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Enhanced Graphics Adapter ( EGA ) is an IBM PC graphics adapter and de facto computer display standard from 1984 that superseded the CGA standard introduced with the original IBM PC , and was itself superseded by the VGA standard in 1987.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.
41-550: (Redirected from DE-15 ) DE.15 , DE-15 , DE 15 , DE15 or variant, may refer to: DE-15, a D-subminiature connector type VGA connector , the common application of the DE-15 connector DE.15, a Nickel–Strunz classification USS Austin (DE-15) Delaware Route 15 DE 15, one of the postcodes for Burton upon Trent DE15, an OECD region, see List of OECD regions by GDP (PPP) per capita JNR Class DE15 ,
82-1019: A Display Data Channel (DDC). The same VGA cable can be used with a variety of supported VGA resolutions, ranging from 320×400px @70 Hz, or 320×480px @60 Hz (12.6 MHz of signal bandwidth ) to 1280×1024px ( SXGA ) @85 Hz (160 MHz) and up to 2048×1536px ( QXGA ) @85 Hz (388 MHz). There are no standards defining the quality required for each resolution, but higher-quality cables typically contain coaxial wiring and insulation that make them thicker. While shorter VGA cables are less likely to introduce significant signal degradation, good-quality cable should not suffer from signal crosstalk (whereby signals in one wire induce unwanted currents in adjacent wires) even at greater lengths. Ghosting occurs when impedance mismatches cause signals to be reflected. A correctly impedance matched cable (75 ohm) should prevent this, however, ghosting with long cables may be caused by equipment with incorrect signal termination or by passive cable splitters rather than
123-413: A dual-sync design which could switch from the 15.7 kHz of 200-line modes to 21.8 kHz for 350-line modes. Many EGA cards have DIP switches on the back of the card to select the monitor type. If CGA is selected, the card will operate in 200-line mode and use 8×8 characters in text mode . If EGA is selected, the card will operate in 350-line mode and use 8×14 text. Some third-party cards using
164-583: A Japanese diesel locomotive type See also [ edit ] DD-15 (disambiguation) [REDACTED] Topics referred to by the same term This disambiguation page lists articles associated with the same title formed as a letter–number combination. If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=DE15&oldid=761015798 " Category : Letter–number combination disambiguation pages Hidden categories: Short description
205-479: A color from the EGA palette, two bits are used for the red, green and blue channels to signal values of 0, 1, 2 or 3. For instance, to select the color magenta, the red and blue values would be medium intensity (2, or 10 in binary) and the green value would be off (0). The table below displays an example palette matching the standard 16 CGA colors, with their representations in rgbRGB binary (internal card bit order), where
246-404: A display of up to 16 colors (using a fixed palette , or one selected from a gamut of 64 colors (6-bit RGB) , depending on mode) at several resolutions up to 640 × 350 pixels, as well as two monochrome modes at higher resolutions. EGA cards include a ROM to extend the system BIOS for additional graphics functions, and a custom CRT controller (CRTC) . The IBM EGA CRTC supports all of
287-587: A half dozen companies had announced EGA-compatible boards based on C&T's chipset. The first EGA-compatible board was Vega in December 1985, released by Video Seven and using C&T's chipset. The Vega was half the width of the original IBM EGA board. Between 1984 and 1987, several third-party manufacturers produced compatible cards, such as the Autoswitch EGA or Genoa Systems ' Super EGA chipset. Later cards supporting an extended version of
328-590: A minimum of 64 KB additional RAM, and up to 192 KB if fully populated with the Graphics Memory Module Kit . Without these upgrades, the card would be limited to four colors in 640 × 350 mode. Output was via direct-drive RGB , as with the CGA, but no composite video output was included. MDA and CGA monitors could be driven, as well as newly released enhanced color monitors for use specifically with EGA. EGA-specific monitors used
369-464: A variable blue tint due to the indeterminate state of the unconnected secondary blue. The IBM 5154 EGA monitor has a special IBM 5153 CGA compatibility mode when operating with CGA sync signals and automatically changes to the CGA pinout to avoid all of the mentioned problems when operating in this mode. The original IBM EGA card includes a feature connector (blue connector J4, see first photo on this page), providing access to two RCA connectors at
410-585: Is a notable example of a commercial game that runs in 640 × 350 with 16 colors mode. Modern adventure games, like The Crimson Diamond , use freeware tools like the Adventure Game Studio to create games with EGA-style color palettes but with modern features. The original IBM EGA was an 8-bit PC ISA card with 64 KB of onboard RAM . An optional daughter-board (the Graphics Memory Expansion Card ) provided
451-548: Is a three-row, 15-pin D-subminiature connector referred to variously as DE-15, HD-15 or commonly DB-15(HD). DE-15 is the accurate nomenclature under the propriotory D-sub specifications: an "E" size D-sub connector, with 15 pins in three rows. The standard 15-pin VGA connector was derived from the earlier DE-9 connector, which used the same "E" D-shell size (hence that connector's misnomer of DB-9 transferred its "DB" part to
SECTION 10
#1732771896870492-486: Is an electronic device that increases the signal strength from a VGA port, most often from a computer. They are often used in schools, businesses, and homes when multiple monitors are being run off one VGA port, or if the cable between the monitor and the computer will be excessively long (often pictures appear blurry or have minor artifacts if the cable runs too far without an extender). VGA extenders are sometimes called VGA boosters. Enhanced Graphics Adapter EGA
533-501: Is backward-compatible with CGA, allowing EGA monitors to be used on CGA cards and conversely. When operating in EGA modes, pins 2, 6 and 7 are repurposed for EGA's secondary RGB signals (see pinout table below). When operating in 200-line CGA modes, the EGA card is fully backward compatible with a standard IBM CGA monitor; however, third-party monitors had varying compatibility. Third-party monitors sometimes connected pin two to ground internally. When connected to an EGA card, this shorts
574-819: Is different from Wikidata All article disambiguation pages All disambiguation pages VGA connector The Video Graphics Array ( VGA ) connector is a standard connector used for computer video output. Originating with the 1987 IBM PS/2 and its VGA graphics system, the 15-pin connector went on to become ubiquitous on PCs, as well as many monitors, projectors and HD television sets. Other connectors have been used to carry VGA-compatible signals, such as mini-VGA or BNC , but " VGA connector " typically refers to this design. Devices continue to be manufactured with VGA connectors, although newer digital interfaces such as DVI , HDMI and DisplayPort are increasingly displacing VGA, and many modern computers and other devices do not include it. The VGA connector
615-519: Is divided into four "planes" (except 640 × 350 × 2, which has one plane), one for each component of the RGBI color space. Each pixel is represented by one bit in each plane. If a bit in the red plane is on, but none of the equivalent bits in the other pages are, a red pixel will appear in that location on screen. If all the other bits for that particular pixel were also on, it would become white, and so forth. Planes are different sizes depending on
656-527: Is not possible because those connectors don't output analog signals. For conversions to and from digital formats like HDMI or Displayport, a scan converter is required. VGA outputs to interfaces with different signaling, more complex converters may be used. Most of them need an external power source to operate and are inherently lossy . However, many modern displays are still made with multiple inputs including VGA, in which case adapters are not necessary. VGA can also be adapted to SCART in some cases, because
697-448: Is possible within the 15-pin interconnect. BNC prevents crosstalk by maintaining full coaxial shielding through the circular connectors, but the connectors are very large and bulky. The requirement to press and turn the plug shell to disconnect requires access space around each connector to allow grasping of each BNC plug shell. Supplementary signals such as DDC are typically not supported with BNC. Some laptops and other portable devices in
738-423: The 640 × 350 high-resolution mode, which requires an enhanced EGA monitor, 16 colors can be selected from a palette comprising all combinations of two bits per pixel for red, green and blue. This is four levels of intensity for each primary color and 64 colors overall. The 640 × 200 and 320 × 200 graphics modes provide backward compatibility with CGA software and monitors, but they can use
779-479: The CGA pin assignment in 200-line modes, so the monitor can also be used with a CGA card. Some EGA monitors are switchable , meaning that they can be set up to use the full palette even in 200-line modes, often through a mechanical switch. Only a few commercial games were released with support for the extended color palette in 320 × 200 or 640 × 200 (including the DOS version of Super Off Road ). When selecting
820-448: The DDC spec. Devices that comply with the DDC host system standard provide 5 V ± 5% , from 50 mA to 1 A. The IBM PS/55 Display Adapter redefined pin 9 as "+12V", which signals the monitor to turn on when the system unit is powered on. In order to advertise display capabilities VESA has introduced a scheme to redefining VGA connector pins 9, 12, and 15 as a serial bus for
861-548: The EGA specification were sold with the full 128 KB of RAM from the factory, while others included as much as 256 KB to enable multiple graphics pages, multiple text-mode character sets , and large scrolling displays. A few third-party cards, such as the ATI Technologies EGA Wonder , built on the EGA standard to additionally offer features such as extended graphics modes as high as 800 × 560 and automatic monitor type detection. EGA produces
SECTION 20
#1732771896870902-483: The EGA's secondary red output to ground and can damage the card. Also, some monitors were wired with pin two as their sole ground, and these will not work with the EGA. Conversely, an EGA monitor should work with a CGA adapter, but if it is not set to CGA mode, the secondary red signal will be grounded (always zero), and the secondary blue will be floating (unconnected), causing all high-intensity colors except brown to display incorrectly, and all colors to potentially have
943-450: The EGA, all 16 CGA colors can be used simultaneously, and each can be mapped in from a larger palette of 64 colors (two bits each for red, green and blue). The CGA's alternate brown color is included in the larger palette, so it can be used without any additional display hardware. The later VGA standard built on this by mapping each of the 64 colors in from a larger, customizable, palette of 256. Standard EGA monitors do not support use of
984-496: The EGA, the video memory begins at address A0000h and occupies 64 KB. The different base addresses for color vs. monochrome modes makes it possible for an EGA to be used simultaneously with a monochrome graphics card in the same computer, or for an EGA in MDA text mode to be used simultaneously with a CGA in the same computer. EGA's native graphics modes are planar , as opposed to the interleaved CGA and Hercules modes. Video memory
1025-532: The VGA were similarly named Super VGA . The EGA standard was made obsolete in 1987 by the introduction of MCGA and VGA with the PS/2 computer line. Commercial software began supporting EGA soon after its introduction, with The Ancient Art of War , released in 1984. Microsoft Flight Simulator v2.12 , Jet , Silent Service , and Cyrus , all released in 1985, offered EGA support, along with Windows 1.0 . Sierra's King's Quest III , released in 1986,
1066-437: The ability to connect or disconnect the output device during operation, although in practice this can be done and usually does not cause damage to the hardware or other problems. The VESA DDC specification does, however, include a standard for hot-swapping. In the original IBM VGA implementation, refresh rates were limited to two vertical (60 and 70 Hz) and three horizontal frequencies, all of which were communicated to
1107-477: The back of card, in addition to several analog and digital signals that the EGA adaptor can be configured to use. A light pen interface was also present on the original card. For color text and CGA graphics modes, video memory is mapped to 16 KB of addresses beginning at address B8000h, and in monochrome (MDA-compatible) text mode, video memory occupies 16 KB beginning at B0000h. These address mappings are for backward compatibility. For modes new to
1148-454: The cables themselves. Some high-end monitors and video cards used multiple BNC connectors instead of a single standard VGA connector, providing a higher quality connection with less crosstalk by utilising five separate 75 ohm coaxial cables . The use of BNC RGB video cables predates VGA in other markets and industries. Within a 15-pin connector, the red, green, and blue signals (pins 1, 2, 3) cannot be shielded from each other, so crosstalk
1189-445: The early to mid-2000s contained a two-row mini-VGA connector that is much smaller than the three-row DE-15 connector, as well as five separate BNC connectors. Various adapters can be purchased to convert VGA to other connector types. One common variety is a DVI to VGA adapter, which is possible because many DVI interfaces also carry VGA-compatible analog signals . Adapting from HDMI or DisplayPort to VGA without an active converter
1230-457: The early variant to relative obscurity. All VGA connectors carry analog RGBHV (red, green, blue, horizontal sync , vertical sync ) video signals. Modern connectors also include VESA DDC pins, for identifying attached display devices. In both its modern and original variants, VGA utilizes multiple scan rates , so attached devices such as monitors are multisync by necessity. The VGA interface includes no affordances for hot swapping ,
1271-478: The entire sixteen-color CGA palette simultaneously, instead of the smaller four-color palettes that the actual CGA is limited to in those modes. EGA's 16-color graphic modes use bit planes and mask registers together with CPU bitwise operations for accelerated graphics . The same techniques went on to be used in the VGA . EGA supports: Text modes: Extended graphics modes of third-party boards: With
DE15 - Misplaced Pages Continue
1312-490: The extended color palette in 200-line modes, because the monitor cannot distinguish between being connected to a CGA card or being connected to an EGA card outputting a 200-line mode. EGA redefines some pins of the connector to carry the extended color information. If the monitor were connected to a CGA card, these pins would not carry valid color information, and the screen might be garbled if the monitor were to interpret them as such. For this reason, standard EGA monitors will use
1353-466: The lowercase letters are the low-intensity bits, and uppercase letters are high-intensity bits. Decimal and hexadecimal values (converted to equivalent 24-bit sRGB web colors ) are also shown. The following images illustrate the full EGA palette in detail. EGA uses a female nine-pin D-subminiature ( DE-9 ) connector for output, identical to the CGA connector. The signal standard and pinout
1394-458: The mode: All planes reside at segment A000 in the CPU's address space. They are bank-switched, and only one plane can be read on the CPU bus at once; however, the programmer may set the control registers on the card to select which planes are written to and write to several at once. An exception is read mode 1, in which all four planes are read and compared with programmed "Color Compare" data, and
1435-736: The modes of the IBM MDA and CGA adapters through specific mode options, but it is not fully register-compatible with the Motorola MC6845 used in those cards, so software that directly programs the registers to select modes may produce different results on the EGA. Supported resolutions are 320 × 200 and 640 × 200 (on a CGA or EGA monitor ), 720 × 350 and 640 × 350 (on an MDA monitor) and 320 × 350 and 640 × 350 (on an EGA monitor). EGA scans at 21.8 kHz when 350-line modes are used and 15.7 kHz when 200-line modes are used. In
1476-465: The monitor using combinations of different polarity H and V sync signals. Some pins on the connector were also different: pin 9 was keyed by plugging the female connector hole, and four pins carried the monitor ID. With the implementation of the VESA DDC specification, several of the monitor ID pins were reassigned for use by DDC signaling, and the key pin was replaced with a +5 V DC output per
1517-451: The new DE-15 connector as well, see above). Though IBM always used DE-15 connectors for their Video Graphics Array hardware, several VGA clone hardware makers initially did not. Instead, some early VGA hardware, both monitors and VGA cards, used a DE-9 connector for VGA, just like what had been in use for MDA , CGA , Hercules , and EGA . This 9-pin variant of the then-emerging de-facto standard 15-pin connector omitted several pins, which
1558-546: The signals are electrically compatible if the correct sync rates are set by the host PC. Many modern graphics adapters can modify their signal in software, including refresh rate, sync length, polarity and number of blank lines. Particular issues include interlace support and the use of the resolution 720×576 in PAL countries . Under these restrictive conditions, a simple circuit to combine the VGA separate synchronization signals into SCART composite sync may suffice. A VGA extender
1599-426: Was considered acceptable, because the autodetection features supported by those pins only evolved over time, and prior to Windows 95 , there was no user expectation of graphics cards and displays being fully plug and play . DE-9 VGA connectors were generally compatible with each other, and adaptors to the DE-15 standard were available. Ultimately all VGA hardware makers switched to standard DE-15 connectors, relegating
1640-536: Was introduced in October 1984 by IBM, shortly after its new PC/AT . The EGA could be installed in previously released IBM PCs, but required a ROM upgrade on the mainboard . Chips and Technologies ' first product, announced in September 1985, was a four-chip EGA chipset that handled the functions of 19 of IBM's proprietary chips on the original Enhanced Graphics Adapter. By that November's COMDEX , more than
1681-440: Was one of the earliest mainstream PC games to use it. By 1987, EGA support was commonplace. Most software made up to 1991 could run in EGA, although the vast majority of commercial games used 320 × 200 with 16 colors for backward compatibility with CGA and Tandy , and to support users who did not own an enhanced EGA monitor. 350-line modes were mostly used by freeware/shareware games and application software, although SimCity