This is a list of notable
8-bit
In computer architecture, 8-bit integers or other data units are those that are 8 bits wide (1 octet). Also, 8-bit central processing unit (CPU) and arithmetic logic unit (ALU) architectures are those that are based on registers or data buses of ...
computer
color palettes, and graphics, which were primarily manufactured from 1975 to 1985. Although some of them use
RGB palettes, more commonly they have 4, 16 or more color palettes that are not bit nor level combinations of
RGB
The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additiv ...
primaries, but fixed ROM/circuitry colors selected by the manufacturer. Due to mixed-bit architectures, the ''n''-bit distinction is not always a strict categorization. Another common mistake is the assumption that a color palette of a given computer is what it can display all at once. Resolution is also a crucial aspect when criticizing an 8-bit computer, as many offer different modes with different amounts of colors on screen, and different resolutions, with the intent of trading off resolution for color, and vice versa.
:
3-bit RGB palettes
Systems with a 3-bit RGB palette use 1 bit for each of the red, green and blue color components. That is, each component is either "on" or "off" with no intermediate states. This results in an 8-color palette ((2
1)
3 2
3 8) that have black, white, the three RGB primary colors red, green and blue and their correspondent complementary colors cyan, magenta and yellow as follows:
:
The color indices vary between implementations; therefore, index numbers are not given. A common selection has 3 bits (from LSB to MSB) directly representing the 'Red', 'Green' and 'Blue' (RGB) components in a number from 0 to 7. An alternate arrangement uses the bit order 'Blue', 'Red', 'Green' (BRG), such that the resultant palette - in numerical order - represents an increasing level of intensity on a monochrome display.
The 3-bit RGB palette is used by:
*The ECMA-48 standard for
text terminal
A computer terminal is an electronic or electromechanical hardware device that can be used for entering data into, and transcribing data from, a computer or a computing system. The teletype was an example of an early-day hard-copy terminal an ...
s (sometimes known as the "ANSI standard", although
ANSI X3.64
ANSI escape sequences are a standard for in-band signaling to control cursor location, color, font styling, and other options on video text terminals and terminal emulators. Certain sequences of bytes, most starting with an ASCII escape cha ...
does not define colors)
*
Teletext
A British Ceefax football index page from October 2009, showing the three-digit page numbers for a variety of football news stories
Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipp ...
Level 1/1.5 Teletext.
*
Videotex
Videotex (or interactive videotex) was one of the earliest implementations of an end-user information system. From the late 1970s to early 2010s, it was used to deliver information (usually pages of text) to a user in computer-like format, typi ...
*
Oric
Oric was the name used by UK-based Tangerine Computer Systems for a series of 6502-based home computers sold in the 1980s, primarily in Europe.
With the success of the ZX Spectrum from Sinclair Research, Tangerine's backers suggested a ...
*
BBC Micro
The British Broadcasting Corporation Microcomputer System, or BBC Micro, is a series of microcomputers and associated peripherals designed and built by Acorn Computers in the 1980s for the BBC Computer Literacy Project. Designed with an empha ...
*The original NEC
PC-8801
The , commonly shortened to PC-88, are a brand of Zilog Z80-based 8-bit home computers released by Nippon Electric Company (NEC) in 1981 and primarily sold in Japan.
The PC-8800 series sold extremely well and became one of the three major Japa ...
up to the MkII
*The original NEC
PC-9801
The , commonly shortened to PC-98 or , is a lineup of Japanese 16-bit and 32-bit personal computers manufactured by NEC from 1982 to 2000. The platform established NEC's dominance in the Japanese personal computer market, and, by 1999, more ...
with original 8086 CPU before the VM/VX models
*All
Sharp X1
The , sometimes called the Sharp X1 or CZ-800C, is a series of home computers released by Sharp Corporation from 1982 to 1988. It is based on a Zilog Z80 CPU.
The RGB display monitor for the X1 had a television tuner, and a computer screen ...
models before the X1 Turbo Z
*The
Sharp MZ
The Sharp MZ is a series of personal computers sold in Japan and Europe (particularly Germany and Great Britain) by Sharp beginning in 1978.
History
Although commonly believed to stand for "Microcomputer Z80", the term MZ actually has i ...
700
*Fujitsu
FM-7
The FM-7 ("Fujitsu Micro 7") is a home computer created by Fujitsu. It was first released in 1982 and was sold in Japan and Spain. It is a stripped-down version of Fujitsu's earlier FM-8 computer, and during development it was referred to as the ...
, FM New 7, FM 77 before the FM77AV
*
Sinclair QL
The Sinclair QL (for ''Quantum Leap'') is a personal computer launched by Sinclair Research in 1984, as an upper-end counterpart to the ZX Spectrum. The QL was aimed at the serious home user and professional and executive users markets from small ...
*The
Macintosh SE
The Macintosh SE is a personal computer designed, manufactured, and sold by Apple Computer, from March 1987 to October 1990. It marked a significant improvement on the Macintosh Plus design and was introduced by Apple at the same time as the Mac ...
with a color printer or external monitor
*The
SECAM
SECAM, also written SÉCAM (, ''Séquentiel de couleur à mémoire'', French for ''color sequential with memory''), is an analog color television system that was used in France, some parts of Europe and Africa, and Russia. It was one of th ...
version of the
Atari 2600
The Atari 2600, initially branded as the Atari Video Computer System (Atari VCS) from its release until November 1982, is a home video game console developed and produced by Atari, Inc. Released in September 1977, it popularized microprocess ...
*The Color
Maximite Maximite Microcomputer is a Microchip PIC32 microcontroller-based microcomputer. Originally designed as a hobby kit, the Maximite was introduced in a three-part article in Silicon Chip magazine in autumn of 2011 by Australian designer Geoff Graham ...
, a PIC32 based microcomputer
*The
Thomson TO7 Thomson may refer to:
Names
* Thomson (surname), a list of people with this name and a description of its origin
* Thomson baronets, four baronetcies created for persons with the surname Thomson
Businesses and organizations
* SGS-Thomson Mi ...
(with spatial constraints - only 2 colours for each group of 8x1 pixels)
*The
Matra Alice
The Matra & Hachette Ordinateur Alice is a home computer sold in France beginning in 1983. It was a clone of the TRS-80 MC-10, produced through a collaboration between Matra and Hachette in France and Tandy Corporation in the United States.
T ...
32 and 90
*The
Philips VG5000
The VG5000μ is a computer created by Philips in 1984. It was manufactured in Le Mans by Radiotechnique (RTS) and marketed under the Philips, Radiola and Schneider brands.
Not compatible with any other machines, it offered VG5000 BASIC (deri ...
Specific details about implementation and actual graphical capabilities of specific systems, are listed on the next sub-sections.
World System Teletext Level 1
World System Teletext Level 1 (1976) uses a
3-bit RGB, 8-color palette. Teletext has 40×25 characters per page of which the first row is reserved for a page header. Every character cell has a background color and a text color. These attributes along with others are set through control codes which each occupy one character position.
Graphics characters consisting of 2×3 cells can used following a graphics color attribute. Up to a maximum of 72×69 blocky pixels can be used on a page.
Simulated image
:
BBC Micro
BBC Micro
The British Broadcasting Corporation Microcomputer System, or BBC Micro, is a series of microcomputers and associated peripherals designed and built by Acorn Computers in the 1980s for the BBC Computer Literacy Project. Designed with an empha ...
has 8 display modes, with resolutions like 640×256 (max. 2 colors), 320×256 (max. 4 colors) and 160×256 (max. 16 logical colors). No display modes have cell attribute clashes. The palette available has only 8 physical colors, plus a further 8 flashing colors (each being one of the eight non-flashing colors alternating with its physical complement every second), and the display modes can have 16, 4 or 2 simultaneous colors.
Simulated image
:
BBC Micro display modes
:
:
Sinclair QL (Sinclair Quantum Leap)
On the Sinclair QL two video modes were available, 256×256 pixels with 8
RGB
The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additiv ...
colors and per-pixel flashing, or 512×256 pixels with four colors: black, red, green and white. The supported colors could be stippled in 2×2 blocks to simulate up to 256 colors, an effect which did not copy reliably on a TV, especially over an RF connection.
Pixel aspect ratio was not square, with resulting image proportions close to 4.4:3, making the image extend into the horizontal
overscan
Overscan is a behaviour in certain television sets, in which part of the input picture is shown outside of the visible bounds of the screen. It exists because cathode-ray tube (CRT) television sets from the 1930s through to the early 2000s were h ...
area of a
CRT TV
A television set or television receiver, more commonly called the television, TV, TV set, telly, tele, or tube, is a device that combines a tuner, display, and loudspeakers, for the purpose of viewing and hearing television broadcasts, or using ...
.
:
:
PC-8000 series
The NEC
PC-8000
The is a line of personal computers developed for the Japanese market by NEC. The PC-8001 model was also sold in the United States and Canada as the PC-8001A.
Original models of the NEC PC-8001B (or sometimes the NEC PC-8000) were also sold in so ...
was capable of displaying graphics with a resolution of 160x100 pixels and 8 colors.
4-bit RGBI palettes
:
The 4-bit RGBI palette is similar to the 3-bit RGB palette but adds one bit for ''intensity''. This allows each of the colors of the 3-bit palette to have a variant (on most machines ''dark'' or ''bright'', but ''saturated'' or ''unsaturated'' was also possible) potentially giving a total of 2
3×2 16 colors. Some implementations had only 15 effective colors due to the "dark" and "bright" variations of black being displayed identically. Others generated a grey tone or a different color.
This 4-bit RGBI schema is used in several platforms with variations, so the table given below is a simple reference for the palette richness, and not an actual implemented palette. For this reason, no numbers are assigned to each color, and color order is arbitrary.
:
Systems that used this palette scheme:
* IBM's original
Color Graphics Adapter
The Color Graphics Adapter (CGA), originally also called the ''Color/Graphics Adapter'' or ''IBM Color/Graphics Monitor Adapter'', introduced in 1981, was IBM's first color graphics card for the IBM PC and established a de facto computer disp ...
* IBM's
Enhanced Graphics Adapter
The Enhanced Graphics Adapter (EGA) is an IBM PC graphics adapter and de facto computer display standard from 1984 that superseded the CGA standard introduced with the original IBM PC, and was itself superseded by the VGA standard in 1987. In ...
, in CGA modes
*
Tandy graphics on IBM's
PCjr
The IBM PCjr (pronounced "PC junior") was a home computer produced and marketed by IBM from March 1984 to May 1985, intended as a lower-cost variant of the IBM PC with hardware capabilities better suited for video games, in order to compete mor ...
and
Tandy 1000-series computers
*
Plantronics Colorplus
The Plantronics Colorplus is a graphics card for IBM PC computers, first sold in 1982. It is a superset of the then-current CGA standard, using the same monitor standard and providing the same pixel resolutions. It was produced by Frederick Ele ...
on a limited number of PC-compatible computers
*
MCGA and
VGA
Video Graphics Array (VGA) is a video display controller and accompanying de facto graphics standard, first introduced with the IBM PS/2 line of computers in 1987, which became ubiquitous in the Personal computer, PC industry within three years ...
graphics standards for backward compatibility
*
Commodore 128
The Commodore 128, also known as the C128, C-128, C= 128,The "C=" represents the graphical part of the logo. is the last 8-bit home computer that was commercially released by Commodore Business Machines (CBM). Introduced in January 1985 at the ...
series for its 80-column mode
*
ZX Spectrum (and compatible)
*
CPC 464
The CPC 464 is the first personal home computer built by Amstrad in 1984. It was one of the bestselling and best produced microcomputers, with more than 2 million units sold in Europe. The British microcomputer boom had already peaked before Am ...
/
664
__NOTOC__
Year 664 ( DCLXIV) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar. The denomination 664 for this year has been used since the early medieval period, when the Anno Domini calendar era be ...
/
6128
*
Sharp MZ
The Sharp MZ is a series of personal computers sold in Japan and Europe (particularly Germany and Great Britain) by Sharp beginning in 1978.
History
Although commonly believed to stand for "Microcomputer Z80", the term MZ actually has i ...
-800 series computers
*
Thomson MO5
The Thomson MO5 is a home computer introduced in France in June 1984 to compete against systems such as the ZX Spectrum and Commodore 64. It had a release price of 2390 FF.
At the same time, Thomson also released the up-market Thomson TO7/ ...
and
TO7
Specific details about implementation and actual graphical capabilities of specific systems, are listed on the next sub-sections.
ZX Spectrum
The
ZX Spectrum (and compatible) computers use a variation of the
4-bit RGBI palette philosophy. This results in each of the colors of the 3-bit palette to have a ''basic'' and ''bright'' variant, with the exception of black. This was accomplished by having a maximum voltage level for the bright variant, and a lower voltage level for the basic variant. Due to this, black is the same in both variants.
The ''attribute'' byte associated with every 8×8 pixel cell comprises (from LSB to MSB): three bits for the background color; three bits for the foreground color; one bit for the ''bright'' variant for both, and one bit for the flashing effect (alternate foreground and background colors every 0.32 seconds). Thus the colors are not independently selectable as indices of a true palette (there are not color numbers 8 to 15, and the ''bright'' bit affects both colors within a cell). However, within a single set of 8 colors the BRG order of bits means that the colors appear in increasing order of brightness on a monochrome display.
The color number (0 to 7) can be employed with the following
BASIC
BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Thomas E. Kurtz at Dartmouth College ...
statements to choose:
* BORDER ''n'', the color for the surrounding area outside the pixel graphical area. This cannot use the ''bright'' variants.
* PAPER ''n'', the background (pixel bit value of 0) color for an 8×8 pixel cell.
* INK ''n'', the foreground (pixel bit value of 1) color for an 8×8 pixel cell.
And a value of 0 or 1 with the following statements to choose:
* BRIGHT ''n'', sets the ''bright'' bit for both foreground and background colors in an 8×8 pixel cell.
* FLASH ''n'', sets the bit that controls the flashing effect in an 8×8 pixel cell.
:
:
IBM PC/XT and compatible systems
The original
IBM PC
The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a tea ...
launched in 1981 features an
Intel 8088
The Intel 8088 ("''eighty-eighty-eight''", also called iAPX 88) microprocessor is a variant of the Intel 8086. Introduced on June 1, 1979, the 8088 has an eight-bit external Bus (computing), data bus instead of the 16-bit computing, 16-bit bus of ...
CPU
A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, an ...
which has 8-bit
data bus
In computer architecture, a bus (shortened form of the Latin ''omnibus'', and historically also called data highway or databus) is a communication system that transfers data between components inside a computer, or between computers. This ex ...
technology, though internally the CPU has a fully 16-bit architecture. It was offered with a
Monochrome Display Adapter (MDA) or a
Color Graphics Adapter (CGA). The MDA is a
text mode
Text mode is a computer display mode in which content is internally represented on a computer screen in terms of characters rather than individual pixels. Typically, the screen consists of a uniform rectangular grid of ''character cells'', each o ...
-only display adapter, without any graphic ability beyond using the built-in
code page 437
Code page 437 (CCSID 437) is the character set of the original IBM PC (personal computer). It is also known as CP437, OEM-US, OEM 437, PC-8, or DOS Latin US. The set includes all printable ASCII characters as well as some accented letters (diac ...
character set (which includes half-block and line-drawing characters), and employed an original IBM green
monochrome monitor
A monochrome monitor is a type of computer monitor in which computer text and images are displayed in varying tones of only one color, as opposed to a color monitor that can display text and images in multiple colors. They were very common in t ...
; only black, green and intensified green could be seen on its screen. Then, only the CGA had true graphic modes.
The
IBM PC XT
The IBM Personal Computer XT (model 5160, often shortened to PC/XT) is the second computer in the IBM Personal Computer line, released on March 8, 1983. Except for the addition of a built-in hard drive and extra expansion slots, it is very simila ...
model, which succeeded the original PC in 1983, has an identical architecture and CPU to its predecessor, only with more expansion slots and a hard disk equipped as standard. The same two video cards, the MDA and the CGA, remained available for the PC XT, and no upgraded video hardware was offered by IBM until the EGA, which followed the introduction of the
IBM Personal Computer/AT
The IBM Personal Computer/AT (model 5170, abbreviated as IBM AT or PC/AT) was released in 1984 as the fourth model in the IBM Personal Computer line, following the IBM PC/XT and its IBM Portable PC variant. It was designed around the Intel 802 ...
, with its full 16-bit bus design, in 1984.
CGA
The
Color Graphics Adapter
The Color Graphics Adapter (CGA), originally also called the ''Color/Graphics Adapter'' or ''IBM Color/Graphics Monitor Adapter'', introduced in 1981, was IBM's first color graphics card for the IBM PC and established a de facto computer disp ...
(CGA) outputs what IBM called "digital RGB" (that is, the R, G, B (and I) signals from the graphics card to the monitor can each only have two states: on or off). CGA supports a maximum of 16 colors. However, its 320×200 graphics mode is restricted to fixed palettes containing only four colors, and the 640×200 graphic mode is only two colors. 16 colors are only available in text mode or the "tweaked text" 160×100 mode. A different set of 16 colors is available in composite mode with an NTSC composite monitor. (Independent groups have also demonstrated much larger composite color sets—over 256 colors—on a
composite monitor
A composite monitor or composite video monitor is any analog video display that receives input in the form of an analog composite video signal to a defined specification. A composite video signal encodes all information on a single conductor; a c ...
by the use of
artifact color
Composite artifact colors is a designation commonly used to address several graphic modes of some 1970s and 1980s home computers. With some machines, when connected to an NTSC TV or monitor over composite video outputs, the video signal enc ...
techniques. See
Color Graphics Adapter#High color depth.)
The full standard RGBI palette is a variant of the
4-bit RGBI schema. Although the RGBI signals each have only two states, the CGA color monitor decodes them as if RGB signals had four levels. Darker colors are the basic RGB 2nd level signals except for brown, which is dark yellow with the level for the green component halved (1st level). Brighter colors are made by adding a uniform intensity one-level signal to every RGB signal of the dark ones, reaching the 3rd level (except dark gray which reaches only the 1st level), and in this case yellow is produced as if the brown were ordinary dark yellow.
:
:
The color numbers above are not arbitrary; they are based on the following bitmask:
:
*A few earlier non-IBM compatible CGA monitors lack the circuitry to decode color numbers as of four levels internally, and they cannot show brown and dark gray. The above palette is displayed in such monitors as follows:
:
* 16-color palette modes
The only full 16-color
BIOS
In computing, BIOS (, ; Basic Input/Output System, also known as the System BIOS, ROM BIOS, BIOS ROM or PC BIOS) is firmware used to provide runtime services for operating systems and programs and to perform hardware initialization during the ...
modes of the CGA are the text mode 0 (40×25) and mode 2 (80×25). Disabling the flashing attribute effect and using the IBM
437 codepage block characters 220 (DCh) ▄ (bottom half) or 223 (DFh) ▀ (upper half), the mode 2 screen buffer provides an 80×50 quasi-graphic mode.
Also, a
tweak mode can be set in the
CGA to give an extra, non-standard 160×100 pixels 16-color graphic mode.
:
* 4-color palette modes
In the 320×200 graphics mode, every pixel has two bits. A value of 0 is always a selectable background-plus-border color (with the same register and/or BIOS call used for the foreground color in the 640×200 graphic mode; black by default), and the three remaining values 1 to 3 are indices to one of the predefined color palette entries.
The selection of a palette is a bit complex. There are two BIOS 320×200 CGA graphics modes: modes 4 and 5. Mode 4 has the composite color burst output enabled (in the Mode Control Register at I/O address 3D8H, bit 2 is cleared), and mode 5 has it disabled (the same bit 2 is set). Mode 5 is intended mainly for a monochrome
composite video monitor
A composite monitor or composite video monitor is any analog video display that receives input in the form of an analog composite video signal to a defined specification. A composite video signal encodes all information on a single conductor; a c ...
, but because of a specific intentional feature of the CGA hardware, it also has a different palette for an RGBI color monitor. For mode 4, two palettes can be chosen: green/red/brown and cyan/magenta/white; the difference is the absence or presence of the blue signal in all three colors. (The palette is selected with bit 5 of the Color-Select Register at I/O address 3D9h, where the bit value 1 selects the cyan/magenta/white palette
/k/a "palette #1" because it is the BIOS defaultand 0 selects the green/red/brown palette
/k/a "palette #2" This bit can be set using BIOS INT 10h function 0Bh, subfunction 1.) The palette for BIOS video mode 5 is always cyan/red/white: blue is always on, and red and green each are controlled directly by one of the two bits of the pixel color value. For each of these three palette options, a low or high intensity palette can be chosen with bit 4 of the aforementioned Color-Select Register: a value of 0 means low intensity and 1 means high intensity. (No BIOS call exists to switch between the two intensity modes.) The selected intensity setting simply controls the "I" output signal to the RGBI monitor for all colors in the palette. As a result, the green-red-brown palette appears as bright-green/bright-red/yellow when high intensity is selected. The combination of color-burst enable/disable selection, palette selection, and intensity selection yields a total of 6 different possible palettes for CGA 320×200 graphics.
:*Mode 4, palette #1, low intensity:
::
::The sixteen combinations with the background color are:
::
::
::(*) Useless due to the duplication of one of the colors.
:*Mode 4, palette #1, high intensity:
::
::The sixteen combinations with the background color are:
::
::
::(*) Useless due to the duplication of one of the colors.
:*Mode 4, palette #2, low intensity:
::
::The sixteen combinations with the background color are:
::
::
::(*) Useless due to the duplication of one of the colors.
:*Mode 4, palette #2, high intensity:
::
::The sixteen combinations with the background color are:
::
::
::(*) Useless due to the duplication of one of the colors.
:*Mode 5, low intensity:
::
::The sixteen combinations with the background color are:
::
::
::(*) Useless due to the duplication of one of the colors.
:*Mode 5, high intensity:
::
::The sixteen combinations with the background color are:
::
::
::(*) Useless due to the duplication of one of the colors.
:When viewed in a monochrome composite monitor, the mode 5 palettes above are shown as a (more or less brighter) 2-bit grayscale palette:
::
* 2-color palette mode
In the 640×200 graphic mode (BIOS mode number 6), every pixel has only a single bit. The foreground color can be set, with the default being white.
:
::
::The sixteen combinations are:
::
::
PCjr and Tandy 1000 series
The
IBM PCjr
The IBM PCjr (pronounced "PC junior") was a home computer produced and marketed by IBM from March 1984 to May 1985, intended as a lower-cost variant of the IBM PC with hardware capabilities better suited for video games, in order to compete mor ...
features a "CGA Plus" video subsystem, consisting mainly of a 6845 CRTC and an LSI video chip known as the "
Video Gate Array
Tandy Graphics Adapter (TGA, also Tandy graphics) is a computer display standard for the Tandy 1000 series of IBM PC compatibles, which has compatibility with the video subsystem of the IBM PCjr but became a standard in its own right.
PCjr grap ...
", that can show all 16 CGA colors simultaneously on screen in the extended low-res graphic modes. The near-compatible
Tandy 1000
The Tandy 1000 is the first in a line of IBM PC workalike home computer systems produced by the Tandy Corporation for sale in its Radio Shack and Radio Shack Computer Center chains of stores.
Overview
In December 1983, an executive with Tand ...
series features almost 100% PCjr-compatible video hardware implemented in a Tandy proprietary chip. This graphics adapter is better known by the name
Tandy Graphics Adapter
Tandy Graphics Adapter (TGA, also Tandy graphics) is a computer display standard for the Tandy 1000 series of IBM PC compatibles, which has compatibility with the video subsystem of the IBM PCjr but became a standard in its own right.
PCjr grap ...
, because the PCjr was short-lived but the Tandy 1000 line was quite popular for many years. The video mode capabilities of early-model Tandy 1000 computers are exactly the same as the PCjr's. (Later Tandy 1000 models featured "Tandy Video II" hardware which added a 640x200 16-color mode but surrendered PCjr hardware register-compatibility for CGA register-compatibility.)
The PCjr adds three video modes to the CGA mode set: 160×200 16-color "low-resolution" graphics, 320×200 16-color "medium-resolution" graphics, and 640×200 4-color "high-resolution" graphics. All PCjr/Tandy 1000 graphics modes can reassign any color index to any palette entry, allowing free selection of all palette
colors in modes with fewer than 16 colors (including the plain CGA modes) and enabling color cycling effects in all modes. The PCjr also offers a graphics blink function which causes 8 colors to alternate between the low and high halves of the 16-color palette at the text blink rate. (A PCjr must be upgraded with a PCjr-specific internal 64 KB memory expansion card in order to use the latter two of these modes or any 80-column text mode. Tandy 1000 base models can use all video modes.)
:
Thomson
For
Thomson computers
In the 1980s the French Thomson company produced a range of 8-bit computers based on the 6809E CPU.
They were released in several variations (mostly concerning the keyboard or color of the casing) covering the MO and TO series from late 1982 to 1 ...
, a popular brand in France, the most common display modes are 320×200, with 8×1 attribute cells with 2 colors. Here the intensity byte affects saturation and not only brightness variations.
Thomson MO5
The
Thomson MO5
The Thomson MO5 is a home computer introduced in France in June 1984 to compete against systems such as the ZX Spectrum and Commodore 64. It had a release price of 2390 FF.
At the same time, Thomson also released the up-market Thomson TO7/ ...
generated graphics based on a EFGJ03L (or MA4Q-1200) gate array capable of 40×25 text display and a resolution of 320 x 200 pixels with 16 colours (subject to proximity constraints - only two colors for a 8x1 pixel area).
The colour palette has 8 basic RGB colours with an intensity bit (called P for "Pastel") that controlled saturation ("saturated" or "pastel").
In memory, the bit order was PBGR. The desaturated colours were obtained by mixing of the original RGB components within the video hardware. This is done by a PROM circuit, where a two bit mask controls colour mixing ratios of 0%, 33%, 66% and 100% of the saturated hue.
This approach allows the display of Orange instead of "desaturated white", and Gray instead of "desaturated black".
According to the values specified on the computer's technical manual (“Manuel Technique du MO5”,
pg. 11 & 19), the hardware palette was:
''Displayed colors are only approximate due to different transfer and color spaces used on web pages (sRGB
sRGB is a standard RGB (red, green, blue) color space that HP and Microsoft created cooperatively in 1996 to use on monitors, printers, and the World Wide Web. It was subsequently standardized by the International Electrotechnical Commission ...
) and analog video (BT.601
ITU-R Recommendation BT.601, more commonly known by the abbreviations Rec. 601 or BT.601 (or its former name CCIR 601) is a standard originally issued in 1982 by the CCIR (an organization, which has since been renamed as the Internatio ...
)''
Actual colour on emulators and later models seems to have been tweaked, with normal Blue and Red being fully saturated.
:
Thomson TO7/70
The
Thomson TO7/70 Thomson may refer to:
Names
* Thomson (surname), a list of people with this name and a description of its origin
* Thomson baronets, four baronetcies created for persons with the surname Thomson
Businesses and organizations
* SGS-Thomson Mi ...
graphics were similar to the
Thomson MO5
The Thomson MO5 is a home computer introduced in France in June 1984 to compete against systems such as the ZX Spectrum and Commodore 64. It had a release price of 2390 FF.
At the same time, Thomson also released the up-market Thomson TO7/ ...
and generated by a
Motorola
Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent public companies, Motorola ...
MCA1300
gate array
A gate array is an approach to the design and manufacture of application-specific integrated circuits (ASICs) using a prefabricated chip with components that are later interconnected into logic devices (e.g. NAND gates, flip-flops, etc.) accord ...
. capable of 40×25 text display and a resolution of 320 x 200 pixels with 16 colours (limited by 8x1 pixel colour attribute areas). The colour palette is
4-bit RGBI, with 8 basic RGB colours and a intensity bit (called P for "Pastel") that controlled saturation ("saturated" or "pastel").
Fixed color palette 1 (similar to MO5)
:
:
Fixed color palette 2
:
:
Fixed color palette 3
:
:
Mattel Aquarius
The
Mattel Aquarius
Aquarius is a home computer designed by Radofin and released by Mattel Electronics in 1983. Based on the Zilog Z80 microprocessor, the system has a rubber chiclet keyboard, 4K of RAM, and a subset of Microsoft BASIC in ROM. It connects to a te ...
computer has only a text mode with 40×24 characters, which graphic mode is obtained from low resolution blocks, providing an 80×72 resolution. The color attribute area is also on this 40×24 characters area, and used from a pixel group of 2×3. The machine uses a
TEA1002 The TEA1002 is a PAL video encoder chip produced by Mullard in 1982 and used on the Mattel Aquarius and AlphaTantel computers.
It was also used on teletext decoders and color bar generators associated with video test equipment
The chip is capab ...
graphic chip, with a fixed palette of 8 RGB colors with an intensity variation (reducing brightness and saturation of any given color)
:
:
3 level RGB palettes
Amstrad CPC series
The
Amstrad
Amstrad was a British electronics company, founded in 1968 by Alan Sugar at the age of 21. The name is a contraction of Alan Michael Sugar Trading. It was first listed on the London Stock Exchange in April 1980. During the late 1980s, Amstra ...
CPC 464
The CPC 464 is the first personal home computer built by Amstrad in 1984. It was one of the bestselling and best produced microcomputers, with more than 2 million units sold in Europe. The British microcomputer boom had already peaked before Am ...
/
664
__NOTOC__
Year 664 ( DCLXIV) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar. The denomination 664 for this year has been used since the early medieval period, when the Anno Domini calendar era be ...
/
6128 series of computers generates the available palette with
3 levels (not bits) for every RGB primary. Thus, there are 27 different RGB combinations, from which 16 can be simultaneously displayed in low resolution mode, four in medium resolution mode and two in high resolution mode.
:
Simulations of actual images on the Amstrad's color monitor in each of the modes (160×200x16 colors; 320×200x4 colors and 640×200x2 colors) follows. A cheaper green monochrome display was also available from the manufacturer; in this case, the colors are viewed as a 16-tone green scale, as shown in the last simulated image, as it interprets the overall brightness of the full color signal, instead of only considering the green intensity as might, e.g., the ''Philips CM8833'' line.
:
:
The number in parentheses means the primary ink number for the
Locomotive BASIC PEN, PAPER and INK statements (that is, "(1)" means ink #1 defaults to this color). Inks can also have a secondary color number, meaning they flash between two colors. By default, ink #14 alternates between colors 1 and 24 (blue and bright yellow) and ink #15 alternates between colors 11 and 16 (cyan-blue and pink). In addition, the paper defaults to ink #0 and the pen to ink #1, meaning yellow text on a dark blue background.
8-bit RGB palettes
:
The 8-bit RGB palettes (also known as 3-3-2 bit RGB) use 3 bits for each of the red and green color components, and 2 bits for the blue component, due to the lesser sensitivity of the common human eye to this primary color. This results in an 8×8×4 = 256-color palette as follows:
:
:
Tiki 100
The
Tiki 100
Tiki-100 was a desktop home/personal computer manufactured by Tiki Data of Oslo, Norway. The computer was launched in the spring of 1984 under the original name Kontiki-100, and was first and foremost intended for the emerging educational sector ...
uses a 8-bit RGB palette (also described as 3-3-2 bit RGB), with 3 bits for each of the red and green color components, and 2 bits for the blue component.
It supports 3 different resolutions with 256, 512 or 1024 by 256 pixels and 16, 4, or 2 colors respectively (freely selectable from the full 256 color palette).
Enterprise
The
Enterprise
Enterprise (or the archaic spelling Enterprize) may refer to:
Business and economics
Brands and enterprises
* Enterprise GP Holdings, an energy holding company
* Enterprise plc, a UK civil engineering and maintenance company
* Enterprise ...
computer has five graphics modes: 40- and 80-column text modes, Lo-Res and Hi-Res bit mapped graphics, and attribute graphics. Bit mapped graphics modes allow selection between displays of 2, 4,16 or 256 colors (from a 3-3-2 bit RGB palette), but horizontal resolution decreases as color depth increases.
Interlaced and non-interlaced modes are available. The maximum resolution is 640×512 pixels interlaced, or 640×256 pixels non-interlaced. These resolutions permit only a 2-colour display.
A 256-colour display has a maximum resolution of 80×256. The attribute graphics mode provides a 320×256 pixel resolution with 16 colors, selectable from a palette of 256.
Multiple pages can be displayed simultaneously on the screen, even if their graphics modes are different. Each page has its own palette, which allows more colors to be displayed onscreen simultaneously. The page height can be larger than the screen or the window it is displayed on. Each page is connected to a channel of the EXOS operating system, so it is possible to write on a hidden page.
MSX2
On the
MSX2
MSX is a standardized home computer architecture, announced by Microsoft and ASCII Corporation on June 16, 1983. It was initially conceived by Microsoft as a product for the Eastern sector, and jointly marketed by Kazuhiko Nishi, then vice- ...
screen mode 8 is a high-resolution 256×212-pixel mode with an 8-bit color depth, giving a palette of 256 colors (''Fixed RGB'' mode of the
Yamaha V9938
The Yamaha V9938 is a video display processor (VDP) used on the MSX2 home computer, as well as on the Geneve 9640 enhanced TI-99/4A clone and the Tatung Einstein 256. It was also used in a few MSX1 computers, in a configuration with 16kB VRAM ...
video chip). From the MSB to LSB, there are three green bits, three red bits, and two blue bits. This mode uses half of the available colors overall, and can be considered a palette in its own right.
:
9-bit RGB palettes
The
MSX2
MSX is a standardized home computer architecture, announced by Microsoft and ASCII Corporation on June 16, 1983. It was initially conceived by Microsoft as a product for the Eastern sector, and jointly marketed by Kazuhiko Nishi, then vice- ...
series features a
Yamaha V9938
The Yamaha V9938 is a video display processor (VDP) used on the MSX2 home computer, as well as on the Geneve 9640 enhanced TI-99/4A clone and the Tatung Einstein 256. It was also used in a few MSX1 computers, in a configuration with 16kB VRAM ...
video chip, which manages a
9-bit RGB palette (512 colors in ''Paletted RGB'' mode) and has some extended graphic modes. Although its graphical capabilities are similar, or even better than of those of
16-bit
16-bit microcomputers are microcomputers that use 16-bit microprocessors.
A 16-bit register can store 216 different values. The range of integer values that can be stored in 16 bits depends on the integer representation used. With the two mos ...
personal computer
A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tech ...
s, MSX2 and MSX2+ (see below) are pure 8-bit machines.
:
Screen mode 6 is a 512×212-pixel mode with a 4-color palette chosen from the available 512 colors.
Screen modes 5 and 7 are high-resolution 256×212-pixel and 512×212-pixel modes, respectively, with a 16-color palette chosen from the available 512 colors. Each pixel can be any of the 16 selected colors.
:
15-bit RGB palettes
MSX2+
The
MSX2+
MSX is a standardized home computer architecture, announced by Microsoft and ASCII Corporation on June 16, 1983. It was initially conceived by Microsoft as a product for the Eastern sector, and jointly marketed by Kazuhiko Nishi, then vice-p ...
series (released in 1988) features a
Yamaha V9958
The Yamaha V9958 is a Video Display Processor used in the MSX2+ and MSX turbo R series of home computers, as the successor to the Yamaha V9938 used in the MSX2. The main new features are three graphical YJK modes with up to 19268 colors and ...
video chip which manages a
15-bit RGB palette internally encoded in
YJK
YJK is a proprietary color space implemented by the Yamaha V9958 graphic chip on MSX2+ computers. It has the advantage of encoding images by implementing less resolution for color information than for brightness, taking advantage of the human vi ...
(up to 19,268 different colors from the 32,768 theoretically possible) and has additional screen modes. Although its graphical capabilities are similar, or even better than of those of
16-bit
16-bit microcomputers are microcomputers that use 16-bit microprocessors.
A 16-bit register can store 216 different values. The range of integer values that can be stored in 16 bits depends on the integer representation used. With the two mos ...
personal computer
A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tech ...
s, MSX2 (see above) and MSX2+ are pure 8-bit machines. YJK color encoding can be viewed as a
lossy compression
In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size ...
technique; in the RGB to YJK conversion, the average red and green levels are preserved, but blue is subsampled. As a result of every four pixels sharing a chroma value, in mode 12 it is not possible to have vertical lines of a single color. This is only possible in modes 10 and 11 due to the additional 16-color direct palette. This can be used to mix 16 indexed colors with a rich colorful background, in what can be considered a primitive
video overlay {{Distinguish, on-screen display
Video overlay is any technique used to display a video window on a computer display while bypassing the chain of CPU to graphics card to computer monitor. This is done in order to speed up the video display, and it ...
technique.
:
Screen modes 10 & 11 – 12,499 YJK colors plus a 16-color palette. In this mode, the YJK technique encodes 16 levels of luminance into the four LSBs of each pixel and 64 levels of chroma, from −32 to +31, shared across every four consecutive pixels and stored in the three higher bits of the four pixels. If the fifth bit of the pixel is set, then the lower four bits of the pixel points to an index in the 16-color palette; otherwise, they specify the YJK luminance level of the pixel.
Screen mode 12 is similar to modes 10 and 11, but uses five bits to encode 32 levels of luminance for every pixel, thus it does not use an additional palette and, with YJK encoding, 19,268 different colors can be displayed simultaneously with 8-bit color depth.
:
18-bit RGB palettes
Fujitsu
Fujitsu
is a Japanese multinational information and communications technology equipment and services corporation, established in 1935 and headquartered in Tokyo. Fujitsu is the world's sixth-largest IT services provider by annual revenue, and the la ...
's
FM-77 AV 40, released in 1986, uses an
18-bit RGB palette. Any 64,000 out of 262,144 colors can be displayed simultaneously at the 320×200 resolution, or 8 out of 262,144 colors at the 640×400 resolution.
:
Composite video palettes
This section covers systems that generate color directly as
composite video
Composite video is an analog video signal format that carries standard-definition video (typically at 525 lines or 625 lines) as a single channel. Video information is encoded on one channel, unlike the higher-quality S-Video (two channe ...
, closely related with display on analog
CRT
CRT or Crt may refer to:
Science, technology, and mathematics Medicine and biology
* Calreticulin, a protein
*Capillary refill time, for blood to refill capillaries
*Cardiac resynchronization therapy and CRT defibrillator (CRT-D)
* Catheter-re ...
TVs. Many of the colors are non-standard and outside of RGB
gamut
In color reproduction, including computer graphics and photography, the gamut, or color gamut , is a certain ''complete subset'' of colors. The most common usage refers to the subset of colors which can be accurately represented in a given circ ...
, and would only display properly on
NTSC
The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
hardware.
Due to the varying ways of converting a composite signal to
sRGB
sRGB is a standard RGB (red, green, blue) color space that HP and Microsoft created cooperatively in 1996 to use on monitors, printers, and the World Wide Web. It was subsequently standardized by the International Electrotechnical Commission ...
(the standard for internet images), images in this section will be inconsistent with each other in color until further notice.
Atari 400/800/XL/XE
The early
Atari 400 and 800 computers use a palette of 128 colors (a bit similar to the one used on the
Atari 2600
The Atari 2600, initially branded as the Atari Video Computer System (Atari VCS) from its release until November 1982, is a home video game console developed and produced by Atari, Inc. Released in September 1977, it popularized microprocess ...
console, and the
Commodore 16
The Commodore 16 is a home computer made by Commodore International with a 6502-compatible 7501 or 8501 CPU, released in 1984 and intended to be an entry-level computer to replace the VIC-20. A cost-reduced version, the Commodore 116, was ...
and
Plus/4
The Commodore Plus/4 is a home computer released by Commodore International in 1984. The "Plus/4" name refers to the four-application ROM resident office suite (word processor, spreadsheet, database, and graphing); it was billed as "the produc ...
), using 4 bits for chrominance, and 3 for luminance. Screen modes may vary from 320×192 (384x240 with
overscan
Overscan is a behaviour in certain television sets, in which part of the input picture is shown outside of the visible bounds of the screen. It exists because cathode-ray tube (CRT) television sets from the 1930s through to the early 2000s were h ...
) to 40×24, using 2 or 4 simultaneous colors, or 80×192 (96x240 with
overscan
Overscan is a behaviour in certain television sets, in which part of the input picture is shown outside of the visible bounds of the screen. It exists because cathode-ray tube (CRT) television sets from the 1930s through to the early 2000s were h ...
) using 16 colors. After 2 years (late 1981) the CTIA graphics chip was replaced with the GTIA chip thus increasing the palette to 256 colors (
CTIA and GTIA
Color Television Interface Adaptor (CTIA) and its successor Graphic Television Interface Adaptor (GTIA) are custom chips used in the Atari 8-bit family of computers and in the Atari 5200 home video game console. In these systems, a CTIA or GTIA ch ...
).
The
ANTIC
Alphanumeric Television Interface Controller (ANTIC) is an LSI ASIC dedicated to generating 2D computer graphics to be shown on a television screen or computer display. Under the direction of Jay Miner, the chip was designed in 1977-1978 by ...
chip in the
Atari 8-bit family
The Atari 8-bit family is a series of 8-bit home computers introduced by Atari, Inc. in 1979 as the Atari 400 and Atari 800. The series was successively upgraded to Atari 1200XL , Atari 600XL, Atari 800XL, Atari 65XE, Atari 130XE, Atari 800XE ...
computers (400, 800, XL and XE models) has an instruction set to run programs (called
display list A display list (or ''display file'') is a series of graphics commands that define an output image. The image is created ( ''rendered'') by executing the commands to combine various primitives. This activity is most often performed by specialized di ...
) which permits many more colors on the screen at once. There are a number of possible software-driven graphics modes.
CTIA palette
:
GTIA palette
Apple II series
The
Apple II
The Apple II (stylized as ) is an 8-bit home computer and one of the world's first highly successful mass-produced microcomputer products. It was designed primarily by Steve Wozniak; Jerry Manock developed the design of Apple II's foam-mold ...
series features a 16-color
composite video
Composite video is an analog video signal format that carries standard-definition video (typically at 525 lines or 625 lines) as a single channel. Video information is encoded on one channel, unlike the higher-quality S-Video (two channe ...
palette, based on the
YIQ
YIQ is the color space used by the analog NTSC color TV system, employed mainly in North and Central America, and Japan.
''I'' stands for ''in-phase'', while ''Q'' stands for ''quadrature'', referring to the components used in quadrature amplitu ...
color space used by the NTSC color TV system.
The Apple II features "low-res" and "hi-res" modes. The 40x48 pixel lo-res mode allowed 15 different colors plus a duplicate gray(**).
*
The majority of Apple graphic applications used the hi-res mode, which had 280×192 pixels (effectively 140x192 on a color monitor). The hi-res mode allowed six colors: black, white, blue, orange, green and purple.
Low-res mode palette
:
:
:* Note: Colors with italic text and marked with three
asterisks
The asterisk ( ), from Late Latin , from Ancient Greek , ''asteriskos'', "little star", is a typographical symbol. It is so called because it resembles a conventional image of a heraldic star.
Computer scientists and mathematicians often vo ...
(***) are out of the
RGB
The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additiv ...
gamut
In color reproduction, including computer graphics and photography, the gamut, or color gamut , is a certain ''complete subset'' of colors. The most common usage refers to the subset of colors which can be accurately represented in a given circ ...
.
High-res mode palette
:
:
Systems based on MOS Technology chips
For all the following computers from Commodore, the U and V coordinates for the
composite video
Composite video is an analog video signal format that carries standard-definition video (typically at 525 lines or 625 lines) as a single channel. Video information is encoded on one channel, unlike the higher-quality S-Video (two channe ...
colors are always the
cosine and the sine, respectively, of angles multiple of 22.5 degrees (i.e. a quarter of 90°), as the engineers were inspired by the
NTSC
The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
color wheel, a radial way to figure out the U and V coordinates of points equidistant from the center of the chroma plane, the gray. Consumers in Europe (which uses PAL) considered the Commodore colors to be more "washed out" and less vivid than those provided by computers such as the
ZX Spectrum
The ZX Spectrum () is an 8-bit home computer that was developed by Sinclair Research. It was released in the United Kingdom on 23 April 1982, and became Britain's best-selling microcomputer.
Referred to during development as the ''ZX81 Colou ...
.
VIC-20
The
VIC-20
The VIC-20 (known as the VC-20 in Germany and the VIC-1001 in Japan) is an 8-bit home computer that was sold by Commodore Business Machines. The VIC-20 was announced in 1980, roughly three years after Commodore's first personal computer, the ...
uses a
MOS Technology VIC
The VIC (Video Interface Chip), specifically known as the MOS Technology 6560 ( NTSC version) / 6561 ( PAL version), is the integrated circuit chip responsible for generating video graphics and sound in the VIC-20 home computer from Commodore. ...
chip which produces a 16-color
YPbPr
YPbPr or Y'PbPr, also written as , is a color space used in video electronics, in particular in reference to component video cables. YPBPR is gamma corrected YCBCR color space (it is not analog YUV that was used for analog TV, though componen ...
composite video
Composite video is an analog video signal format that carries standard-definition video (typically at 525 lines or 625 lines) as a single channel. Video information is encoded on one channel, unlike the higher-quality S-Video (two channe ...
palette.
[ 090420 fpgaarcade.com] The palette lacks any intermediate shade of gray, and it has 5 or 9 levels of luminance.
The VIC-20 lacks any true graphic mode, but a 22×11 text mode with 200 definable characters of 8×16 bits each arranged as a matrix of 20×10 characters is usually used instead, giving a 3:2(NTSC)/5:3(PAL) pixel aspect ratio, 160×160 pixels, 8-color "high-res mode" or a 3:1(NTSC)/10:3(PAL) pixel aspect ratio, 80×160 pixels, 10-color "multicolor mode".
:
In the 8-color ''high-res mode'', every 8×8 pixels can have the background color (shared for the entire screen) or a free foreground color, both selectable among the first eight colors of the palette. In the 10-color ''multicolor mode'', a single pixel of every 4×8 block (a character cell) may have any of four colors: the background color, the auxiliary color (both shared for the entire screen and selectable among the entire palette), the same color as the overscan border (also a shared color) or a free foreground color, both selectable among the first eight colors of the palette.
Simulated images
:
On some models of the system, there are nine levels of luminance:
:
But on other models, there are only five levels of luminance:
:
Commodore 64
The
MOS Technology VIC-II
The VIC-II (Video Interface Chip II), specifically known as the MOS Technology 6567/8562/8564 (NTSC versions), 6569/8565/8566 (PAL), is the microchip tasked with generating Y/C video signals (combined to composite video in the RF modulator) and ...
is used in the
Commodore 64 (and
Commodore 128
The Commodore 128, also known as the C128, C-128, C= 128,The "C=" represents the graphical part of the logo. is the last 8-bit home computer that was commercially released by Commodore Business Machines (CBM). Introduced in January 1985 at the ...
in 40-column mode), and features a 16-color
YPbPr
YPbPr or Y'PbPr, also written as , is a color space used in video electronics, in particular in reference to component video cables. YPBPR is gamma corrected YCBCR color space (it is not analog YUV that was used for analog TV, though componen ...
composite video
Composite video is an analog video signal format that carries standard-definition video (typically at 525 lines or 625 lines) as a single channel. Video information is encoded on one channel, unlike the higher-quality S-Video (two channe ...
palette. This palette is largely based on that of the VIC, but it substitutes three colors by three levels of gray. When displayed over an analog NTSC composite video output, the actual resulting colors are more vivid.
:
The Commodore 64 has two graphic modes: Multicolor and High Resolution.
In the Multicolor 160×200, 16-color mode, every cell of 4×8, 2:1 aspect ratio pixels can have one of four colors: one shared with the entire screen, the two background and foreground colors of the corresponding text mode character, and one more color also stored in the color RAM area, all of them freely selectable among the entire palette.
In the High Resolution 320×200, 16-color mode, every cell of 8×8 pixels can have one of the two background and foreground colors of the correspondent text mode character, both freely selectable among the entire palette.
Simulated images
:
On most models of the Commodore 64, there are nine levels of luminance:
:
Commodore 16 and Plus/4
The
MOS Technology TED
The 7360/8360 Text Editing Device (TED) was an integrated circuit made by MOS Technology, Inc. It was a video chip that also contained sound generation hardware, DRAM refresh circuitry, interval timers, and keyboard input handling. It was de ...
was used in the
Commodore 16
The Commodore 16 is a home computer made by Commodore International with a 6502-compatible 7501 or 8501 CPU, released in 1984 and intended to be an entry-level computer to replace the VIC-20. A cost-reduced version, the Commodore 116, was ...
and
Commodore Plus/4
The Commodore Plus/4 is a home computer released by Commodore International in 1984. The "Plus/4" name refers to the four-application ROM resident office suite (word processor, spreadsheet, database, and graphing); it was billed as "the produc ...
. It has a palette of 121
YPbPr
YPbPr or Y'PbPr, also written as , is a color space used in video electronics, in particular in reference to component video cables. YPBPR is gamma corrected YCBCR color space (it is not analog YUV that was used for analog TV, though componen ...
composite video
Composite video is an analog video signal format that carries standard-definition video (typically at 525 lines or 625 lines) as a single channel. Video information is encoded on one channel, unlike the higher-quality S-Video (two channe ...
colors consisting of sixteen hues (including black and white) at eight luminance levels. Black is the same color at every luminance level, so there are not 128 different colors. On the Commodore Plus/4, twelve colors formed a "default" palette of sorts accessible through keyboard shortcuts; these colors are underlined in the table below (
RGB
The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additiv ...
converted colors at a saturation level of 34%).
:
The Commodore 16 and Commodore Plus/4 have two graphic modes very similar to those of the Commodore 64: Multicolor and High Resolution.
In the Multicolor 160×200, 121-color mode, every cell of 4×8, 2:1 aspect ratio pixels can have one of four colors: two shared with the entire screen and the two background and foreground colors of the correspondent text mode character, all of them freely selectable among the entire 121-color palette (hue 0 to 15 and luminance 0 to 7 are set individually for any of them).
In the High Resolution 320×200, 121-color mode, every cell of 8×8 pixels can have one of the two background and foreground colors of the corresponding text mode character, both freely selectable among the entire 121-color palette (again setting both the hue and the luminance).
Simulated images
:
:
Notes:
* Every composite color marked with an
asterisk
The asterisk ( ), from Late Latin , from Ancient Greek , ''asteriskos'', "little star", is a typographical symbol. It is so called because it resembles a conventional image of a heraldic star.
Computer scientists and mathematicians often vo ...
(*) is out of the
RGB
The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additiv ...
gamut
In color reproduction, including computer graphics and photography, the gamut, or color gamut , is a certain ''complete subset'' of colors. The most common usage refers to the subset of colors which can be accurately represented in a given circ ...
.
Systems based on the Texas Instruments TMS9918 chip
The
TMS9918
VDP TMS9918A
VDP TMS9918A
VDP TMS9928A
The TMS9918 is a video display controller (VDC) manufactured by Texas Instruments, in manuals referenced as 'Video Display Processor' (VDP) and introduced in 1979. The TMS9918 and its variants were used ...
is a
Video Display Controller
A video display controller or VDC (also called a display engine or display interface) is an integrated circuit which is the main component in a video-signal generator, a device responsible for the production of a TV video signal in a computin ...
(VDC) manufactured by
Texas Instruments
Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globa ...
and introduced in 1979. The TMS9918 and its variants were used in the
Memotech MTX
The Memotech MTX500, MTX512 and RS128 are a series of Zilog Z80A processor-based home computers released by Memotech in 1983 and 1984.
Design
The MTX500 had 32 KB of RAM, the MTX512 had 64KB, and the RS128 had 128KB. Although the Z80A coul ...
,
MSX
MSX is a standardized home computer architecture, announced by Microsoft and ASCII Corporation on June 16, 1983. It was initially conceived by Microsoft as a product for the Eastern sector, and jointly marketed by Kazuhiko Nishi, then vice-p ...
,
Sord M5
The Sord M5 is a home computer launched by Sord Computer Corporation in 1982. Primarily the Sord M5 competed in the Japanese home computer market. It was also sold as the CGL M5 in the United Kingdom by Computer Games Limited and was reasonably ...
,
Tatung Einstein
The Tatung Einstein was an eight-bit home/personal computer produced by Taiwanese corporation Tatung, designed in Bradford, England at Tatung's research laboratories and assembled in Bridgnorth and Telford, England. It was aimed primarily at ...
and
Tomy Tutor
The Tomy Tutor, originally sold in Japan as the and in the UK as the Grandstand Tutor, is a home computer produced by the Japanese toymaker Tomy. It is architecturally similar, but not identical, to the TI-99/4A, and uses a similar Texas Instrum ...
.
The TMS9918 chip which uses a proprietary 15-color
YUV
YUV is a color model typically used as part of a color image pipeline. It encodes a color image or video taking human perception into account, allowing reduced bandwidth for chrominance components, compared to a "direct" RGB-representation. ...
composite video
Composite video is an analog video signal format that carries standard-definition video (typically at 525 lines or 625 lines) as a single channel. Video information is encoded on one channel, unlike the higher-quality S-Video (two channe ...
palette encoded palette plus a ''transparent'' color, intended to be used by the hardware
sprites and simple
video overlay {{Distinguish, on-screen display
Video overlay is any technique used to display a video window on a computer display while bypassing the chain of CPU to graphics card to computer monitor. This is done in order to speed up the video display, and it ...
. When used as an ordinary background color, it is rendered using the same color as the screen border.
:
:
:Note: The colors inside the parentheses are out of RGB gamut.
MSX
The MSX series has two graphic modes. The
MSX BASIC
MSX BASIC is a dialect of the BASIC programming language. It is an extended version of Microsoft's MBASIC Version 4.5, adding support for graphic, music, and various peripherals attached to MSX microcomputers. Generally, MSX BASIC is designed to ...
Screen 3 mode is a low-resolution mode with 15 colors, in which every pixel can be any of the 15 available colors.
Screen mode 2 is a 256×192 high-resolution mode with 15 colors, in which each of every eight consecutive pixels can only use 2 colors.
:
Systems based on the Motorola 6847 chip
The
Motorola 6847
The MC6847 is a video display generator (VDG) first introduced by Motorola and used in the TRS-80 Color Computer, Dragon 32/64, Laser 200, TRS-80 MC-10/Matra Alice, NEC PC-6000 series, Acorn Atom, and the APF Imagination Machine, among others. I ...
is a video display generator (VDG) first introduced by
Motorola
Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent public companies, Motorola ...
and used in the
TRS-80 Color Computer
The RadioShack TRS-80 Color Computer, later marketed as the Tandy Color Computer and sometimes nicknamed the CoCo, is a line of home computers developed and sold by Tandy Corporation. Despite sharing a name with the earlier TRS-80, the Color Co ...
,
Dragon 32/64
The Dragon 32 and Dragon 64 are home computers that were built in the 1980s. The Dragons are very similar to the TRS-80 Color Computer, and were produced for the European market by Dragon Data, Ltd., initially in Swansea, Wales before m ...
,
Laser 200
The VTech Laser 200 is an 8-bit home computer from 1983, also sold as the Salora Fellow (mainly in Fennoscandia, particularly Finland), the Seltron 200 in Hungary and Italy, the Smart-Alec Jr. by Dynasty Computer Corporation in Dallas, Texa ...
,
TRS-80 MC-10
The TRS-80 MC-10 microcomputer is a lesser-known member of the TRS-80 line of home computers, produced by Tandy Corporation in the early 1980s and sold through their RadioShack chain of electronics stores. It was a low-cost alternative to Tandy ...
,
NEC PC-6000 series,
Acorn Atom
The Acorn Atom is a home computer made by Acorn Computers Ltd from 1980 to 1982, when it was replaced by the BBC Micro. The Micro began life as an upgrade to the Atom, originally known as the Proton.
The Atom was a progression of the MOS Techn ...
, and the
APF Imagination Machine
The APF Imagination Machine is a combination home video game console and home computer system released by APF Electronics Inc. in late 1979. It has two separate components, the APF-M1000 game system, and an add-on docking bay with full sized ty ...
, among others.
:
Color is generated by the combination of three signals, Y with 6 possible levels, Pr and Pb with 3 possible levels, based on the
YPbPr
YPbPr or Y'PbPr, also written as , is a color space used in video electronics, in particular in reference to component video cables. YPBPR is gamma corrected YCBCR color space (it is not analog YUV that was used for analog TV, though componen ...
colorspace
A color space is a specific organization of colors. In combination with color profiling supported by various physical devices, it supports reproducible representations of colorwhether such representation entails an analog or a digital represent ...
, and then converted for output into a
NTSC
The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...
analog signal:
TRS-80 Color Computer
The
TRS-80 Color Computer
The RadioShack TRS-80 Color Computer, later marketed as the Tandy Color Computer and sometimes nicknamed the CoCo, is a line of home computers developed and sold by Tandy Corporation. Despite sharing a name with the earlier TRS-80, the Color Co ...
is capable of displaying text and graphics contained within a roughly square display matrix 256 pixels wide by 192 lines high.
The hardware palette has 9 colors: black, green, yellow, blue, red, buff (almost-but-not-quite white), cyan, magenta, and orange.
All colors are available in text modes. In color modes (64×64, 128×64, 128×96, and 128×192) two four color palettes are available:
a green border with the colors green, yellow, red, and blue;
a white border with the colors white, cyan, magenta, and orange.
Display modes
:
NEC PC-6000 series
Similar to other computers using the same video chip, the
NEC PC-6000 series had four screen modes:
* 32x16 characters with 4 colors
* 64x48 pixel graphics with 9 colors
* 128x192 graphics with 4 colors
* 256x192 graphics with 2 colors (green, white)
Other palettes
Tandy Color Computer 3
The
Tandy Color Computer
The RadioShack TRS-80 Color Computer, later marketed as the Tandy Color Computer and sometimes nicknamed the CoCo, is a line of home computers developed and sold by Tandy Corporation. Despite sharing a name with the earlier TRS-80, the Color Com ...
3 could display all of the modes of the Tandy Color Computer 1 and 2, except the Semigraphics modes, plus resolutions of 160, 256, 320, or 640 pixels wide by 192 to 225 lines from a palette of 64 colors. The 320 mode allowed 16 simultaneous colors, while the 640 mode allowed 4.
:
SAM Coupé
The 128 color master palette used by the
SAM Coupé
Sam, SAM or variants may refer to:
Places
* Sam, Benin
* Sam, Boulkiemdé, Burkina Faso
* Sam, Bourzanga, Burkina Faso
* Sam, Kongoussi, Burkina Faso
* Sam, Iran
* Sam, Teton County, Idaho, United States, a populated place
People and fictiona ...
is produced via a unique method — it effectively contains 2 groups of 64 "RGB" colors of mildly different intensity, and ultimately derived from a 512 color space.
The closest equivalent in more popular and well-known machines would be the Commodore-Amiga's 64-color "Extra Half-Brite" mode (with 32 explicitly set colors using 5 bitplanes, which are displayed with full or half brightness depending on the bit setting of a 6th plane).
Two bits are used for each of Red, Green and Blue and give a similar result to a normal 6-bit RGB palette (as seen with the IBM EGA or Sega Master System); the seventh bit encodes for "brightness", which has a similar but more subtle effect to the Spectrum, increasing the output of all three channels by half the intensity of the lower bits of the main six (in this way, it does make a genuine 128 colors — rather than 127 colors with "two blacks" and only a 7-level grayscale). The layout of the byte that encodes each color is complicated and appears like a Spectrum color nybble transferred to a full byte's width, and an extra RGB bit-triplet then prefixed to it, with the MSB left unused.
:
:
Side-by-side comparison
Since there are many 8-bit computers to compare, a comparison table has been compiled to make comparing the systems easier.
See also
*
List of color palettes
This article is a list of the color palettes for notable computer graphics, terminals and video game console hardware.
Only a sample and the palette's name are given here. More specific articles are linked from the name of each palette, for the ...
*
List of monochrome and RGB color formats
This list of monochrome and RGB palettes includes generic repertoires of colors ( color palettes) to produce black-and-white and RGB color pictures by a computer's display hardware. RGB is the most common method to produce colors for displays; ...
*
List of software palettes This is a list of software palettes used by computers. Systems that use a 4-bit or 8-bit pixel depth can display up to 16 or 256 colors simultaneously. Many personal computers in the early 1990s displayed at most 256 different colors, freely s ...
*
List of video game console palettes
This is a full list of color palettes for notable video game console hardware.
For each unique palette, an image color test chart and sample image (original True color version follows) rendered with that palette (without dithering unless ot ...
*
List of 16-bit computer hardware palettes
*
Palette (computing)
In computer graphics, a palette is the set of available colors from which an image can be made. In some systems, the palette is fixed by the hardware design, and in others it is dynamic, typically implemented via a color lookup table (CLUT), ...
*
Indexed color
In computing, indexed color is a technique to manage digital images' colors in a limited fashion, in order to save computer memory and file storage, while speeding up display refresh and file transfers. It is a form of vector quantization comp ...
*
Color Lookup Table
In computer graphics, a palette is the set of available colors from which an image can be made. In some systems, the palette is fixed by the hardware design, and in others it is dynamic, typically implemented via a color lookup table (CLUT), ...
*
Color depth
Color depth or colour depth (see spelling differences), also known as bit depth, is either the number of bits used to indicate the color of a single pixel, or the number of bits used for each color component of a single pixel. When referring ...
References
{{DEFAULTSORT:8-bit computer hardware palettes
Computer graphics
Color depths
Computing output devices