next with skin and clothing tones, and the bottom one with ground colors. This required each palette to have overlapping colors, but carefully done, allowed great flexibility.


Memory access

While framebuffers are commonly accessed via a memory mapping directly to the CPU memory space, this is not the only method by which they may be accessed. Framebuffers have varied widely in the methods used to access memory. Some of the most common are: * Mapping the entire framebuffer to a given memory range. * Port commands to set each pixel, range of pixels or palette entry. * Mapping a memory range smaller than the framebuffer memory, then
bank switching Bank switching is a technique used in computer design to increase the amount of usable memory beyond the amount directly addressable by the processor instructions. It can be used to configure a system differently at different times; for example ...
as necessary. The framebuffer organization may be
packed pixel In packed pixel or chunky framebuffer A framebuffer (frame buffer, or sometimes framestore) is a portion of (RAM) containing a that drives a video display. It is a containing data representing all the s in a complete . Modern s contain framebu ...
or
planar Planar may refer to: Science and technology * Planar (computer graphics) In computer graphics, planar is the method of arranging pixel data into several '' bitplanes'' of RAM. Each bit in a bitplane is related to one pixel on the screen. Unlike ...
. The framebuffer may be
all points addressable "Bling Bling": Dot matrix-style skywriting. A dot matrix is a 2-dimensional patterned array ARRAY, also known as ARRAY Now, is an independent distribution company launched by film maker and former publicist Ava DuVernay in 2010 under the nam ...
or have restrictions on how it can be updated.


RAM on the video card

Video cards always have a certain amount of RAM. This RAM is where the bitmap of image data is "buffered" for display. The term ''frame buffer'' is thus often used interchangeably when referring to this RAM. The CPU sends image updates to the video card. The video processor on the card forms a picture of the screen image and stores it in the frame buffer as a large bitmap in RAM. The bitmap in RAM is used by the card to continually refresh the screen image.


Virtual framebuffers

Many systems attempt to emulate the function of a framebuffer device, often for reasons of compatibility. The two most common virtual framebuffers are the
Linux framebuffer Image:KNOPPIX booting.png, Knoppix booting on the framebuffer The Linux framebuffer (fbdev) is a graphic hardware-independent abstraction layer to show computer graphics, graphics on a computer monitor, typically on the system console. It allows d ...
device (fbdev) and the X Virtual Framebuffer (
Xvfb Xvfb or X virtual framebuffer is a display server In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithm of an algorithm ...
). Xvfb was added to the
X Window System The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like A Unix-like (sometimes referred to as UN*X or *nix) operating system An operating system (OS) is system software that manages computer ...
distribution to provide a method for running X without a graphical framebuffer. The Linux framebuffer device was developed to abstract the physical method for accessing the underlying framebuffer into a guaranteed memory map that is easy for programs to access. This increases portability, as programs are not required to deal with systems that have disjointed memory maps or require
bank switching Bank switching is a technique used in computer design to increase the amount of usable memory beyond the amount directly addressable by the processor instructions. It can be used to configure a system differently at different times; for example ...
.


Page flipping

A frame buffer may be designed with enough memory to store two frames worth of video data. In a technique known generally as
double buffering In computer science, multiple buffering is the use of more than one buffer (computer science), buffer to hold a block of data, so that a "reader" will see a complete (though perhaps old) version of the data, rather than a partially updated versi ...
or more specifically as
page flipping In computer science, multiple buffering is the use of more than one buffer (computer science), buffer to hold a block of data, so that a "reader" will see a complete (though perhaps old) version of the data, rather than a partially updated versi ...
, the framebuffer uses half of its memory to display the current frame. While that memory is being displayed, the other half of memory is filled with data for the next frame. Once the secondary buffer is filled, the framebuffer is instructed to display the secondary buffer instead. The primary buffer becomes the secondary buffer, and the secondary buffer becomes the primary. This switch is often done after the
vertical blanking interval In a raster scan A raster scan, or raster scanning, is the rectangular pattern of image capture and reconstruction in television. By analogy, the term is used for raster graphics upright=1, The Smiley, smiley face in the top left corner i ...
to avoid
screen tearing Screen tearing is a visual artifact in video display where a display device s, LED display and Vacuum fluorescent display, VF display, top to bottom. A display device is an output device for presentation of information in visual or Touch, tact ...
where half the old frame and half the new frame is shown together. Page flipping has become a standard technique used by PC
game programmer A game programmer is a software engineer, programmer, or computer scientist who primarily develops codebases for video games or related software, such as game development tools. Game programming has many specialized disciplines, all of which fall ...
s.


Graphics accelerators

As the demand for better graphics increased, hardware manufacturers created a way to decrease the amount of
CPU A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuit File:PExdcr01CJC.jpg, 200px, A circuit built on a printed circuit board (PCB). An electronic circuit is composed of ...

CPU
time required to fill the framebuffer. This is commonly called ''graphics acceleration''. Common graphics drawing commands (many of them geometric) are sent to the graphics accelerator in their raw form. The accelerator then rasterizes the results of the command to the framebuffer. This method frees the CPU to do other work. Early accelerators focused on improving the performance of 2D
GUI#REDIRECT graphical user interface The graphical user interface (GUI "UI" by itself is still usually pronounced . or ) is a form of user interface that allows User (computing), users to Human–computer interaction, interact with electronic devic ...
systems. While retaining these 2D capabilities, most modern accelerators focus on producing 3D imagery in real time. A common design uses a
graphics library A graphics library is a program library A library is a collection of materials, books or media that are easily accessible for use and not just for display purposes. It is responsible for housing updated information in order to meet the user' ...
such as
OpenGL OpenGL (Open Graphics Library) is a cross-language, cross-platform In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithm ...
or
Direct3D Direct3D is a graphics application programming interface (API) for Microsoft Windows. Part of DirectX, Direct3D is used to render 3D computer graphics, three-dimensional graphics in applications where performance is important, such as games. Dir ...
which interfaces with the graphics driver to translate received commands to instructions for the accelerator's
graphics processing unit A graphics processing unit (GPU) is a specialized electronic circuit 200px, A circuit built on a printed circuit board (PCB). An electronic circuit is composed of individual electronic component An electronic component is any basic discre ...
(GPU). The GPU uses those instructions to compute the rasterized results and the results are
bit blit Bit blit (also written BITBLT, BIT BLT, BitBLT, Bit BLT, Bit Blt etc., which stands for ''bit block transfer'') is a data operation commonly used in computer graphics in which several bitmaps are combined into one using a '' boolean function. The ...
ted to the framebuffer. The framebuffer's signal is then produced in combination with built-in video overlay devices (usually used to produce the mouse cursor without modifying the framebuffer's data) and any final special effects that are produced by modifying the output signal. An example of such final special effects was the
spatial anti-aliasing In digital signal processing, spatial anti-aliasing is a technique for minimizing the distortion artifacts (aliasing) when representing a high-resolution image at a lower resolution. Anti-aliasing is used in digital photography, computer graphics ...
technique used by the 3dfx Voodoo cards. These cards add a slight blur to output signal that makes aliasing of the rasterized graphics much less obvious. At one time there were many manufacturers of graphics accelerators, including:
3dfx Interactive 3dfx Interactive was a company headquartered in San Jose, California San Jose, officially San José (; ; ), is the largest city in Northern California Northern California (colloquially known as NorCal) is a geographic and cultural region t ...
; ATI;
Hercules Hercules (, ) is the Roman equivalent of the Greek divine Divinity or the divine are things that are either related to, devoted to, or proceeding from a deity A deity or god is a supernatural The supernatural encompasses supposed p ...
;
Trident A trident is a three-tine (structural), pronged spear. It is used for spear fishing and historically as a polearm. The trident is the weapon of Poseidon, or Neptune (mythology), Neptune, the God of the Sea in classical mythology. The trident ma ...
;
Nvidia Nvidia CorporationOfficially written as NVIDIA and stylized in its logo as nVIDIA with the lowercase "n" the same height as the uppercase "VIDIA"; formerly stylized as ''n''VIDIA with a large italicized lowercase "n" on products from the mid 19 ...
;
Radius In classical geometry Geometry (from the grc, γεωμετρία; ' "earth", ' "measurement") is, with , one of the oldest branches of . It is concerned with properties of space that are related with distance, shape, size, and relative ...
;
S3 Graphics S3 Graphics, Ltd (commonly referred to as S3) was an American computer graphics company. The company sold the S3 Trio, Trio, S3 ViRGE, ViRGE, S3 Savage, Savage 3D, and S3 Chrome, Chrome series of graphics processors. Struggling against competition ...
; SiS and
Silicon Graphics Silicon Graphics, Inc. (stylized as ''SiliconGraphics'' before 1999, later rebranded SGI, historically known as Silicon Graphics Computer Systems or SGCS) was an American high-performance computing A supercomputer is a computer with a hig ...
. the market for graphics accelerators for x86-based systems is dominated by Nvidia (acquired 3dfx in 2002),
AMD Advanced Micro Devices, Inc. (AMD) is an American multinational Multinational may refer to: * Multinational corporation, a corporate organization operating in multiple countries * Multinational force, a military body from multiple countries * M ...

AMD
(who acquired ATI in 2006), and
Intel Intel Corporation is an American multinational corporation A multinational company (MNC) is a corporate A corporation is an organization—usually a group of people or a company A company, abbreviated as co., is a Legal personalit ...

Intel
(which currently produces only integrated GPUs rather than discrete video cards).


Comparisons

With a framebuffer, the electron beam (if the display technology uses one) is commanded to perform a
raster scan A raster scan, or raster scanning, is the rectangular pattern of image capture and reconstruction in television. By analogy, the term is used for raster graphics upright=1, The Smiley, smiley face in the top left corner is a raster image. Wh ...
, the way a
television Television, sometimes shortened to TV or telly, is a telecommunication Telecommunication is the transmission of information by various types of technologies over wire A wire is a single usually cylindrical A cylinder (from Gre ...

television
renders a broadcast signal. The color information for each point thus displayed on the screen is pulled directly from the framebuffer during the scan, creating a set of discrete picture elements, i.e. pixels. Framebuffers differ significantly from the
vector display A vector monitor, vector display, or calligraphic display is a display device s, LED display and Vacuum fluorescent display, VF display, top to bottom. A display device is an output device for presentation of information in visual or Touch, tac ...
s that were common prior to the advent of raster graphics (and, consequently, to the concept of a framebuffer). With a vector display, only the vertices of the graphics primitives are stored. The
electron beam Cathode rays (electron beam or e-beam) are streams of electron The electron is a subatomic particle In physical sciences, subatomic particles are smaller than atom An atom is the smallest unit of ordinary matter In classical ...
of the output display is then commanded to move from vertex to vertex, tracing a line across the area between these points. Likewise, framebuffers differ from the technology used in early
text mode Text mode is a computer display A computer monitor is an output device that displays information in pictorial or text form. A monitor usually comprises a electronic visual display, visual display, electronic circuit, some circuitry, a casing, ...
displays, where a buffer holds codes for characters, not individual pixels. The video display device performs the same raster scan as with a framebuffer, but generates the pixels of each character in the buffer as it directs the beam.


See also

*
Bit plane A bit plane of a digital discrete signalIn Dynamical system, mathematical dynamics, discrete time and continuous time are two alternative frameworks within which to model Variable (mathematics), variables that evolve over time. Discrete time Ima ...
*
Scanline rendering Scanline rendering (also scan line rendering and scan-line rendering) is an algorithm for visible surface determination, in 3D computer graphics 3D computer graphics, sometimes called CGI, 3DCG or three-dimensional computer graphics Co ...
* Swap chain *
Tile-based video game A tile-based video game is a type of video or video game where the playing area consists of small square (or, much less often, rectangular, parallelogram, or hexagonal) graphic images referred to as ''tiles'' laid out in a grid. That the screen i ...
*
Tiled rendering Tiled rendering is the process of subdividing a computer graphics Computer graphics deals with generating images with the aid of computers. Today, computer graphics is a core technology in digital photography, film, video games, cell phone a ...


References

* * *


External links


Interview with NYIT researcher discussing the 24-bit system


{{Graphics Processing Unit Computer graphics Computer memory
Image processing Digital image processing is the application of signal processing techniques to the domain of images — two-dimensional Wiktionary:signal, signals such as photography, photographs or video. Image processing does typically involve filtering or en ...
User interfaces