Video Standards at MonitorWorld.com informational interchange for monitors, adapters, and video cards

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Summary of Video Standards
MDA(Hercules) Monochrome Display Adapter MDA was the original display adapter on the IBM PC. Technically, it was a character-mapped system, meaning it was capable only of 256 special characters in set positions on the screen. It is not capable of pixel-by-pixel control, therefore no graphics can be shown with it. The only plus points of this system was the high resolution. It was ideal for simple DOS based applications with no graphics, like word processing. As a plus, IBM included an integrated printer port, thereby saving another slot. MDA Pinout: Pin 1 - Ground Pin 2 - Ground Pin 3 - Not Used Pin 4 - Not Used Pin 5 - Not Used Pin 6 - Intensity Pin 7 - Mono Video Pin 8 - Horizontal Sync Pin 9 - Vertical Sync CGA Color Graphics Adapter Videotype: TTL, 16 colors. AKA: IBM RGBI A few months after the release of the MDA, the CGA adapter came out. It worked with an RGB monitor and worked off the text-mapped method, meaning it was capable of the pixel-by-pixel control needed for graphics. It could also do 16 colors, 4 at a time, on a 320 x 200 display. The pixels are quite large and the resolution was bad, but it could do graphics. CGA offered a high-resolution mode of 640 x 200, but then it could only do two colors. Besides its limitations, this card remained very common for quite a while. It had a couple annoyances, which were flicker and snow. By snow, I mean one would sometimes get random dots on the screen. CGA uses a digital signal, referred to as TTL (Transistor-transistor Logic), for the transmission of its video signal. TTL is a signal that operates on a on or off state only, thus limiting the amount of displayable colors. Intensity bits are used to expand available colors up to four times the original amount. Commonly used in low resolution computers. CGA Pinout 640x200, 15.7kHz, 60Hz Pin 1 - Ground Pin 2 - Ground Pin 3 - Red Pin 4 - Green Pin 5 - Blue Pin 6 - Green Intensity Pin 7 - Blue Intensity Pin 8 - Horizontal Sync Pin 9 - Vertical Sync EGA Enhanced Graphics Adapter Videotype: TTL, 16/64 colors. CGA/EGA uses a digital signal, referred to as TTL (Transistor-transistor Logic), for the transmission of it's video signal. TTL is a signal that operates on a on or off state only, thus limiting the amount of displayable colors. Intensity bits are sued to expand available colors up to four times the original amount. Commonly used in low resolution computers. The Enhanced Graphics Adapter was next in the line. It stands between the CGA and the good old VGA cards. It was introduced in 1984 and was continued until 1987, when the first IBM PS/2 systems were set to market. It was a nice graphics card at the time, but it couldn't deliver the vast array of colors we all like today, so it is thus forgotten. It could produce 64 colors, but displayed only 16 of them at one time when used with an EGA monitor. It had a high-resolution mode and a monochrome mode, and was compatible with all previous monitors, including CGA and monochrome. One new feature on the EGA adapter was the memory expansion board. The EGA card came standard with only 64K of memory. With a memory expansion card, you got an extra 64K, for a total of 128K. Then, with the addition of a special IBM memory module kit, you could add another 128K, for a total of 256K of graphics memory. One good thing, though, was that most "after market" EGA cards came equipped with the full 256K of memory. EGA Pinout: 640 x 350, 15.7/21.8kHz, 60Hz Pin 1 - Ground Pin 2 - Red Intensity Pin 3 - Red Pin 4 - Green Pin 5 - Blue Pin 6 - Green Intensity Pin 7 - Blue Intensity Pin 8 - Horizontal Sync Pin 9 - Vertical Sync ECL (Sun and Apollo Monochrome) Pin 1 - ECL Video Pin 2 - ECL Video Return Pin 3 - Horizontal Sync Pin 4 - Vertical Sync Pin 5 - 5 Volts Pin 6 - ECL Video Pin 7 - ECL Video Return Pin 8 - Sync Return Pin 9 - 5V Return (Apple) Mac II/Quadra 640x480 to 1152x870 35-68kHz, 66.7-70Hz Use of analog video signals allows for unlimited colors to be produced. Macintosh graphic cards are unique in a couple of different regards. First, the variety of sync formats. In the past, sync has been available three different ways, and in some cases all from on card. Those formats are RGsB, RGBS, and RGBHV. Macintosh graphic cars also offer multiple lines rates and resolutions. These rates are resolutions are determined at boot up by the manner in which the sense lines (ID Bits) are terminated within the local monitor. Signal Type: Analog DB-15 Pinout: Pin 1 - Red Ground Pin 2 - Red Pin 3 - Composite Sync Pin 4 - Sense 0 Pin 5 - Green Pin 6 - Green Ground Pin 7 - Sense 1 Pin 8 - N/C Pin 9 - Blue Pin 10 - Sense 2 Pin 11 - C/V Ground Pin 12 - Vertical Sync Pin 13 - Blue Ground Pin 14 - Horizontal Ground Pin 15 - Horizontal Sync Apple II - 560x192 15.7kHz, 60Hz Mac 12" - 512x384 24.5kHz, 60Hz Mac 13" - 640x480 35.0kHz, 60Hz Mac 14" - 640x480 35.0kHz, 67Hz E-Mac - 832x624 44.9kHz, 67Hz Super Mac - 1024x768 48.0kHz, 60Hz Radius - 1024x768 48.0kHz, 60Hz Mac 16" - 832x624 49.7kHz, 75Hz Mac 19" - 1024x768 60.2kHz, 75Hz Mac 21" - 1152x870 68.7kHz, 75Hz (IBM) XGA/XGA-2/Super VGA Extended Graphics Array 640x480 to 1600x1200 31.5 - 117kHz, 40 - 110Hz IBM developed XGA/XGA-2 to provide a means to offer higher frequencies and resolutions in the "VGA" domain. These standards utilize software and ID bit termination to achieve these changes. Signal Type : Analog Pin 1 - Red Pin 2 - Green Pin 3 - Blue Pin 4 - ID Bit Pin 5 - Self Test Pin 6 - Red Return Pin 7 - Green Return Pin 8 - Blue Return Pin 9 - No Pin Pin 10 - Ground Pin 11 - ID Bit Pin 12 - ID Bit Pin 13 - Horizontal Sync Pin 14 - Vertical Sync Pin 15 - ID Bit VGA/XGA 1 - 640x350 31.5 kHz, 70Hz VGA/XGA 2 - 640x400 31.5 kHz, 70Hz VGA/XGA 3 - 640x480 31.5 kHz, 60Hz VGA/XGA 4 - 1024x768 35.5kHz, 87/43 Hz (Interlaced) VGA/XGA 5 - 1024x768 57.0 kHz, 70Hz VGA/XGA 6 - 1024x768 61.1 kHz, 75.8Hz Custom VGA - Up to 1600x1200 31-117kHz, 60-110Hz Note: Many graphic card manufacturers offer super high resolution modes that are not necessarily a standard (like XGA or VESA). Thus, a customer running on of these standard modes can be displaying a graphics resolution up to 1600x1200 at 117kHz (horizontal). VGA 640x480 31.5kHz, 60/70Hz IBM developed VGA in 1987, as one of the first computer video types to use analog signals. The ability to display sharper images with high color depth is something that, even today, is being constantly expanded upon. The most commonly recognized resolution is 640x480, 31.5kHz with 16 displayable colors out of a color palette of 64. Super VGA and XGA offer many more rates and resolutions. Signal Type: Analog Pin 1 - Red Pin 2 - Green Pin 3 - Blue Pin 4 - ID Bit Pin 5 - N/C Pin 6 - Red Return Pin 7 - Green Return Pin 8 - Blue Return Pin 9 - No Pin Pin 10 - Ground Pin 11 - ID Bit Pin 12 - ID Bit Pin 13 - Horizontal Sync Pin 14 - Vertical Sync Pin 15 - ID Bit VESA VGA (DDC) VGA=Video Graphics Adapter or Video Graphics Array. VESA=Video Electronics Standards Association. DDC=Display Data Channel. 640x480 to 1600x1200 31.5-106kHz, 56-85Hz This standards committee was adopted in 1988 to create a better standard than IBM's VTGA version. So far, VESA has offered more variety in video resolutions and it is still adopting more standards each year. Signals type: analog. To date, VESA has adopted standards that range from standard BGA (at 640x480) to super high resolution graphics (1600x1200 at 106kHz). Most VESA graphics cards are capable of switching resolutions "on-the-fly" if you are using Windows 95. Pin 1 - Red Pin 2 - Green Pin 3 - Blue Pin 4 - ID Bit Pin 5 - N/C Pin 6 - Red Return Pin 7 - Green Return Pin 8 - Blue Return Pin 9 - No Pin Pin 10 - Ground Pin 11 - ID Bit Pin 12 - ID Bit Pin 13 - Horizontal Sync Pin 14 - Vertical Sync Pin 15 - N/C VESA Super VGA In an attempt to bring some order to the chaos of competing and incompatible Super VGA standards on the market, the Video Electronics Standards Association (VESA) has worked to establish new video interface standards. The intention of these standards is to once again provide a standardized application program interface between video hardware and application software. This would allow software developers to write their code to work with a single standard video model instead of having to write custom code to support the many different cards in use in the market today. Originally ignored by many vendors, VESA support is now becoming generally accepted as beneficial, and something that buyers look for when shopping for a video card. This is in part due to the growing number of programs (especially games) that require VESA SVGA compatibility in order to function at peak performance. The VESA SVGA standard is called the VESA BIOS Extension, sometimes abbreviated as VBE. There are actually more than one now, as more than one version of the standard exists. What's interesting about VBE is that it can be implemented in either hardware or software. Some video cards support a particular VBE standard in hardware. Those that do not can use a small memory-resident program--which is sometimes called a "VESA driver" even though it technically isn't a driver--that will provide VESA support for many cards that don't support VBE natively. This flexibility has helped encourage the widespread adoption of the standard because even proprietary hardware can be made to work with standard software, mostly transparently. There are two common VBE standards currently in use: version 1.2 and version 2.0. Obviously, version 1.2 is seen much more in hardware than version 2.0 because it is older. Many newer cards provide native VBE 2.0 support. For those that do not, there are memory-resident programs such as SciTech's Display Doctor that can be used to provide VBE 2.0 support. For older cards, a program such as Display Doctor can actually improve performance because it controls the hardware more efficiently than the on-board BIOS does. Hardware support for VBE version 2.0 is preferable as this avoids the necessity of using a software program to provide VESA support. However, there are reports of some cards that have buggy implementations of VBE 2.0 that don't always work 100% correctly. In these cases supplementing with something like UniVBE can eliminate some of these problems. Pin 1 - Red Pin 2 - Green Pin 3 - Blue Pin 4 - ID Bit Pin 5 - N/C Pin 6 - Red Return Pin 7 - Green Return Pin 8 - Blue Return Pin 9 - No Pin Pin 10 - Ground Pin 11 - ID Bit Pin 12 - ID Bit Pin 13 - Horizontal Sync Pin 14 - Vertical Sync Pin 15 - N/C VESA Feature Connector 26 Pin Idc at the Video card. Pin 1 Pixel Data Bit 0 (PB) Pin 2 Pixel Data Bit 1 (PG) Pin 3 DAC Pixel Data Bit 2 (PR) Pin 4 DAC Pixel Data Bit 3 (PI) Pin 5 DAC Pixel Data Bit 4 (SB) Pin 6 DAC Pixel Data Bit 5 (SG) Pin 7 DAC Pixel Data Bit 6 (SR) Pin 8 DAC Pixel Data Bit 7 (SI) Pin 9 DAC Clock Pin 10 DAC Blanking Pin 11 Horizontal Sync Pin 12 Vertical Sync Pin 13 Ground Pin 14 Ground Pin 15 Ground Pin 16 Ground Pin 17 Select Internal Video Pin 18 Select Internal Sync Pin 19 Select Internal Dot Clock Pin 20 Not used Pin 21 Ground Pin 22 Ground Pin 23 Ground Pin 24 Ground Pin 25 Not used Pin 26 Not used 13W3 IBM PowerPC 640x480 to 1600x1200 31 - 61 kHz, 60 - 87Hz Some versions of the IBM PowerPC computer come equipped with a 13W3 video connector. This connector is utilized to maintain the signal integrity at the high frequencies at which this computer is capable of operating. Signal type: Analog Pin A1 - Red/Red Ground Pin A2 - Blue/Blue Ground Pin A3 - Green/Green Ground Pin 1 - ID Bit 2 Pin 2 - ID Bit 3 Pin 3 - Self Test Pin 4 - Digital Ground Pin 5 - Horizontal Sync Pin 6 - ID Bit 0 Pin 7 - ID Bit 1 Pin 8 - N/C Pin 9 - Vertical Sync Pin 10 - Digital Ground 13W3 Sun Color 1152x900 61 - 89 kHz, 60 - 80Hz Sun manufactures high end computers that are capable of very high resolutions. They are able to output these various resolutions from the same card, this is determined at boot up by the manner in which sense lines (ID Bits) are terminated within the local monitor. Signal Type: Analog Pin A1 - Red/Red Ground Pin A2 - Green/Green Ground Pin A3 - Blue/Blue Ground Pin 1 - N/C Pin 2 - N/C Pin 3 - Sense 2 Pin 4 - Sense Return Pin 5 - Composite Sync Pin 6 - N/C Pin 7 - N/C Pin 8 - Sense 1 Pin 9 - Sense 0 Pin 10 - Composite Sync Return Monitor Sense Bits Defined: Value Bit 2 Bit 1 Bit 0 Resolution 0 0 0 0 ? 1 0 0 1 Reserved 2 0 1 0 1280 x 1024 76Hz 3 0 1 1 1152 x 900 66Hz 4 1 0 0 1152 x 900 76Hz 19" 5 1 0 1 Reserved 6 1 1 0 1152 x 900 76Hz 16-17" 7 1 1 1 No monitor connected 13W3 SGI (Silicon Graphics) 1024 x 768 & 1280x1024 30-82kHz, 60-76Hz Silicon Graphics manufacturers high end computers that are sued in graphic rendering and CAD/CAM applications. This computer generally operated at two different frequencies (48kHz and 64kHz), which is determined upon boot up. This computer type outputs sync RsGsBs, RGsB, RGVS and RGBHV. Signal Type: Analog Pin A1 - Red/Red Ground Pin A2 - Green/Green Ground Pin A3 - Blue/Blue Ground Pin 1 - Monitor Type 3 Pin 2 - Monitor Type 0 Pin 3 - Composite Sync Pin 4 - Horizontal Drive Pin 5 - Vertical Drive Pin 6 - Monitor Type 1 Pin 7 - Monitor Type 2 Pin 8 - Digital Ground Pin 9 - Digital Ground Pin 10 - Sync 2 13W3 NeXT Color 1152x870 63.9kHz, 60Hz This computer type utilizes the 13W3 video connector to display high resolution graphics. The video output generally operates at 63kHz an is designed to work in conjunction with it's local monitor. Signal Type: Analog Pin A1 - Red/Red Ground Pin A2 - Blue/Blue Ground Pin A3 - Green/Green Ground Pin 1 - +12VDC Pin 2 - Power Switch Cont Pin 3 - Monitor Clock Pin 4 - Monitor Out Pin 5 - Monitor In Pin 6 - -12 VDC Pin 7 - Monitor Type 2 Pin 8 - Ground Pin 9 - Ground Pin 10 - Ground 13W3 Intergraph Signal type: Analog Pin A1 - Red/Red Ground Pin A2 - Green/Green Ground Pin A3 - Blue/Blue Ground Pin 1 - N/C Pin 2 - N/C Pin 3 - Monitor Sensing (2) Pin 4 - N/C Pin 5 - Composite Sync Pin 6 - N/C Pin 7 - N/C Pin 8 - Monitor Sensing (1) Pin 9 - N/C Pin 10 - Composite Sync Ground / Monitor Sensing (0) Used only with 2 MPIXEL Monitors (GT + Graphics Engine MSMT081) PGA In 1984, IBM introduced the Professional Graphics Array, or PGA. The name gives away its intended audience. This system, priced at almost $5,000, was intended for serious scientific or engineering applications. With a built on 8088 processor, it could perform 3D manipulation and animation at up to 60 frames per second. Besides the price, this system took up a total of three motherboard slots. Obviously, the cost precluded this system from ever taking on to the general public, and was later dropped for the VGA adapter. Video Type: Analogue Pin 1 - Red Pin 2 - Green Pin 3 - Blue Pin 4 - Composite Sync Pin 5 - Mode Control Pin 6 - Red Ground Pin 7 - Green Ground Pin 8 - Blue Ground Pin 9 - Ground VGA(9-Pin) VGA=Video Graphics Adapter or Video Graphics Array. Videotype: Analogue. Pin 1 - Red Pin 2 - Green Pin 3 - Blue Pin 4 - Horizontal Sync Pin 5 - Vertical Sync Pin 6 - Red Ground Pin 7 - Green Ground Pin 8 - Blue Ground Pin 9 - Sync Ground 8514/A 8514/A is a standard produced by IBM to work with its MCA bus. It works well, producing high resolutions on interlaced monitors. A later adaptation allowed fast refresh rates on noninterlaced monitors, producing high quality flicker free images. 8514/A works quite differently than a VGA, although they both use the same kind of monitor. On a 8514/A, the computer tells the video card what to do and the video card figures out how to do it. For example, it says "Draw a circle" and the card figures it out. These are higher level commands and are quite different than the pixel by pixel instructions which must be calculated by the CPU in standard VGA cards. This is called hardware acceleration. 8514/A cards are much faster than VGA cards and often provide higher quality images than the VGA card. Nevertheless, IBM discontinued this format in favor of the more advanced XGA. MCGA The multicolor Graphics Array is archaic hardware. It was integrated into the motherboards of old PS/2 models 25 and 30. When coupled with a proper IBM display, it supported all CGA modes, but it was not compatible with previous monitors. MCGA could muster 64 shades or gray, thereby giving it the ability to simulate color images on monochrome monitors.
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