This article has multiple issues. Please help improve it or discuss these issues on the talk page . (Learn how and when to remove these messages)
|
This is a list of notable RGB hardware color palettes used on 16-bit computers, which were primarily manufactured from 1985 to 1995. Due to mixed-bit architectures, the n-bit distinction is not always a strict categorization.
12-bit, 4096-color palette | 0x00 | 0x01 | 0x02 | 0x03 | 0x04 | 0x05 | 0x06 | 0x07 | 0x08 | 0x09 | 0x0A | 0x0B | 0x0C | 0x0D | 0x0E | 0x0F |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
15-bit, 32768-color palette | 0x00 | 0x01 | 0x02 | 0x03 | 0x04 | 0x05 | 0x06 | 0x07 | 0x08 | 0x09 | 0x0A | 0x0B | 0x0C | 0x0D | 0x0E | 0x0F |
0x10 | 0x11 | 0x12 | 0x13 | 0x14 | 0x15 | 0x16 | 0x17 | 0x18 | 0x19 | 0x1A | 0x1B | 0x1C | 0x1D | 0x1E | 0x1F |
The Atari ST series has a digital-to-analog converter of 3-bits, eight levels per RGB channel, featuring a 9-bit RGB palette (512 colors). Depending on the (proprietary) monitor type attached, it displays one of the 320×200, 16-colors and 640×200, 4-colors modes with the color monitor, or the high resolution 640×400 black and white mode with the monochrome monitor.
0 – black | 1 – [user-defined] |
The STE series has a digital-to-analog converter of 4-bits, sixteen levels per RGB channel, featuring a 12-bit RGB palette (4096 colors) (similar to the Commodore Amiga).
The Original Chip Set (OCS) of the Commodore Amiga features a 12-bit RGB, 4,096-color palette. As the Amiga Copper programmable graphics coprocessor is capable of changing color lookup table entries on the fly during display, in practice the number of distinct colors visible on-screen may exceed static color lookup table sizes documented here.
The picture is divided in a series of bit planes, between 1 and 6 for horizontal resolutions of 320 (or up to 384 with overscan), and between 1 and 4 for horizontal resolutions of 640 (or up to 768 with overscan). For either horizontal resolution, the vertical resolution is either 200 (or up to 240 with overscan), or 400 (or up to 480 with overscan) if interlaced, for NTSC-compatible video modes; or 256 (or up to 288 with overscan), or 512 (or up to 576 with overscan) if interlaced, for PAL-compatible video modes. The color lookup table has up to 32 entries. So the different indexed color modes are from 1 to 5 bits pixel depth, 2-, 4-, 8-, 16- or 32-color out of 4,096.
When the sixth bit-plane is used, two extra color modes can be set: Extra Half-Brite (EHB) and Hold-And-Modify (HAM).
In the EHB mode, when the sixth bit is set to on for any given pixel, the display hardware halves the brightness of said pixel. This allows the Amiga to display 64 colors instead of the standard 32, with the caveat being that the 32 extra colors cannot be arbitrarily selected, and must be darker versions of those already being displayed on screen
In the HAM mode, the two higher bits of the 6-bits pixels are used as a four state command. Three of the states changes only the red, green or blue component of the pixel respect of the precedent in the scan line, and hold the other two RGB components. The new value for the modified color component is in the four lower bits. The remaining command state forces the pixel value to be one of the 16 first values of the palette, whose indice is in the four lower bits of the pixel. So it is very important to have a well selected palette, or the color will spread easily among consecutive pixels in the scan line of the image. This mode can display all of the 4,096 colors simultaneously.
This section needs expansion. You can help by adding to it. (May 2019) |
This section needs expansion. You can help by adding to it. (August 2024) |
Apple IIGS, along with full compatible graphic modes with the Apple II, features a custom Video Graphics Chip (VGC) [1] which supports a 12-bit RGB, 4,096-color palette. It has an extended set of 320×200 and 640×200 graphic modes, (called Super High-Res modes by Apple) with different (and a bit complex) color modes:
Also, along with the one of 16 palettes, to each scan line the Apple IIGS VGC is able to assign individual 320 or 640 horizontal resolution independently. The closest output would be:
0x0 | 0x1 | 0x2 | 0x3 | 0x4 | 0x5 | 0x6 | 0x7 | 0x8 | 0x9 | 0xA | 0xB | 0xC | 0xD | 0xE | 0xF |
This section has multiple issues. Please help improve it or discuss these issues on the talk page . (Learn how and when to remove these messages)
|
The Sharp X68000, released in 1987, uses a 16-bit RGB palette. All 65,536 colors can be displayed simultaneously in resolutions up to 512x512, or 16 out of 65,536 colors at the highest resolution of 1024x1024. [2]
The Enhanced Graphics Adapter (EGA) supports all CGA modes and add three more: two 320×200 and 640×200 graphic modes, both with the full CGA 16-color palette (intended to be used with the same "digital RGB" CGA color monitor of 200 scan lines) and an extra 640×350 graphic mode with 16 colors chosen from a 6-bit RGB (64 colors) palette for what IBM then called an "analog RGB"[ citation needed ] type monitor. [3]
The word analog means here that the RGB signals can have more than the bare two possible levels 0 and 1; (as the so-called —by IBM— "digital RGB" CGA monitor type has) despite its name, colors are produced digitally, so there exist binary (quantized) steps for every primary RGB signal (two bits, four levels per primary, in this case). Thus, the EGA signal from the computer to this kind of monitor had two wires for each primary red, green and blue. IBM developed a true analog video interface later, for the more advanced MCGA and VGA display adapters and monitors (and earlier, for the Professional Graphics Controller, announced simultaneously with the EGA) which are unrelated to (and incompatible with) the EGA "analog" monitors; see the next section.
Some early EGA cards shipped with only 64 KB of video memory—the nominal was 128 KB, up to a maximum of 256 KB to allow more screen pages in memory. With only 64 KB, the EGA 640×350 graphic mode provides only four colors. 4-color 640×350 graphics was never a proper mode by itself (merely a conditional downgrade of the 640×350 16-color mode) and therefore was not popular.
Monochrome "analog" monitors also existed for EGA. The colors are then mapped internally to the correspondent luminance gray, (the sum of the 30% of the red signal, the 59% of the green and the 11% of the blue) giving a 16-shades from a 64-grayscale palette. "Positive" class monitors inverts the signal, providing that the default EGA colors for text modes (black background and white foreground) displays reversed, (white background and black foreground) as if were a printed document.
16-color CGA | 16-color EGA | EGA on monochrome monitor | EGA palette |
0x00 | 0x01 | 0x02 | 0x03 | 0x04 | 0x05 | 0x06 | 0x07 |
0x08 | 0x09 | 0x0A | 0x0B | 0x0C | 0x0D | 0x0E | 0x0F |
0x10 | 0x11 | 0x12 | 0x13 | 0x14 | 0x15 | 0x16 | 0x17 |
0x18 | 0x19 | 0x1A | 0x1B | 0x1C | 0x1D | 0x1E | 0x1F |
0x20 | 0x21 | 0x22 | 0x23 | 0x24 | 0x25 | 0x26 | 0x27 |
0x28 | 0x29 | 0x2A | 0x2B | 0x2C | 0x2D | 0x2E | 0x2F |
0x30 | 0x31 | 0x32 | 0x33 | 0x34 | 0x35 | 0x36 | 0x37 |
0x38 | 0x39 | 0x3A | 0x3B | 0x3C | 0x3D | 0x3E | 0x3F |
Note: The colors underlined exist in the CGA palette; as well as it is used as default 16-color EGA color palette.
The Professional Graphics Controller used a 12-bit RGB palette (4096 colors), from which 256 could be displayed. Targeted at the CAD market this mode has limited software support, although some clone boards exist.
The Multi-Color Graphics Array (MCGA) and Video Graphics Array (VGA) used a 6-bits per channel, 64 level digital-to-analog converter to give an 18-bit RGB palette (262,144 colors), from which can be selected any 2, 16, or 256 at a time. [3] They both provided full compatibility with CGA modes, while VGA included all the EGA modes as well as the MCGA modes. When connected to analog monochrome monitors, they offered 64 levels of grey. Some of the first portable PCs featured a flat monochrome plasma display with a VGA in shades of red.
The 8514/A uses the 18-bit RGB palette from which the user could select any 256 at a time in both 640×480 and 1024×768 graphic modes. It does not support compatibility with VGA modes, but a VGA card is usually already installed and bridged to the 8514/A to provide a single output cable for a single monitor which can display any of all VGA and 8514/A possible modes.
The Extended Graphics Array (XGA) supports all 8514/A modes plus an 800×600 16-bit RGB Highcolor mode, with 65,536 simultaneous colors on screen.
Enhanced clones of the IBM VGA, known as Super VGA, (SVGA) support 256 simultaneous colors in 640×480 and higher pixel resolutions (800×600, 1024×768) in both 16 and 256 picked colors from the VGA 18-bit RGB palette, depending on the model and the manufacturer. Also, some SVGA cards support 15- and 16-bit RGB Highcolor modes, with 32,768 or 65,536 simultaneous colors on screen in 640×480 and higher resolutions. Some later models reach the 24-bit RGB true-color modes.
In the 1990s, most manufacturers adhered to the VESA BIOS Extensions (VBE), used for enabling standard support for advanced video modes (at high resolutions and color depths).
They are the direct predecessors, not the IBM 8514/A nor XGA, of actual graphic display PC hardware.
This section needs expansion. You can help by adding to it. (April 2019) |
This section has multiple issues. Please help improve it or discuss these issues on the talk page . (Learn how and when to remove these messages)
|
See Super VGA above
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 IBM PC compatible industry within three years. The term can now refer to the computer display standard, the 15-pin D-subminiature VGA connector, or the 640 × 480 resolution characteristic of the VGA hardware.
The Hercules Graphics Card (HGC) is a computer graphics controller formerly made by Hercules Computer Technology, Inc. that combines IBM's text-only MDA display standard with a bitmapped graphics mode, also offering a parallel printer port. This allows the HGC to offer both high-quality text and graphics from a single card.
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 addition to the original EGA card manufactured by IBM, many compatible third-party cards were manufactured, and EGA graphics modes continued to be supported by VGA and later standards.
The Apple IIGS is a 16-bit personal computer produced by Apple Computer. It is the fifth and most powerful of the Apple II family. It is compatible with earlier Apple II models, but has a Macintosh look and feel, and resolution and color similar to the Amiga and Atari ST. The "GS" in the name stands for "Graphics and Sound", referring to its enhanced multimedia hardware, especially its state-of-the-art audio.
Color depth or colour depth, 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 to a pixel, the concept can be defined as bits per pixel (bpp). When referring to a color component, the concept can be defined as bits per component, bits per channel, bits per color, and also bits per pixel component, bits per color channel or bits per sample (bps). Modern standards tend to use bits per component, but historical lower-depth systems used bits per pixel more often.
Mode 13h is the standard 256-color mode on VGA graphics hardware introduced in 1987 with the IBM PS/2. It has a resolution of 320 × 200 pixels. It was used in computer games and art/animation software of the late 1980s and early to mid-1990s. "13h" refers to the number of the mode in the VGA BIOS. The "h" stands for hexadecimal.
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 display standard.
The Multi-Color Graphics Array or MCGA is a video subsystem built into the motherboard of the IBM PS/2 Model 30, introduced in April 1987, and Model 25, introduced later in August 1987; no standalone MCGA cards were ever made.
The Monochrome Display Adapter is IBM's standard video display card and computer display standard for the IBM PC introduced in 1981. The MDA does not have any pixel-addressable graphics modes, only a single monochrome text mode which can display 80 columns by 25 lines of high-resolution text characters or symbols useful for drawing forms.
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 of which contains one of the characters of a character set; at the same time, contrasted to graphics mode or other kinds of computer graphics modes.
Hold-And-Modify, usually abbreviated as HAM, is a display mode of the 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 otherwise be possible. HAM mode was commonly used to display digitized photographs or video frames, bitmap art and occasionally animation. At the time of the Amiga's launch in 1985, this near-photorealistic display was unprecedented for a home computer and it was widely used to demonstrate the Amiga's graphical capability. However, HAM has significant technical limitations which prevent it from being used as a general purpose display mode.
Professional Graphics Controller is a graphics card manufactured by IBM for PCs. It consists of three interconnected PCBs, and contains its own processor and memory. The PGC was, at the time of its release, the most advanced graphics card for the IBM XT and aimed for tasks such as CAD.
The Plantronics Colorplus is a graphics card for IBM PC computers, first sold in 1982. It implements a superset of the then-current CGA standard, using the same monitor standard and providing the same pixel resolutions. It was produced by Frederick Electronics, a subsidiary of Plantronics since 1968, and sold by Plantronics' Enhanced Graphics Products division.
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 compression.
The eXtended Graphics Array is a graphics card manufactured by IBM and introduced for the IBM PS/2 line of personal computers in 1990 as a successor to the 8514/A. It supports, among other modes, a display resolution of 1024 × 768 pixels with 256 colors at 43.5 Hz (interlaced), or 640 × 480 at 60 Hz (non-interlaced) with up to 65,536 colors. The XGA-2 added an 800 × 600 65,536 color mode and 1024 × 768 60 Hz non-interlaced.
VGA text mode was introduced in 1987 by IBM as part of the VGA standard for its IBM PS/2 computers. Its use on IBM PC compatibles was widespread through the 1990s and persists today for some applications on modern computers. The main features of VGA text mode are colored characters and their background, blinking, various shapes of the cursor, and loadable fonts. The Linux console traditionally uses hardware VGA text modes, and the Win32 console environment has an ability to switch the screen to text mode for some text window sizes.
Tandy Graphics Adapter 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.
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 encoding allowed for extra colors to be displayed, by manipulating the pixel position on screen, not being limited by each machine's hardware color palette.