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VIDEO ADAPTERS AND ACCELERATORS

1. MB Check the physical installation See that the video board is installed properly in its expansion slot and make sure that any video card jumpers are set properly for the particular host system M Check for memory conflicts The memory space used by video adapters is hotly contested territory in the upper memory area Printer drivers sound cards tape backups SCSI adapters and scanners are just some of the devices that can step all over the memory space needed by a video board Many of today s video boards require you to exclude arange of upper memory through your memory manager often AOOOh through C7FFh though your particular video board may be different Make sure that any necessary memory exclusions are made in CONFIG SYS at the memory manager s command line You may also have to add an EMMExclude A000 C7FF line to the 386enh section of your SYSTEM INI file M Suspect your memory manager Advanced real mode memory managers such as QEMM or Netroom use very aggressive techniques to find memory Often doing this interferes with video operation Try disabling any Stealth or Cloaking mode or try disabling your real mode memory man ager outright MB Check your system s CMOS setup Today s motherboards sport all manner of advanced features Try systematically disabling such attributes as video cache video RAM shadow byte merge palette snoop or decouple hidden refresh If PCI bus bursting is used on the video bus try d
2. older AGP motherboards often required this If so set the required jumper to that AGP is enabled 6 Remove the new video card from its bag and insert it into its appropriate bus slot Be sure that the card is seated evenly and completely then bolt the card s bracket to the chassis 7 Ifthere s another video 3D accelerator card in the system you may need to attach that accelera tor s feature connector to the new video card 8 Reattach power and restart the system 9 When the system boots for the first time be sure to boot directly to the CMOS Setup If you must dis able the old on board video adapter through the CMOS Setup you must do that now If you re install ing an AGP video adapter in place of a PCI model check to see if there are any AGP related settings needed to enable AGP support on the system Save your changes and exit the CMOS Setup INSTALLING THE NEW SOFTWARE Once the CMOS Setup has been updated and your changes if any have been saved the system will start to reboot At this point we ll see if the new video card is identified properly and install the appropriate drivers and support software to utilize its features VIDEO FEATURE CONNECTORS 1543 1 Allow the system to boot normally Since virtually all video cards are now PnP compliant Win dows 95 98 should identify the new video device and query you for the appropriate drivers typi cally provided on CD 2 Place the CD into the CD ROM drive
3. tricks the PC user into seeing a 3D image on a flat a 2D screen There has been an astonishing rise in the demand for 3D video from all parts of the PC industry 3D rendering has proven to be the technique of choice for many types of high end games business presentations computer aided design and multimedia applica tions However the use of 3D demands more of a PC than simply passing huge volumes of data across an expansion bus 3D rendering requires complex mathematical calculations determinations of coloring the inclusion of special effects and conversion of the rendered scene to a 2D plane the display and in many cases all this must be accomplished in real time 15 frames per second Today most video sys tems are upgraded for the express purpose of supporting 3D animation usually in 3D computer games such as Quake III This part of the chapter examines some of the key factors involved on 3D rendering and acceleration THE 3D PROCESS To display a 3D object in real time an object is first represented as a set of points or vertices in a 3D coor dinate system that is x y and z coordinates The vertices of the given object the object may be a car a fighter plane or a complete 3D world are stored in system RAM and completely define the object In order to display this object on the flat 2D monitor the object must be rendered Rendering is the act of calculating on a per pixel basis the different
4. A video driver is a rather small program that allows an operating system such as Windows 95 98 to access a video adapter s high resolution and high color video modes with little or no interaction from the system BIOS Video drivers have a profound effect on your video performance and stability and during troubleshooting it will be necessary for you to isolate display problems to either the monitor the video adapter or video driver before a solution can be found This chapter explains the operation and troubleshooting of typical 2D and 3D video adapters Understanding Conventional Video Adapters The conventional frame buffer is the oldest and most well established type of video adapter The term frame buffer refers to the adapter s operation image data is loaded and stored in video memory one frame at a time Frame buffer architecture as shown in Figure 43 2 has changed very little since PCs first started displaying text and graphics The heart of the frame buffer video adapter is the highly inte grated display controller IC sometimes called a CRTC or Cathode Ray Tube Controller The CRTC gen erates control signals and supervises adapter operation It is the CRTC that reads video RAM or VRAM 1516 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS contents and passes those contents along for further processing Many new video boards use specially designed IC groups called chipsets that are intended to work together Chipset
5. NV1 STG 2000 http www nvidia com 1526 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS TABLE 43 2 LISTING OF POPULAR 2D AND 3D VIDEO CHIPSETS CONTINUED MANUFACTURER PRODUCT NVidia Riva 128 NVidia Riva 128ZX NVidia Vanta NVidia Riva TNT and TNT2 NVidia Quadro NVidia GeForce 256 Number Nine Imagine 128 Series 2 http www nine com products index html Number Nine Ticket To Ride Number Nine Ticket To Ride IV Oak Technologies Inc OTI 057 67 http www oaktech com Oak Technologies Inc OTI 077 Oak Technologies Inc OTI 087 Oak Technologies Inc OTI 64105 107 Oak Technologies Inc OTI 64111 Oak Technologies Inc OTI 64217 Realtek Semiconductor Corp RTG31051 http www realtek com tw Rendition V rit http www rendition com S3 Inc Aurora64V http www s3 com S3 Inc S3 801 S3 Inc S3 805 805p S3 Inc S3 805l S3 Inc S3 864 Sac S3 868 S3 Inc S3 911 SSI S3 924 S3 Inc S3 928 San S3 964 S3 Inc S3 968 San S3 VIiRGE S3 Inc S3 VIiRGE VX SC Scenic MX2 S3 Inc Trio32 732 S3 Inc Trio64 764 S3 Inc Trio64UV S3 Inc Trio64V S3 Inc Savage3D S3 Inc Savage4 S3 Inc Savage2000 Sierra Semiconductor Falcon 64 Sierra Semiconductor SC15064 UNDERSTANDING GRAPHICS ACCELERATORS 1527 TABLE 43 2 LISTING OF POPULAR 2D AND 3D VIDEO CHIPSETS CONTINUED MANUFACTURER PRODUCT Silicon Integrated Systems Silicon Integrated Systems Sil
6. VGA BIOS Sequence AGP PCI PCI AGP PCI AGP Graphics aperture size Target 1 2 installed RAM Write Cache Pipeline disable Read Around Write disable Primary Frame Buffer disable TROUBLESHOOTING VIDEO ADAPTERS 1549 TABLE 43 8 TYPICAL BIOS SETTINGS FOR AN AGP CARD CONTINUED BIOS SETTINGS PCI AGP GENERAL VGA Frame Buffer disable Frame Buffer Posted Write disable RAS CAS Delay 3T Cache Read disable VIA Motherboards CPU Wait Pipeline disable VIA Motherboards AGP Master 1 WS Write enable disable AGP Master 1 WS Read enable disable AGP Ratio set to 2 3 instead of 1 1 AGP Multi Trans Timer disable AGP Low Priority Timer disable AGP 2x disable AGP Turbo Mode disable AGP Bus Turbo Mode disable AGP Transfer Mode 1x Must both be set the same enable disable Troubleshooting Video Adapters A PC video system consists of four parts the host PC itself the video adapter accelerator the monitor and the software video BIOS and drivers To deal with a failure in the video system you must be able to isolate the problem to one of these four areas When isolating the problem your best tool is a working or testbed PC With another PC you can systematically exchange hardware to verify each element of the video system The companion CD provides several tools that may help you analyze and tweak your video system Check out FastVid 1 10 FASTV110 ZIP Hz Tool 1 2
7. extremely reasonable prices If it were not for the lack of standardization in SVGA adapters VGA would likely be considered obsolete already The Video Electronics Standards Association VESA has started the push for SVGA standards by proposing and supporting the VESA BIOS Extension VBE a universal video driver The extension now at version 3 0 provides a uniform set of functions that allows applica tion programs to detect a card s capabilities and to use the optimum adapter configuration regardless of how the particular board s hardware is designed Virtually all of the SVGA boards in production today support the VESA BIOS Extensions and it is worthwhile to recommend boards that support VESA SVGA Some SVGA boards even incorporate the extensions into the video BIOS ROM which saves the RAM space that would otherwise be needed by a video driver 1522 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS XGA 1990 The XGA and XGA 2 are 32 bit high performance video adapters developed by IBM to support MicroChannel based PCs XGA design with MicroChannel architecture allows the adapter to take con trol of the system for rapid data transfers MDA CGA EGA and VGA modes are all supported for back ward compatibility In addition several color depths are available at 1024x768 resolution and a photo realistic 65 536 colors are available at 640x480 resolution To improve performance even further fast video RAM and a graphics co processor are adde
8. unlimited colors a VGA board can produce only 256 of those colors in any 256 color mode Older video boards stored the palette entries in registers but the large pal ette video modes now available 64K colors through 16 million colors require the use of RAM Boards that incorporate a RAMDAC Random Access Memory Digital to Analog Converter are preferred since accessing memory integrated with DACs tends to be much faster than accessing discrete RAM else where on the board Keep in mind that the RAM on a RAMDAC is used for holding palette informa tion not the actual image Expansion bus architectures Finally graphic data must be transferred between the PC mother board and the adapter as you saw early in this section Such transfer takes place across the PC s expansion bus If data can be transferred between the PC and adapter at a faster rate video performance should improve Consequently the choice of bus architecture has a significant impact on video performance Video accelerators are available to support four bus architectures ISA VL PCI and AGP ISA The venerable Industry Standard Architecture ISA has remained virtually unchanged since its introduction with the PC AT in the early 1980s The ISA continues to be a mature interface standard for most IBM compatible expansion devices The sheer volume of ISA systems currently in service guaran tees the ISA a place on desktops for at least another ten years However ISA s 16 bit
9. 43 VIDEO ADAPTERS AND ACCELERATORS EMM386 try disabling the memory manager in CONFIG SYS or boot the system from a clean floppy Try your diagnostic s again chances are that the problem has disappeared To fix this problem on a more permanent basis re enable the memory manager using an exclude command Try x B100h B1FFh as the first parameter on the memory manager s command line If that does not work try x A000h BFFFh Finally try x A000h C7FF The characters shown in the display appear fuzzy This is often the result of a speed problem where the system is running too fast for the VL bus video board In virtually all cases you will find the VL bus to be running over 33MHz Try slowing down the VL bus speed This will sacrifice video performance but should stabilize the system Chances are also very good that the system has been locking up frequently slowing down the video board should also correct such lock ups Pixels appear dropped behind the mouse cursor and graphic images appear to break up under Windows There are two major causes for this older type of problem bad video RAM or a system ISA bus speed that is too fast Check the CMOS Setup for an entry in Advanced Setup such as AT Bus Clock ISA Bus Speed or AT Bus Speed The corresponding entry should be set to 8 33MHz Otherwise excessive speed may be resulting in lost video data If the bus speed is set properly run a diagnostic to check the int
10. Graphics Array 1987 The Multi Color Graphics Array MCGA had originally been integrated into the motherboard of IBM s PS 2 25 and PS 2 30 MCGA supports all of the CGA video modes and also offers several new video modes including a 320x200x256 mode that had become a preferred mode for game software of the day MCGA was one of the first graphic systems to use analog color signals rather than TTL signals Analog signals were necessary to allow MCGA to produce its 256 colors using only three primary color lines red green and blue or RGB IBM also took the opportunity to employ a new high density 15 pin sub miniature D type connec tor as shown in Figure 43 6 One of the striking differences between the analog connector and older TTL connectors is the use of individual ground lines for each color Careful grounding is vital since any signal noise on the analog lines will result in color anomalies If you inspect a video cable closely you will find that one or both ends are terminated with a square metal box which actually contains a noise filter It is important to realize that although the MCGA could emulate CGA modes older TTL monitors were no longer compatible with analog RGB signal levels Although there were a number of notable technical improvements that went into the PS 2 design none of them could assure broad acceptance of the PS 2 series However the MCGA ushered in a new age of analog display technology and virtu
11. HZTOOL ZIP and WinTune 98 1 0 32 WT98_32 EXE ISOLATING THE PROBLEM AREA The first step is to verify the monitor by testing it on a known good working PC Keep in mind that the monitor must be compatible with the video adapter on which it is being tested If the monitor works on another PC the fault lies in one of the three remaining areas If the monitor fails on a known good machine try the known good monitor on the questionable machine If the known good monitor then works on your questionable machine you can be certain that the fault lies in your monitor and you can refer to the appropriate chapter here for detailed troubleshooting if you wish If the monitor checks out suspect the video adapter Follow the same process to check the video adapter Try the suspect video adapter on a known good PC If the problem follows the video adapter you can replace the video adapter If the suspect video adapter works in a known good system the adapter is probably good Replace the adapter in the suspect machine but try another expansion slot and make sure that the monitor cable is attached securely 1550 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS If both the monitor and the video adapter work in a known good PC but the video problem persists in the original machine suspect a problem with the PC motherboard Try the working video adapter in another expansion slot Either the expansion slot is faulty or a fault has occurred on the motherboar
12. Logic ALG 25128 Avance Logic ALG 2564 Avance Logic ALG 27000 Avance Logic ALG 2101 Avance Logic ALG 2228 Avance Logic ALG 2301 UNDERSTANDING GRAPHICS ACCELERATORS 1525 TABLE 43 2 LISTING OF POPULAR 2D AND 3D VIDEO CHIPSETS CONTINUED MANUFACTURER PRODUCT Chips and Technologies 64300 purchased by Intel Chips and Technologies 82c455 6 Chips and Technologies 82c452 Chromatic Research Mpact Cirrus Logic Inc CL GD5420 http www cirrus com Cirrus Logic Inc CL GD5421 Cirrus Logic Inc CL GD5422 Cirrus Logic Inc CL GD5424 Cirrus Logic Inc CL GD5425 Cirrus Logic Inc CL GD5426 Cirrus Logic Inc CL GD5428 Cirrus Logic Inc CL GD5429 Cirrus Logic Inc CL GD5430 Cirrus Logic Inc CL GD5434 Cirrus Logic Inc CL GD5434 E Cirrus Logic Inc CL GD5436 Cirrus Logic Inc CL GD5440 Cirrus Logic Inc CL GD5446 Cirrus Logic Inc CL GD5462 Cirrus Logic Inc CL GD54M40 Cirrus Logic Inc CL GD5480 IIT AGX AGX 015 IIT AGX AGX 016 Intel Corp Intel i740 http developer intel com design graphics Intel Corp Intel i810 integrated chipset AGP Lockheed Martin Matrox Matrox Matrox Matrox Matrox Matrox Matrox Matrox Matrox Matrox Matrox NCR NCR NVidia SGS THOMSON Real3D MGA 1064SG http www matrox com MGA 2064W Mystique 220 Millennium II m3D Productiva G100 Mystique G200 Marvel G200 Marvel G400 Millennium G200 Millennium G400 77C22E 77C32BLT
13. RAM is not so important to a video accelerator as the RAM s speed Faster memory is able to read and write image data faster so adapter performance is improved The introduction of specialized video RAM VRAM memory devices with two separate data busses that can be read from and written to simultaneously is reputed to be superior to conventional dynamic RAM DRAM or EDO RAM such as the kind used for ordinary PC memory Recent DRAMs have made speed advances that have narrowed that gap while still remaining very economical At this point adapters with fast DRAM or EDO RAM are just about as fast as adapters with special ized video RAM for video modes up to 1024x768x256 For higher modes and color depths found on high end accelerators specialized video RAM is still the way to go for optimum performance DDR SDRAM Double Data Rate SDRAM memory looks promising for both system and graphics memory It effectively doubles its speed by using both edges of each clock cycle Keep in mind that graph ics board manufacturers are using the doubled rate in their specifications and advertising AGP video boards are also being produced in different versions and prices depending on the type and speed of the memory provided on each adapter and AGP video adapters can also access system RAM for certain video data storage Video BIOS and drivers Software is often considered as an afterthought to adapter design yet it plays asurprisingly important role in acceler
14. Rendering as you saw above is the actual drawing of the object on the screen A typical graphics accelerator takes the load off of the CPU so that the CPU can devote more processing power to other functions More advanced CPUs such as the Pentium MMX Pentium II or Pentium II with SME technology incorporate additional instructions that aid many of the calculation intensive work needed in 3D environments Three features that most often effect 3D speed are bus mastering resolution and color depth Bus mastering With a PCI bus master graphics accelerator a 3D graphics engine will never incur latency delays during the rendering process because once the CPU has prepared all of the triangles for ren dering the bus master will come and fetch the list of triangles asynchronously without requiring the CPU to wait There are two different implementations of bus mastering the basic bus master and the scatter gather bus master A basic bus master is capable of operating independently from the host CPU for short periods of time before it interrupts the host to ask for direction During data intensive operations like 3D this approach minimizes the advantages of bus mastering By contrast a scatter gather bus master is able to operate almost independently from the host CPU achieving significant performance benefits Bus mastering is eliminated if graphics are implemented through AGP since AGP is essentially a point to point connection between the graphics
15. The disadvantage of GDI is that it was not designed for high performance graphics software It was made to be used by business applications like word pro cessors and spreadsheet applications The GDI provides access to a video buffer in system memory not video memory and does not take advantage of special features that some video cards provide As a result the traditional GDI is great for most types of business software but it is far too slow for multimedia or game software DirectDraw circumvents this limitation by providing drawing surfaces that represent actual video memory With DirectDraw an application can write directly to the memory on the video card making your graphics routines extremely fast Surfaces are represented as contiguous blocks of memory mak ing it easy to perform addressing within them DirectDraw also supports hardware accelerated func tions like bit blitting and overlays DirectDraw works with a wide variety of display hardware It is designed so that applications can determine the capabilities of the underlying display hardware and then use any supported hardware accelerated features Any features that are not supported in hardware can then be emulated in software In actual practice DirectDraw is not a high level graphics API that draws graphics primitives like lines and rectangles Instead DirectDraw is a low level API that operates at the graphics surface level providing the essential support for higher
16. a big part in Windows If your display problems are occurring in Windows make sure that you have loaded the proper video driver and that the driver is compatible with the video board being used If problems persist in Windows load the standard generic VGA driver The generic VGA driver should function properly with virtually every video board and VGA or SVGA monitor available If the problem disappears when using the generic driver setup the original driver is incorrect corrupt or obsolete Contact the driver manufacturer to obtain a copy of the latest driver version If the problem persists the video adapter board may be defective or incompatible with Windows Try another video adapter Your Viper II Z200 video card doesn t work on a VIA or ETEQ based system This is the same on both Super 7 and Slot 1 based systems The Viper II Z200 card does not interact properly with the MVP3 or ETEQ chipsets Check to see that the AGP driver and IRQ routing drivers have been installed properly before attempting to install the display adapter All the necessary motherboard updates can be found in a file from http www viatech com drivers 4IN1409 exe This patch is supposed to work for both the MVP3 and ETEQ chipset Super 7 as well as the VIA Apollo Pro chipset for Pentium II systems 1558 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS Your Viper V770 video card doesn t work on an ALI based system This is the same on both Super 7 and Slot 1 based s
17. adapter and core logic and the graphics adapter is always considered to be the master device 3D GRAPHICS ACCELERATOR ISSUES 1533 Resolution Because of limitations in operating systems and graphics accelerators most games and multimedia applications have been developed for low resolutions such as 320 x 200 to achieve high per formance Increasing resolution means displaying more pixels on the screen with every frame thereby placing more demand on the monitor and graphics board Some applications developed in 320 x 200 can be played at 640 x 400 but the extra pixels are simply a replication of existing ones making the image appear blocky With today s standards in software and fast hardware accelerators developers can include more unique pixel information in each frame effectively increasing graphics detail at resolutions as high as 800x600 or 1024x768 This technology allows gamers to play in high resolutions without any performance loss Color depth Using extra colors in 3D games makes the scenes much richer and more life like The more colors used in a scene the more detailed and realistic it looks but more calculations are needed to determine the color of each rendered pixel With the new generation of 3D graphics accelerators higher color depths are supported without dramatic performance loss and developers can now use more colors in each scene For example developers can now use 16 bit 65K or 24 bit 16 7M color i
18. as ground lines while the horizontal sync sig nal is produced on pin 8 and the vertical sync signal is produced on pin 9 CGA is strictly a digital display system with TTL signals used on the Red 3 Green 4 Blue 5 and Intensity 6 lines Ground Ground n a n a n a Intensity video Horizontal sync Vertical sync SO GO EN One CON 6 MDA 10 FIGURE 43 3 Pinout of an MDA video connector REVIEWING VIDEO DISPLAY HARDWARE 1519 Ground Ground Red Green Blue Intensity n a Horizontal sync Vertical sync HONOR CINE 6 CGA 10 FIGURE 43 4 Pinout of a CGA video connector EGA Enhanced Graphics Adapter 1984 It was not long before the limitations of CGA became painfully apparent The demand for higher resolu tions and color depths drove designers to introduce the next generation of video adapters known as the Enhanced Graphics Adapter One of the unique appeals of EGA was its backward compatibility an EGA board would emulate CGA and MDA modes on the proper monitor as well as its native resolutions and color depths when using an EGA monitor EGA is known for its 320x200x16 640x200x16 and 640x350x16 video modes More memory is needed for EGA and 128KB is common for EGA boards although many boards could be expanded to 256KB The EGA connector pinout is illustrated in Figure 43 5 TTL signals are used to provide Primary Red 3 Primary Green 4 and Primary Blue 5 color signals By addin
19. color and position informa tion that tricks the viewer into perceiving depth on the 2D screen Rendering also fills in the points on the surface of the object that were previously stored only as a set of vertices In this way a solid object even shaded with shadows and fog for 3D effect can be drawn on the screen In order to render an object it is necessary to determine the color and position information To accomplish this efficiently 1532 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS the vertices of the object are segmented into triangles and these triangles a set of three vertices are then passed down the 3D processing pipeline one at a time The actual steps are shown below M Triangularize the 3D object This process divides the 3D object into triangles sets of three vertices M Transformation Translates rotates and zooms the object as necessary on the basis of the camera angle This part of the rendering process is mathematically intensive M Clipping Eliminates any portions of the object that fall outside of the window of the viewer s line of sight Clipping also demands a fair amount of mathematical processing M Lighting Calculates shadow or light information depending on where light sources in the world are positioned Other effects such as fog can also be included E Map triangles to screen The triangularized transformed clipped and illuminated object must then be mapped t
20. data bus width its lack of such advanced features as interrupt sharing or bus mastering and its relatively slow 8 33MHz operating speed allow a serious bottleneck to form for the incredible volume of video data demanded by Windows 95 98 and most graphics intensive DOS applications ISA works but it is no longer the inter face of choice to achieve optimum video performance When recommending an accelerator product look to the newer busses for best results VL Bus By the early 1990s the Video Electronics Standards Association VESA had invested a great deal of time and effort to develop a standard bus interface which has been optimized for video oper ation In essence this video bus is local to the system CPU allowing faster access without the 8 33MHz limitation imposed by ISA The actual bus speed is limited by the system clock speed The VESA Local bus VL bus or VLB achieved a remarkable level of industry acceptance and success in boosting 1530 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS video performance especially when used with a high quality graphics accelerator board However the 32 bit VL bus is generally limited to video systems Other peripherals such as IDE hard drive controllers have been built for the VL bus but VL bus limitations frequently interfere with multiple VL cards in the same system especially with faster motherboards As a result existing VL compatible PCs typically offer only one or two VL
21. expansion slots the other expansion slots are ISA Video accelerators are no longer manufactured for the VL bus virtually all high performance video boards today are designed for the PCI or AGP busses PCI Intel s Peripheral Component Interconnect PCI bus was one of the newest and most exciting bus architectures to reach the PC The PCI bus runs at a fixed frequency of 30 or 33MHz and offers a full 64 bit data bus that can take advantage of new 64 bit CPUs such as Intel s Pentium though most imple mentations of the PCI bus are designed for a 32 bit implementation The PCI bus overcomes the speed and functional limitations of ISA and the PCI architecture is intended to support all types of PC peripher als not just video boards Current PCI video boards now clearly outperform ISA and VL bus type video adapters AGP Intel developed and introduced an advanced local bus architecture called AGP the Acceler ated Graphics Port a close cousin of PCI intended to meet the increasing demands for speed and band width needed to support real time 3D graphics AGP is a dedicated high speed bus that directly connects the chipset and the graphics controller This connection creates a data channel specifically for graphics unlike the PCI bus which must share bandwidth and system resources among the various PCI peripher als that are installed in any given system The introduction of AGP removes data hungry 3D and video data transfers f
22. flip of the page the animation would appear to flicker Double buffering requires having two areas reserved on the frame buffer of the 3D graphics card Both regions need to be the size of the visible screen and one buffer is used to render the next frame of the animation while the other displays the previously rendered animation frame on the monitor Under Win dows double buffering requires the use of bit blitting to copy the animation from buffer to buffer Color dithering The number of colors that can be drawn to the visible screen depends on the number of bits per pixel that carry color information For instance with 8 bits per pixel of color information only 256 1536 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS colors can exist on the desktop at any one time Color dithering is the process of mixing these defined colors into small patterns to produce a wider spectrum of color without requiring extra video memory This proce dure is especially important in 3D since techniques such as Gouraud shading require many shades of each color used in each scene If dithering were not handled in hardware a 3D scene could contain only eight dif ferent main colors in 256 color mode each color would require 32 shades to be programmed into the Color Look Up Table to roughly approximate Gouraud shading With hardware support for color dithering a scene with many more colors may be rendered without requiring extra video RAM Anti aliasing Th
23. glance it is actually more likely to be related to a buggy video driver Upgrade the video driver to the latest version or try a generic video driver a reference driver that is compatible with your video chipset The display colors change when exiting from a DOS shell under Windows This problem has been noted with older video boards such as the Diamond SpeedStar Pro and is almost always the result of a video board defect usually a palette problem For the Diamond board the product must be replaced with revision A2 For other video boards such problems can usually be cor rected by replacing the video board outright TROUBLESHOOTING VIDEO ADAPTERS 1565 The computer locks up or crashes when starting an AVI file This problem is encountered frequently as computer users first begin to try multimedia applications Rather than being a problem with the video board specifically the trouble is often due to using an outdated version of Video for Windows Make sure to use Video for Windows 1 1E or later Video for Windows can be downloaded from the Diamond Multimedia FTP site at ftp ftp diamondmm com pub misc vfwlle exe You may also need to edit the DrawDib section of the WIN INI file and add an entry that says DVA 0 If no DrawDib section is present you can add it Remember to restart Windows after making any changes You may also be able to correct this type of problem by upgrading to Windows 98 SE which should contain many of th
24. in a CONFIG SYS file Check the adapter s instruction manual to see if there are any memory configuration changes or optimizations that are required There is no display and you hear a series of beeps when the PC initializes The video adapter failed to initialize during the system s POST Since the video adapter is not responding it is impossible to display information that is why a series of beeps are used Bear in mind that the actual beep sequence may vary from system to system depending on the type of BIOS being used You can probably find the beep code for your BIOS in Chapter 19 In actual practice there may be several reasons why the video adapter fails Power down the PC and check that the video adapter is installed properly and securely in an expansion slot Make sure that the video adapter is not touching any exposed wiring or any other expansion board 1556 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS Isolate the video adapter by trying another adapter in the system If the display works properly with another adapter installed check the original adapter to see that all settings and jumpers are correct If the problem persists the original adapter is probably defective and should be replaced If a new adapter fails to resolve the problem there may be a fault elsewhere on the motherboard Install a POST board in the PC and allow the system to initialize Each step of the initialization procedure corresponds to a two digit hex ade
25. level 2D and 3D graphics APIs that do draw and render MORE ON DIRECTSOUND DirectSound is the audio component of DirectX DirectSound enables hardware and software sound mix ing capture and effects like 3D positioning and panning In operation DirectSound is essentially a sound mixing engine the application places a set of sounds in buffers called secondary buffers DirectSound then combines these sounds and writes them into a primary buffer that holds the sound that the listener 1538 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS actually hears DirectSound automatically creates a primary buffer which typically resides in memory on the sound card itself The application creates the secondary buffers either in system memory or directly on the sound card DirectSound supports pulse code modulation PCM sound data but does not currently support compressed wave formats DirectSound does not include functions for parsing a sound file it is the responsibility of the developer to stream data in the correct format into the secondary sound buffers The DirectSound mixing engine does not simply mix several sounds together It can also apply effects to a sound as it is written from a secondary buffer into the primary buffer Although these effects are audi ble using standard loudspeakers they are more obvious and compelling when the user wears headphones Basic effects are volume frequency control and panning changing the relative volume between
26. most cases a video adapter is a single self contained piece of PC hardware However there are some video add on devices that require access to video signals or the video adapter hardware A typical example of this may be a 3D graphics accelerator board that works in conjunction with the existing video adapter In order to access video signals or the video adapter hardware the video adapter provides a Video Feature Connector VFC similar to the 26 pin card edge connector shown in Figure 43 9 though many video adapters now use an IDC ribbon cable header The pinout for a classical 26 pin VFC is shown in Table 43 3 FIGURE 43 9 A typical video feature connector 1544 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS TABLE 43 3 PINOUT FOR A VIDEO FEATURE CONNECTOR PIN COMPONENT SIDE FUNCTION PIN SOLDER SIDE FUNCTION dal PDO DAC pixel data Zi Ground Y2 PD1 Z2 Ground VS PD2 Z3 Ground Y4 PD3 Z4 Select Internal Video Y5 PD4 Z5 Select Internal Syncs Y6 PD5 Z6 Select Internal DAC V7 PD6 Z Not used Y8 PD7 Z8 Ground Y9 DAC Clock Z9 Ground Y10 DAC Blanking Z10 Ground dan Ext Horiz Sync Z11 Ground Y12 Ext Vert Sync Z12 Not used Walls Ground Z13 Not used AMI MULTIMEDIA CHANNEL In addition to the classical VFC found on many video boards some current motherboards are incorpo rating advanced feature connectors to complement the on board video system American Megatrends AMD provides an AMI Multimedia Channel V
27. replace the COMCTL32 DLL file with a version that is not totally compatible with IE 5 Update the drivers to the latest versions For example Diamond Multimedia now has updated drivers that address this issue at www diamondmm com As an alternative you may extract a new copy of the COMCTL32 DLL file 4 Start Windows in the native DOS mode the Safe Mode Command Prompt 2 Rename the Comctl32 dil file in the Windows System folder to Comctl32 old by typing ren c windows system comct132 dll comct132 old at the command prompt and then press ENTER Now type extract c window 1 setupw95 cab comct132 dll 1 c windows system and then press ENTER 3 Restart the computer normally You notice a horizontal line scrolling down one side of the screen with multiple monitors under Windows 98 SE This problem is almost always caused when your monitors are too close to a fluorescent light source or you re using an unshielded monitor and you place it too close to another monitor Most early monitors are unshielded so they do not confine the mag netic field they emit Later monitors are shielded so that most of the magnetic fields they emit are con fined within the monitor If you place an unshielded monitor too close to another monitor the magnetic field emitted by the unshielded monitor may interfere with the other monitor Move the unshielded moni tor away from any monitors or fluorescent light sources it interferes with or place a shield such as an
28. smaller amount of colors for each texture instead of the normal 16 bit color values 65K colors This smaller color format CLUT requires less memory space than the true 65K colors so that more colors can be saved in memory to add detail to a scene AGP specifi cations also address this issue by allowing main system memory to be used for storing textures However most older 3D graphics accelerators do not support palletized textures so the information can be stored only in full 16 bit color format in the frame buffer utilizing all of the available off screen memory In such cases the extra textures will have to be stored and retrieved from system memory result ing in a serious hit on performance Alternatively textures can to be dropped from the scene by the graph ics accelerator in order to maintain performance Newer 3D graphics accelerators do provide full hardware support for palletized textures and allow developers to create very detailed scenes with two to four times as many textures This capability gives 3D applications a significant performance boost because the applications do not rely on the speed of the system to convert the information to 16 bit colors Texture mapping methods Texture mapping is a data intensive operation a bitmap is wrapped onto a 3D object or polygon to add more visual details thus enhancing realism The original bitmap used as the texture to be mapped is also called the source texture There are several ways t
29. the address of COM4 can be changed on the serial card usu ally via jumpers or the serial controller decodes all 16 bits of the I O port addresses There is no other way to get COM4 and any 8514 a compatible display adapter to coexist Keep in mind that this is an issue with the serial controller rather than the 8514 a video adapter TROUBLESHOOTING VIDEO ADAPTERS 1555 ATI Mach S3 Vision Trio and COM4 Conflicts As you saw in the last section 85 14 a video adapters will often conflict with COM4 because of poor I O address decoding ATT s Mach chipsets and S3 s chipsets are based on IBM s 8514 a standard and fre quently suffer the same problems as the 8514 a video adapters AWARD VIDEO BIOS GLITCH Motherboards using the Award Modular BIOS 4 50G series with Matrox video cards may have problems loading drivers under Windows 95 98 because the 4 50G series of Award BIOS is not Plug and Play compliant and cannot work under Windows 95 98 Upgrade the BIOS version on the motherboard to fix this problem and set the following CMOS configuration under the PCI Configuration Setup MB PCIIRQ Activated By LEVEL M If no other PCI devices are used in the system set the Slot X Using INT to AUTO E Make sure the PCI IRQ is assigned to the slot the video card is in VIDEO SYMPTOMS The computer is on but there is no display The PC seems to initialize properly If you hear a series of beeps during system initialization refer to Chapter 19
30. the left and right audio channels but DirectSound can also simulate 3D positional effects through the following techniques M Rolloff The further an object is from the listener the quieter it sounds This phenomenon is known as rolloff M Arrival offset A sound emitted by a source to the listener s right will arrive at the right ear slightly before it arrives at the left ear the duration of this offset is approximately a millisecond E Muffling The orientation of the ears ensures that sounds coming from behind the listener are slightly muffled compared with sounds coming from in front In addition if a sound is coming from the right the sounds reaching the left ear will be muffled by the mass of the listener s head as well as by the ori entation of the left ear M Doppler shift DirectSound automatically creates Doppler shift effects for any buffer or listener that has a velocity Effects are cumulative if the listener and the sound source are both moving the sys tem automatically calculates the relationship between their velocities and adjusts the Doppler effect accordingly MORE ON DIRECTINPUT DirectInput provides high performance access to input devices including the mouse keyboard joystick and the new force feedback input output devices that are arriving on the market DirectInput offers gen eralized device interfaces that support a much wider range of input and output devices than does the stan dard Win32 API functio
31. to determine the error Make sure that the monitor is turned on and plugged into the video adapter properly Also check that the monitor s brightness and contrast controls are turned up enough it sounds silly but it really does hap pen Try the monitor on a known good PC If the monitor works properly suspect the video adapter Power down the PC and make sure the video adapter is seated properly in its expansion slot If any of the board contacts are dirty or corroded clean the contacts by rubbing them with an eraser you can also use any electronics grade contact cleaner You may want to try the video board in another expansion slot Chances are that the video adapter has at least one hardware jumper or DIP switch setting Contact the manufacturer or refer to the owner s manual for the board and check that any jumpers or DIP switch set tings on the board are configured properly If this is a new installation check the adapter board settings against the configuration of other expansion boards in the system When the hardware settings of one board overlap the settings of another a hardware conflict can result When you suspect a conflict adjust the settings of the video adapter or another newly installed device to eliminate the conflict There may also be a memory conflict Some video adapters make unusual demands of upper system memory the area between 640KB and IMB It is possible that an EXCLUDE switch must be added to the EMM386 EXE entry
32. under Windows or the system hangs Thisis also a problem noted most often with Motion Pixels video boards and is almost always related to the use ofa WINDPMI 386 DPMI driver loaded through SYSTEM INI WINDPMI 386 reports the wrong amount of free lockable DPMI memory If your Windows platform is using Borland s WINDPMI 386 manually reduce the cache size with the c option or remove or disable the driver from SYSTEM INI entirely You might also consider upgrading WINDPMI 386 to a later version Contact Borland technical support or the technical support department of the video board maker QAR eR Other devices don t work properly after the PCI video card is installed For example the sound card output is distorted or a fast modem loses data This can happen often with newer video adapters Some computers require that software wait for the hardware to be ready TROUBLESHOOTING VIDEO ADAPTERS 1569 to receive new data Newer video board drivers are not normally set to do this because it slows them down slightly and it s not necessary for most current computers Under Windows 95 98 do the following 14 Right click on the Windows 95 desktop background Click the Properties menu item then select the video board s Settings tab Select the Advanced button then click the Performance tab Clear the Use automatic PCI bus retry check box a WO ND Finally accept your changes and reboot the computer when instructed to do so
33. use Adobe Type Manager E Remote control programs such as ppANYWHERE Verify that the correct display driver is installed for the secondary display device 1 Click Start highlight Settings click Control Panel then double click the Display icon 2 On the Settings tab click Advanced then click the Adapter tab 3 Verify that the installed video driver is the correct driver for the video adapter in your computer If it s not you should use the Update Driver wizard to install the correct driver s Verify that the secondary monitor displays the following message when you start your computer If you can read this message Windows has successfully initialized this display adapter To use this adapter as part of your Windows desktop open the Display option in the Control Panel and adjust the settings on the Settings tab If this message is not displayed confirm that the secondary display adapter is installed 1 Click Start highlight Settings click Control Panel then double click the System icon 2 On the Device Manager tab double click Display Adapters to confirm that all of your video adapters have been correctly installed If they haven t been you should recheck the installation of any missing devices 1554 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS M Verify that the secondary display adapter has a supported chip set as listed in Table 43 9 B If you notice that the Extend my Windows desktop onto this monitor box is unav
34. using Number Nine video boards with Alaris SLC2 motherboards The SLC2 microprocessor uses a 32 bit internal data bus but the external data bus seen by the motherboard is 16 bit Most of the registers on contemporary VL and PCI video boards are mapped as 32 bits and cannot be accessed as two 16 bit registers As a result the video board simply cannot be used together with the particular motherboard You will have to upgrade the motherboard or use a different video board Video playback experiences long pauses while the hard drive thrashes excessively This is a problem that appears under Windows 95 98 and is almost always the result of disk caching problems Start Windows Explorer and highlight the drivers responsible for video playback for a Motion Pixels video board highlight MPXPLAY EXE and MPXPLAY PIF Click the right mouse button and select Properties In the Memory page make sure that the Protected option has been set Restart the video clip or restart Windows 95 98 if necessary Also check your CONFIG SYS and AUTOEXEC BAT files and verify that there are no caching utilities being loaded You cannot use the loop through feature of your video board Typical examples include the Number Nine 9FX Motion 771 VGA loop through connector with a Reel Magic board and a Number Nine driver Unfortunately this is often the result of a limitation with the video board s graphics processor IC refusing to support loop through functionality To use loop
35. you to remove the old card and install the new one without the danger of driver conflicts or incompatible video modes Once the new card is installed you can easily return to the Display settings and configure the desired resolution and color depth again EXCHANGING THE VIDEO ADAPTER Now it s time to switch to your new video adapter This is generally not a difficult process but you ll need to pay attention to your particular system configuration Remember to use an antistatic wrist strap and to keep the new video card in its protective anti static bag until you re just ready to install it 1 Turn off and unplug the PC then remove the outer housing 2 Locate the original video adapter where the monitor cable attaches to the PC and disconnect the monitor cable 3 Ifthe original video adapter is integrated into the motherboard check the motherboard s user man ual to see if there s a jumper needed to disable that adapter If so set the required jumper so that the on board video adapter is disabled If you must disable the on board video adapter through the CMOS Setup we ll do that later 4 Ifthe original video adapter is simply an expansion card unbolt the bracket from the chassis and remove the original card Set it aside preferably in an antistatic bag 5 If you re replacing a PCI based video card with an AGP based video card check the mother board s user manual to see if there s a jumper to enable AGP support
36. 01 Display Settings Right next to the setting Resolution is an entry called ScreenArea This entry was left over from a for mer Virtual Desktop and was probably set to 640x480 Remove this key save your changes and reboot the system TROUBLESHOOTING VIDEO ADAPTERS 1559 Windows 95 reports a memory conflict with a PCI to PCI bridge and the AGP graphics adapter This PCI to PCI bridge is sometimes called the Intel 82443LX or 82443BX bridge This is not a real error The memory conflict that appears between the PCI bridge and the AGP graphics adapter is a known conflict This error is caused by the way Windows 95 reports mem ory usage and is not known to cause problems Windows 98 does not report this problem so you may ignore the issue or upgrade if you wish There are problems with IE 5 after installing 3D accelerator drivers For example you may experience problems if you install Diamond Multimedia Monster Fusion video drivers on a computer running Internet Explorer 5 In one case you may receive the following error after installing the Monster Fusion drivers on a system with IE 5 and restarting the PC EXPLORER caused an Invalid page fault in module EXPLORER EXE at 015f 00401f31 In another case Windows 95 98 may not start if you download and install Diamond video drivers from the Diamond web site and then restart your computer This trouble can occur because some Diamond video drivers
37. 2 bits needed to represent 1 pixel 4 pix els byte 64 000 4 16 000 bytes are still enough You can see that video RAM is directly related to video 1518 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS TABLE 43 1 INDEX OF VIDEO MODES RESOLUTION NUMBER OF COLORS VERTICAL FREQUENCY HZ 320x200 256 65K 70 85 320x240 256 65K 60 70 75 85 400x300 256 65K 60 70 75 85 512x384 256 65K 60 70 75 85 640x200 16 70 640x350 16 70 640x400 256 65K 16 7M 70 85 640x480 256 65K 16 7M 60 72 75 85 100 120 140 160 720x480 256 65K 16 7M 60 72 85 720x576 256 65K 16 7M 72 100 800x600 256 65K 16 7M 60 72 75 85 100 120 140 160 920x760 256 65K 60 75 85 1024x768 256 65K 16 7M 60 70 75 85 100 120 1152x864 256 65K 16 7M 60 70 75 85 100 120 1280x960 256 65K 60 75 85 1280x1024 256 65K 16 7M 60 70 75 85 100 1600x1024 256 65K 16 7M 60 76 85 1600x1200 256 65K 16 7M 60 65 70 75 80 85 100 1792x1344 256 65K 16 7M 60 75 1856x1392 256 65K 16 7M 60 75 1920x1080 256 65K 16 7M 60 72 75 85 1920x1200 256 65K 16 7M 60 76 85 1920x1440 256 65K 16 7M 60 75 85 2046x1536 256 65K 16 7M 60 75 capacity Since there is typically much more video RAM available than is needed for an image video boards support multiple video pages Figure 43 4 shows the pinout for a typical CGA video connector As with the earlier MDA design CGA video signals reserve pins and 2
38. DX GX S3MM DRV 1552 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS TABLE 43 9 VIDEO CHIPSETS DRIVERS SUITABLE FOR MULTI MONITOR OPERATION CONTINUED Diamond Stealth 64 Video 2001 STB PowerGraph 64V STB MVP 64 Miro 22SD Hercules Terminator 64 Video Number Nine 9FX Reality 332 S3 Virge Number Nine 9FX Reality 334 S3 Virge GX 2 Number Nine 9FX Reality 772 S3 Virge VX California Graphics V2 DX Videologic GraphicsStar 410 Cirrus 5436 CIRRUSMM DRV Cirrus Alpine Cirrus 5446 CIRRUSMM DRV STB Nitro 64V S3 VIRGE S3V DRV VIRGE 325 VIRGE VX 988 VIRGE DX 385 and VIRGE GX 385 Diamond Stealth 3D 2000 Diamond Stealth 3D 3000 Diamond Stealth 3D 2000 Pro Number Nine 9FX Reality 332 STB Nitro 3D STB Powergraph 3D STB Velocity 3D STB MVP 64 STB MVP 64 3D STB WorkStation 2 amp 4 output Miro Crystal VR4000 ET6000 ET6000 DRV Hercules Dynamite 128 Video STB Lightspeed 128 Compag Armada S3MM DRV Trident 9685 9680 9682 TRID_PCI DRV Jaton Video 57P Enabling Multi Monitor Support As you saw above the primary requirement for multi monitor support is that the video adapters must be Peripheral Component Interconnect PCI devices or Accelerated Graphics Port AGP devices You can enable multi monitor support with the following steps TROUBLESHOOTING VIDEO ADAPTERS 1553 6 While the computer is turned off add any additional video adapters and monitors Start Window
39. FC AMI V FC on some of its motherboards These con nectors are designed to maximize multimedia performance with the motherboard s video system and a connector is available for connecting multimedia building components such as MPEG or video capture modules to the system board Multiple protocols are supported through the same connector as follows M Standard VFC mode MB Digital video stream DVS mode MB MPEG data port MDP mode or multimedia peripheral port MPP mode Standard VFC mode This VESA compliant video feature connector interface synchronizes graph ics output and lets pass through signals from a video add in board use the motherboard s video circuits Table 43 4 lists the pinout for a 40 pin AMI VFC in the standard mode Note the similarities between the first thirteen pins of the classical VFC and the standard AMI VEC DVS mode In digital video stream DVS mode the interface is configured as a synchronous input port allowing the graphics controllers to be directly connected to certain video decoders through the VFC interface Some video decoders may require additional logic to encode the synchronization information within the data stream In DVS mode the AMI VFC consists of three independent signal groups an 8 bit data bus atwo wire serial bus and an audio interface The pinout for a 40 pin AMI VFC in the DVS mode is shown in Table 43 5 MDP MPP mode The MPEG data port MDP and multimedia peripheral port M
40. In most cases the CD s autorun feature will launch a menu driven installer that will allow you to load the card s drivers and support software 3Dfx Tools 3Dfx TV 3Dfx Tweaks and so on 3 Install the drivers and support software and reboot the system if necessary CHECKING THE INSTALLATION Once the software is installed and the system reboots you can check for the presence of your new video adapter card then reset the video mode to your liking 1 From the Windows desktop double click My Computer then double click Control Panel 2 Double click the System icon then select the Device Manager tab 3 Double click the Display Adapter entry to expand it 4 Check the display adapter reference You should see a reference to the new adapter that you just installed There should be no yellow exclamation marks or red Xs marking the adapter 5 Close the Device Manager and double click the Display icon 6 Click the Settings tab then click Advanced 7 Check for tabs that mention your new display adapter 3Dfx Info 3Dfx TV 3D Tweaks and so on If you see the entry for your new video adapter in the Device Manager and also in the advanced display settings dialog and no errors are indicated chances are that your new video adapter is working properly You may now return to the Settings tab in your Display dialog and set the desired resolution and color depth for your display Video Feature Connectors In
41. PP modes are mutually exclusive of each other the support for a particular mode is determined by the revision of the VIDEO FEATURE CONNECTORS 1545 TABLE 43 4 AMI MULTIMEDIA CHANNEL PINOUT STANDARD VFC MODE PIN DESCRIPTION PIN DESCRIPTION al DATAO Z1 DGND Y2 DATA1 Z2 DGND WS DATA2 LS DGND Y4 DATA3 Z4 EVIDEO WS DATA4 Z5 ESYNC Y6 DATAS5 Z6 EDCLK Wi DATA6 ZT Not used Y8 DATA7 Z8 DGND Y9 DCLK Z9 DGND Y10 BLK Z10 DGND Y11 HSYNC Zii VFSENSE Y12 VSYNC Z12 Not used Y13 DGND AIS Key Y14 Not used Z14 Not used Y15 Not used ZA Not used Y16 Not used 216 Not used Mara Not used alia Not used Y18 Not used Z18 Not used Y19 Not used Z19 Not used Y20 Not used Z20 Not used PIN DESCRIPTION PIN DESCRIPTION al DATAO Zil DGND Y2 DATA1 Z2 DGND YS DATA2 25 DGND Y4 DATA3 Z4 BS 1 WS DATA4 Z5 CONTRL Y6 DATAS5 Z6 SB Wi DATA6 ZT SDA Y8 DATA7 Z8 DGND Y9 CLK Z9 DGND Y10 BS 0 Z10 DGND Y11 Not used Zii VFSENSE Y12 Not used Z12 SCL Y13 DGND Zis Key Y14 Key Z14 Key Y15 SA Z15 5V 1546 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS TABLE 43 5 AMI MULTIMEDIA CHANNEL PINOUT DVS MODE CONTINUED PIN DESCRIPTION PIN DESCRIPTION Y16 SNRDY ZAG RESET Y17 MASKO Z17 Not used Y18 REV Z18 RESVD Y19 12V Z19 AGND Y20 AUDL Z20 AUDR graphics controller in use MPP provides a direct connection to an MPEG decoder It adds an additional multiplexed address data bus which can be used to conne
42. S SETTINGS The number of video BIOS settings has been increasing steadily even before the introduction of AGP Every video card should include a list of recommended BIOS settings with its documentation or available from the manufacturer s web site and you should see that your CMOS Setup is configured properly for your particular AGP video card For example look at the list of the recommended settings in Table 43 8 for a Viper II Z200 card and you ll get some idea of how important BIOS settings have become Not all listed options will be available on all motherboards Should particular setting combinations fail try loading BIOS Defaults in the CMOS Setup TABLE 43 8 TYPICAL BIOS SETTINGS FOR AN AGP CARD BIOS SETTINGS PCI AGP GENERAL IRQ assignment toggle Boot with PnP O S enable Pallet snooping disable PCI bursting disable PCI latency timer 128 Peer concurrency disable Video ROM BIOS Shadow disable Video BIOS shadowing disable Video BIOS cacheable disable Video RAM cacheable disable Byte Merge disable Decouple Refresh disable Hidden Refresh disable USWC options Uncache Speculative Write Combining Video Memory Cache Mode UC Snoop Ahead disable BIOS Settings AGP specific USB enabled PCI 2 1 compliance enable also may assign IRQ to VGA Passive release refresh enabled Delayed transactions enabled disabled toggle may also enable PCI 2 1 compliance
43. Under Windows 3 1x edit the SYSTEM INI file in your Windows directory to add the line PciChipSet 1 to the particular video board s section that is mga drv DAN ate Ey A Windows 95 98 game doesn t start or runs slower than normal The program uses the Microsoft DirectX interface DirectX may not be installed or an older version of DirectX is installed Most programs that use DirectX install it as part of their installation but some do not Also some older programs may install an earlier version of DirectX overwriting a later version To see if DirectX is installed 1 Right click on the Windows 95 98 desktop 2 Click the Properties menu item and select the video adapter s Settings tab 3 Click the Advanced button and click the Information tab 4 Lookatthe Microsoft DirectX Version label DirectX 5 x or later should be the current version If the current version of DirectX is installed you re finished Otherwise you II need to install DirectX If the DirectX setup program asks if you want to replace the existing display drivers click No You replace an older 3D accelerator with a newer one but the new accelerator is not working properly You often see this kind of trouble when replacing a 3Dfx Voodoo card or Monster I card with a newer card such as a Monster Fusion You ll need to remove the original Voodoo graphics card and clean out all of the old references to the card 3Dfx provides an INF file to remove these
44. VIDEO ADAPTERS AND ACCELERATORS CHAPTER AT A GLANCE Understanding Conventional Video Adapters 1515 Text vs Graphics ROM BIOS Video BIOS Reviewing Video Display Hardware 1517 MDA Monochrome Display Adapter 1981 CGA Color Graphics Adapter 1981 EGA Enhanced Graphics Adapter 1984 PGA Professional Graphics Adapter 1984 MCGA Multi Color Graphics Array 1987 VGA Video Graphics Array 1987 8514 1987 SVGA Super Video Graphics Array XGA 1990 Understanding Graphics Accelerators 1522 Video Speed Factors 3D Graphics Accelerator Issues 1531 The 3D Process Key 3D Speed Issues Improving 3D Performance Through Hardware Understanding DirectX 1536 Pieces of a Puzzle More on DirectDraw More on DirectSound More on DirectInput More on Direct3D More on DirectPlay Determining the Installed Version of DirectX Replacing Updating a Video Adapter 1540 Removing the Old Device Drivers Exchanging the Video Adapter Installing the New Software Checking the Installation Video Feature Connectors 1543 AMI Multimedia Channel AGP Overclocking 1547 AGP and BIOS Settings Troubleshooting Video Adapters 1549 Isolating the Problem Area Multiple Display Support Guide Unusual Hardware Issues Award Video BIOS Glitch Video Symptoms Further Study 1570 The monitor itself is merely an output device a peripheral that translates synchronized analog or TTL Transistor to Transistor Logic video signal
45. YS file 1 Open the CONFIG SYS file using any text editor such as Notepad 2 Add the following lines device lt windows gt himem sys device lt windows gt emm386 exe x c000 cfff where lt windows gt is the path to the folder in which Windows is installed 3 Save and then close the CONFIG SYS file 4 Restart your computer The screen image becomes distorted when changing resolutions This is known to occur with certain monitors under Windows 98 such as the NEC 4FG Some video adapters such as the Diamond Stealth 64 Video 2001 and S3 Trio 64V default to a refresh rate of 60Hz NEC 4FG monitors can support only refresh rates of less than 60Hz at a resolution of 1280x1024 or higher For example if you re using an NEC 4FG monitor and you change the display resolution to 1280x1024 or higher your screen may become distorted This trouble can occur if you re using a video adapter that defaults to a refresh rate of 60Hz at such high resolutions To correct this fault optimize the refresh rate of your video adapter before you attempt change the display resolution Click Start highlight Settings then click Control Panel Double click the Display icon Select the Settings tab then click Advanced Click the Adapter tab then click Optimal in the Refresh Rate box a OO ND Click OK then click OK again when you receive the following message Windows will now adjust the refresh rate of your display The screen may fl
46. ady or saved the CMOS contents to floppy disk using a CMOS backup utility Once new settings are entered and saved the system should operate properly If the CMOS still will not retain system configuration information the CMOS RAM itself is probably defective Use a software diagnostic to check the RTC CMOS IC and the rest of the motherboard thoroughly If a motherboard fault is detected you can troubleshoot the motherboard or replace it outright at your discretion TROUBLESHOOTING VIDEO ADAPTERS 1557 Garbage appears on the screen or the system hangs up There are a variety of reasons why the display may be distorted One potential problem is a monitor mismatch Check the video adapter jumpers and DIP switch settings and be sure that the video board will support the type of monitor you are using It is possible that the video mode being used is not supported by your moni tor the display may also roll as described in Symptom 43 4 Try reconfiguring your application soft ware to use a compatible video mode The problem should disappear If it doesn t you will have to upgrade to a monitor that will support the desired video mode Some older multi frequency monitors are unable to switch video modes without being turned off then turned on again When such monitors experience a change in video mode they will respond by dis playing a distorted image until the monitor is reset If you have an older monitor try turning it off wait several min
47. ailable you can select the secondary monitor and try extending the desktop again 1 Click Start highlight Settings click Control Panel then double click the Display icon 2 Onthe Settings tab click the secondary monitor icon After you click the secondary monitor icon the Extend my Windows desktop onto this monitor check box should become available UNUSUAL HARDWARE ISSUES A lot of emphasis is placed on drivers and software configurations but there are also quite a few unique hardware problems that can affect your video system Some of the most frequent problems are outlined in the following sections Clock Speed and the VL Bus Video boards that use the VL bus are very sensitive to motherboard clock speeds over 40MHz If your motherboard runs the VL bus at over 40MHz it s quite possible that you will have trouble with VL bus video boards The VESA specification states that one card can operate at 4OMHz or two can operate at up to 33MHz a best case scenario Some manufacturers don t even guarantee that their cards will run at 40MHz preferring to support bus speeds of 33MHz or less So if your VL bus video board is running at over 40MHz and it refuses to run properly your best option is usually to step your bus speed down Bus speeds can usually be controlled by a motherboard jumper or an entry in CMOS If you cannot change bus speed for any reason try a different brand of VL card Version 2 0 of the VESA VL Bus specifi
48. ake advantage of the sys tem level services provided by the DirectX foundation The media level services are device independent and include features such as animation behaviors and video streaming The DirectX media layer includes five APIs MB Direct3D Retained Mode offers a collection of 3D scene features DirectPlay supports multiplayer network play DirectShow handles slide show type operation and features DirectAnimation supplies animation support DirectModel supplies 3D modeling support Components The components layer makes up the top level of the DirectX hierarchy These are a group of application specific modules that can draw on all features available in the media and foundation layers DirectX components include NetMeeting an online white board for real time group collabora tion ActiveMovie a set of tools for rendering full screen MPEG video and supporting playback of a wide range of audio and video formats and Netshow enabling live broadcast of rich multimedia content over the Internet along with the compelling 3D worlds of VRML MORE ON DIRECTDRAW Most Windows programs access drawing surfaces indirectly through Win32 device context functions such as GetDC The application then writes indirectly to the device through the graphics device interface or GDI system The GDI is the Windows component that provides an abstraction layer that enables all standard Windows applications to draw to the screen
49. ally all subsequent video adapters now use the 15 pin analog format shown in Figure 43 6 While MCGA adapters are also technically obsolete the standard lives on in MCGA s cousins VGA and SVGA VGA Video Graphics Array 1987 The Video Graphics Array or VGA was introduced along with MCGA and implemented in other mem bers of IBM s PS 2 series The line between MCGA and VGA has always been a bit fuzzy since both were introduced simultaneously both using the same 15 pin video connector and VGA can handle every mode that MCGA could For all practical purposes we can say that MCGA is a subset of VGA It is VGA that provides the familiar 640x480x16 screen mode that has become the baseline for Microsoft Windows 95 98 Safe Mode displays The use of analog color signals allows VGA systems to produce a palette of 16 colors from 262 144 possible colors VGA also provides backward compatibility for all older screen modes Although the PS 2 line has been discontinued the flexibility and backward 1 Red 2 Green 3 Blue 1 5 4 Ground 5 Ground 6 Red ground 7 Green ground 8 Blue ground 6 10 9 n a 10 Ground 11 Ground 12 n a 11 15 13 Horizontal sync VGA MCGA 14 Vertical sync General analog 15 n a FIGURE 43 6 Pinout of a VGA MCGA SVGA video connector REVIEWING VIDEO DISPLAY HARDWARE 1521 compatibility of VGA proved so successful that VGA adapters were soon developed for the PC For a time VGA support was considered t
50. ation for each screen pixel rather than ASCII characters so the character ROM and character gen erating circuitry used in text mode is bypassed For example monochrome graphics uses a single bit per pixel 16 color graphics uses 4 bits per pixel 256 color graphics uses 8 bits per pixel and so on Pixel data taken from VRAM by the CRTC is passed through the character generator without any changes Data is then sent directly to the shift register and on to the signal generator It is the signal generator that produces analog or TTL video signals along with sync signals as dictated by the CRTC Signals to the monitor PC bus interface Attribute data Attribute generator Character ROM I Character Shift generator register Character data Display controller IC Sync signals FIGURE 43 2 Block diagram of a frame buffer video adapter REVIEWING VIDEO DISPLAY HARDWARE 1517 ROM BIOS Video BIOS There is one part of the classic video adapter that has not been mentioned yet the video BIOS The dis play controller requires substantial instruction changes when it is switched from text mode to any one of its available graphics modes Since the instructions required to re configure and direct the CRTC depend on its particular design and the video board design in general it is impossible to rely on the particular software application or the PC s BIOS to provide the required s
51. ator performance Even the finest accelerator board hardware can bog down when run under careless loosely written code There are two classes of software that you must be concerned with video BIOS and video drivers The video BIOS is firmware software that is per manently recorded on a memory device such as aROM Video BIOS holds the programming that allows the accelerator to interact with DOS applications software Current adapters have flash upgradeable BIOS ROMs that allow the video adapter s firmware to be updated without removing the video adapter from the PC VESA BIOS extensions are now being used almost universally as part of the video BIOS for many accelerators as well as conventional frame buffer adapters Adding VESA BIOS extensions to video BIOS eliminates the need to load another device driver under DOS However there are compelling advantages to video drivers Windows 95 98 works quite well with drivers and generally ignores video BIOS entirely Unlike BIOS ROMs which can be troublesome to upgrade a video driver can change very quickly as bugs are corrected enhancements are made and per formance is streamlined The driver can be downloaded from a manufacturer s BBS or web site on the UNDERSTANDING GRAPHICS ACCELERATORS 1529 Internet or other online information service such as AOL and installed on your system in a matter of min utes without any disassembling of the PC It is also possible for you to use third party vi
52. ay produce a board that reaches only 640x480x 16M more than 16 million colors This mixing and matching of resolutions and color depths has resulted in a very competitive but very fractured market no two SVGA boards are necessarily capable of the same things This prolifera tion of video hardware also makes it impossible for applications software to take advantage of super video modes without supplemental software called video drivers Video drivers are device drivers loaded before an application program is started that allow the particular program to work with the SVGA board hardware Video drivers are typically developed by the board manufacturer and shipped on a floppy disk with the board Windows 95 98 takes particular advantage of video drivers since the Windows interface allows all Windows applications to use the same graphics system rather than having to write a driver for every application as with DOS Using an incorrect obsolete or corrupted video driver can be a serious source of performance and stability problems for SVGA installations The one common attribute of SVGA boards is that most offer full support for conventional VGA which requires no video drivers so Windows can always be started safely in the conventional 640x480x16 VGA mode There are only a handful of SVGA board manufacturers that have abandoned conventional VGA support Today most SVGA boards offer terrific video performance a wide selection of modes and
53. cation didadd support for a 50MHz bus speed Unfortunately VESA VL bus 2 0 is one of a few VESA specs that went largely ignored by video manufacturers Just because the VL bus 2 0 specification exists do not assume that any VL bus motherboard will be compatible SLC Motherboards and the VL Bus If you have an older motherboard using an 1486SLC type CPU some VL bus video boards will not oper ate properly when used with that particular motherboard This reason is that the 32 bit VL bus was not implemented properly in conjunction with the 16 bit data path of the i486SLC this is a problem with the motherboard s design not the particular video boards Later model motherboards with the i486SLC CPU largely overcame this problem take care however when using any VL bus video board on i486SLC motherboards Chances are that an older ISA video board will work just fine 8514 a and COM4 Conflicts The 8514 a video adapter was designed to coexist with a VGA adapter To achieve this condition the 8514 a uses a different range of addresses Some of these are 16 bit addresses that are located at 42E8h 82E8h 92E8h A2E8h and E2E8h Unfortunately many serial controllers decode only the first 12 bits of the I O port address and assume that calls to x2E8h like all of those listed above are intended for the serial port that is 2E8h rather than the video card Therefore COM4 cannot be used on most machines with an 8514 a compatible video card unless
54. cimal code shown on the POST card indicators The last code to be displayed is the point at which the failure occurred POST cards are handy for checking the motherboard when a low level fault has occurred If a motherboard fault is detected you may troubleshoot the motherboard or replace it outright at your discretion You see large blank bands at the top and bottom of the display in some screen modes but not in others Multi frequency and multi mode monitors sometimes behave this way This is not necessarily a defect but it can cause some confusion unless you understand what is going on When screen resolution changes the overall number of pixels being displayed also changes Ideally a multi frequency monitor should detect the mode change and adjust the vertical screen size to compensate a feature called auto sizing However not all multi frequency monitors have this feature When video modes change you are left to adjust the vertical size manually Of course if there is information missing from the display there may be a serious problem with VRAM or the adapter s graph ics controller chip In this event try another video adapter board The display image rolls Vertical synchronization is not keeping the image steady horizontal sync may also be affected This problem is typical of a monitor that cannot display a particular screen mode Mode incompatibility is most common with fixed frequency monitors but it can also appear in multi freque
55. cing a failed video adapter you ll need to install a new video card with confidence In virtually all cases you ll need to remove references to any original video card first replace the old card with the new one then install the new drivers and video applet software under Windows 95 98 This part of the chapter highlights the gen eral steps needed to upgrade your video system REMOVING THE OLD DEVICE DRIVERS New video adapters can be quite sensitive to drivers and applet software from an old video device so it s usually important for you to remove the drivers and all support software for your current video device before removing the old card and installing the new one Of course if you re installing a video device into anew system you won t have to worry about this step To remove the display utilities or control panels for REPLACING UPDATING A VIDEO ADAPTER 1541 a display card you are currently using you must first locate and identify them There are four main places where you should look for these items Check the user s guide installation instructions or owner s manual for the card you re about to remove Any programs that would have been added to your system when you installed the card should be described in the documentation There may also be specific instructions for uninstalling the card s software from your system if so you should use those instructions to remove the card s software suite Many vi
56. ct a range of third party devices like MPEG2 decoders or audio processors This bus uses ISA type control and either an 8 bit or 16 bit protocol The fully programmable control signals allow it to interface to a variety of devices with minimal external logic Table 43 6 illustrates the pinout for an AMI VFC in MDP mode while Table 43 7 shows the pinout for an AMI VFC in the MPP mode TABLE 43 6 AMI MULTIMEDIA CHANNEL PINOUT MDP MODE PIN DESCRIPTION PIN DESCRIPTION Wal DATAO Zi DGND Y2 DATA Z2 DGND We DATA2 Z3 DGND Y4 DATA3 Z4 IOR YS DATA4 Z5 IOW Y6 DATA5 Z6 RDY INT Y DATA6 Z7 SDA SAD4 Y8 DATA7 Z8 DGND Y9 DCLK Z9 DGND Y10 SADO Z10 DGND Y11 SAD1 Z11 VFSENSE Y12 SAD2 Z12 SCL Wg DGND Zale Key Y14 Key 214 Key Walls SAD3 Z15 5V Y16 SAD7 Z16 RESET Wall SAD5 zii SAD6 Y18 REV Z18 RESVD Y19 12V Z19 AGND Y20 AUDL Z20 AUDR AGP OVERCLOCKING 1547 TABLE 43 7 AMI MULTIMEDIA CHANNEL PINOUT MPP MODE PIN DESCRIPTION PIN DESCRIPTION val DATAO Zi DGND Y2 DATA Z2 DGND ie DATA2 Z3 DGND Y4 DATA3 Z4 IOR WS DATA4 Z9 IOW Y6 DATA5 Z6 RDY INT Wa DATA6 z SDA Y8 DATA7 Z8 DGND Y9 DCLK Z9 DGND Y10 SADO Z10 DGND Walia SAD1 Z11 VFSENSE Y12 SAD2 Z12 SCL Walls DGND 213 Key Y14 Key 214 Key MS SAD3 Z15 5V Y16 SAD7 Z16 RESET Walla SAD5 Zim SAD6 Y18 REV 218 SAD4 Wald 12V 219 AGND Y20 AUDL Z20 AUDR AGP Overclocking The AGP bus was designed as a 66MHz bus architecture and this 66MHz signal is a
57. d Run some PC diagnostics if you have some available Diagnostics may help to pinpoint motherboard prob lems You may then choose to troubleshoot the motherboard further or replace the motherboard outright at your discretion When the video system appears to work properly during system initialization but fails with a particu lar application or in Windows 95 98 strongly suspect a problem with the selected video driver Since almost all video adapters support VGA at the hardware level set your application or change the Windows setup to run in standard VGA mode for Windows 95 98 you can start the PC in the Safe Mode If the display functions properly at that point you can be confident that the problem is driver related Check with the manufacturer to see that you have the latest video driver available Reload the driver from its orig inal disk or a new disk or select a new driver If the problem persists in VGA mode the trouble may be in the video adapter Problem isolation can be summarized by the points below M Check the driver s Video drivers are critically important in Windows 3 1x 95 98 Older drivers may contain bugs or be incompatible with certain applications This situations account for the major ity of all video problems Obtain the latest video driver release and make sure it is properly installed on the system If the driver is current try a generic video driver usually available from the video chipset manufacturer
58. d at 8 33 MHz you can see how a serious data transfer bottleneck develops Even the PCI bus can be strained by higher video modes though the high bandwidth data channel provided by AGP has eased this bottleneck Such video data bottlenecks result in painfully slow screen refreshes especially under Windows which requires frequent refreshes Video designers seek to overcome the limitations of conventional video adapters by incorporating processing power onto the video board itself rather than relying on the system CPU for graphic process ing By off loading work from the system CPU and assigning the graphics processing to local processing components graphics performance can be improved by a factor of three or more There are several means of acceleration the availability of which depends on the sophistication of the board Figure 43 7 Fixed function acceleration relieves load on the system CPU by providing adapter support for a limited number of specific functions such as BitBlt or line draws Fixed function accelerators were an improve ment over frame buffers but they do not offer the performance of more sophisticated accelerators A graphics accelerator uses an application specific chip or ASIC that intercepts graphics tasks and pro cesses them without the intervention of the system CPU Graphics accelerators are perhaps the most cost effective type of accelerator Graphics co processors are the most sophisticated type of accelerator T
59. d to the XGA design XGA is generally limited to high performance applications in MicroChannel systems The migration to ISA based PCs has been slow because the ISA bus is limited to 16 bits and does not support bus mastering as Micro Channel busses do For PCs SVGA adapters using the high performance PCI and now the AGP bus will likely provide extended screen modes as they continue to grow in sophistication as graphics accelerators Understanding Graphics Accelerators When screen resolutions approach 640x480 and higher the data needed to form a single screen image can be substantial Consider a single 640x480x256 image There are 640x480 307 200 pixels Since there are 256 colors 8 bits are needed to define the color for each pixel This means 307 200 bytes are needed for every frame When the frame must be updated 10 times per second 307 200 x 10 3 072 000 bytes per second 3 072MB sec must be moved across the bus PCI or ISA bus If a 65 536 color mode is being used 2 bytes are needed for each pixel so 307 200 x 2 614 400 bytes are needed for a frame At 10 frames per second 614 400 x 10 6 144 000 bytes per second 6 144MB sec must be moved across the bus this is just for video information and does not reflect the needs of system overhead operations such as memory refresh keyboard and mouse handling drive access and other data intensive system opera tions When such volumes of information must be moved across an ISA bus limite
60. deo drivers Hard ware manufacturers are not always adept at writing efficient software and a third party driver developed by an organization that specializes in software may actually let your accelerator perform better than the original driver shipped from the manufacturer Reference drivers are often available from the video chipset maker s web site Video board manu facturers typically customize these drivers for their specific product Customized reference drivers often include performance improvements but can be unstable because they have not been tested on or written for specific video cards The RAMDAC Just about every analog video system in service today is modeled after the 15 pin VGA scheme which uses three separate analog signals to represent the three primary colors The color for each pixel must be broken down into component red green and blue levels and those levels must be con verted into analog equivalents The conversion from digital values to analog levels is handled by a digi tal to analog converter or DAC Each conversion also requires a certain amount of time Faster DACs are needed to support faster horizontal refresh rates Current video boards incorporate RAMDAC rated at up to 350MHz which can support very high resolutions at reasonably high refresh rates Remember that each video adapter uses a palette which is a subset of the colors that can possibly be produced Even though a monitor may be able to produce
61. deo related programs add an item under the Programs entry on your Start menu Such an item may be listed by the name of the display card it is associated with or by the name of the company that manufactured the card Display utilities and control applets are often given their own specific names like the 3dfxTools software for a new Voodoo3 card If you find such a menu entry look to see if there s an Uninstall option If you find an Uninstall feature that s probably the best way to remove the software from your system The Windows Control Panel probably contains the actual program icons for any display utilities or control applets that may have been installed with the existing video card This may help you to iden tify the program you wish to remove though it probably will not give you a direct method for remov ing it However the Add Remove Programs wizard in the Control Panel can probably remove the software for you once you know what software to remove The Windows StartUp folder may contain a shortcut to a display utility or control applet for the exist ing video card If so you can simply delete the shortcut from the StartUp folder to disable the program but doing that will not remove the software from your system You may also wish to use the Add Remove Programs icon in the Control Panel to actually remove that software from your system Once the applet software is removed from the system it s time to select a default vide
62. e Further Study 3dfx http www 3dfx com index html 3DLabs http www 3dlabs com index html ATI http www atitech ca Creative Labs http www americas creative com home html Data Expert http www dataexpert com tw Diamond Multimedia http www diamondmm com Purchased by S3 DirectX http www microsoft com directx Fast Graphics http www fastgraphics com Guillemot http www guillemot com Hercules http www hercules com Purchased by Guillemot Intel AGP http developer intel com technology agp tutorial index htm Matrox http www matrox com Maximum Hardware http www maximumhardware com Number Nine http www nine com Nvidia http www nvidia com Oak http www oaktech com S3 http www s3 com STB http www stb com Purchased by 3dfx Trident http www trid com Tweak 3D http www tweak3d net VESA Standards http www vesa org Video Logic http www videologic com Voodoo Extreme http www voodooextreme com
63. e technique of anti aliasing is used for disguising the jagged edges of a curved line or a line with very low or very high slope These jagged edges are especially visible at lower resolutions with each pixel appearing as a stair step rather than a smooth line Anti aliasing is a way to use color information to make up for a lack of screen resolution It simulates higher resolution by using color infor mation to trick our eye into seeing a smoother line or edge than the screen can physically allow By adding pixels of a slightly different color next to the line or curve at the transition points the edge is blurred The eye sees this blur as a smooth edge rather than a different color Understanding DirectX When Windows first emerged as a major operating system its focus was primarily on file management and utilities High performance graphics and other forms of multimedia were barely even dreamed of This ini tial approach made it very difficult for Windows later to support graphics intensive applications such as games DVD PC TV or MPEG video and is largely the reason why DOS lingered for so long on many PC platforms Developers realized that in order for Windows to finally become independent of DOS a means of supporting high performance multimedia functions would be required and DirectX technology was born With Windows 95 DirectX emerged as a key element in graphics sound and interaction for multime dia platforms This part o
64. e very latest drivers and support components The computer is running very slowly poor performance and the hard drive light is continuously lit This problem is particularly apparent with Diamond Edge 3D video boards on systems with more than 16MB of RAM The Diamond Edge 3D board comes with both 1MB and 6MB MIDI bank files Diamond recommends that you use only the 6MB bank file on systems with over 16MB of RAM To change the size of the MIDI bank file being used Right click on My Computer and choose Properties Open the System Control Panel and click on the Device Manager tab Click on the symbol beside the Sound Video and Game Controller line Highlight Diamond EDGE 3D PCI Multimedia Device click on Properties and the click on Settings 5 Youwill then see the 1MB and 6MB MIDI bank selection Select the 6MB option choose OK and restart your computer when prompted bh ND SA ae EEE TX You notice that AVI files have distorted colors or grainy playback This symptom usually occurs when playing 8 bit AVI files that are not supported by DCI and can usually be corrected by disabling the accelerated video playback features of the video board For example the older Diamond ViperPro Video board is noted for this problem and you would need to edit the COPRO INI file located in the windows directory In the VCP area change the VCPEnable line to OFF Save the INI file and restart Windows The PCI video board w
65. egrity of video RAM you may have to replace the video RAM or replace the video board entirely You encounter video related conflicts in Packard Bell systems The system refuses to boot or starts with garbage and erratic screen displays This symptom is encoun tered most frequently with Boca video boards on Packard Bell systems with video circuits already on the motherboard Even when the on board video has been disabled reports indicate that the video circuitry remains active and then conflicts with the add on video board Packard Bell indicates that their Vxxx 16 BIOS will correct this problem so contact Packard Bell for an appropriate BIOS upgrade Text appears in an odd color For example text that should be green appears black This is almost always the result of a problem with the palette decoding registers on the par ticular video board and will typically appear when using higher color modes 64k or 16M colors for example Make sure that the video drivers are correct complete and up to date If the problem persists you may need to replace the video board outright Remember that you can select myriad color and text schemes under Windows 95 98 Before you conclude that color problems are caused by a faulty video card be sure to try the Windows Default desktop scheme When an application is started under Windows the opening display appears scrambled While this might appear to be a video memory problem at first
66. em BIOS did not complete the config uration of the video board correctly and the board has not been enabled onto the PCI bus The video board manufacturer may have a utility available which can remap the video card to a new address outside of physical memory For the Matrox Millennium use the PCIMAP EXE utility Other Matrox boards use the MGABASE EXE utility Other PCI video board manufacturers probably offer their own utilities The second potential problem is that the system BIOS has assigned a base memory address to the video board that is used by another device or is reserved for use by the motherboard chipset While the utilities men tioned above may often help to correct this problem a more permanent fix is usually to update the system BIOS Investigate a BIOS upgrade from the motherboard or PC manufacturer The monitor overscans when entering a DOS shell from Windows This creates a highly distorted image and can damage the monitor circuitry if left for prolonged periods The cause of this problem is usually a bug in the video driver For example this type of problem is known to happen when using the older Diamond SpeedStar Pro with drivers prior to version 1 06 Obtain the latest video driver from the video board maker or try a generic video driver written by the video chipset maker VA ate Ey You encounter an intermittent Divide by Zero error Although there are several possible causes for this type of error they are all rela
67. equency For Matrox boards you can correct the problem by modifying the DVMCIMIL INI file found in the WINDOWS directory Under the Carrier section change the CarrierType 0 entry to CarrierType 1 Other video TV boards may utilize different INI entries or allow carrier selection through the use of an onboard jumper but poor reception is almost always the result of an unusual cable carrier DAN ate ee Rt You encounter errors such as Insufficient video memory There is not enough video memory on the board to handle screen images at the resolution and color depth you have selected In most cases the system may crash outright Your immediate solution should be to select a lower resolution or smaller color palette If you are encountering such problems when attempting to play AVI or MPEG files you should be able to select smaller video windows and lower color depth without altering your Windows setup As a more long term solution you should consider adding more video memory or replacing the video board with one that contains more video memory The PCI video board is not working properly there is a BIOS conflict with PCI interrupt 1Ah The lower 32KB of the ROM BIOS has been redirected for high memory use Disable this memory with your memory manager by adding an exclude command such as x f000 f7ff You encounter video corruption or sporadic system rebooting when using an SLC type motherboard This particular symptom has been most noted when
68. es not have any representation of a physical machine in the session Each player is identified as being either a local player one that exists on your machine or a remote player one that exists on another machine and each machine must have at least one local player before it can start sending and receiving messages DirectPlay supports the concepts of groups within a session A group is logical collection of players By creating a group of players an application can send a single message to the group and all the players in the group will receive a copy of the message DETERMINING THE INSTALLED VERSION OF DIRECTX Since DirectX is a collection of APIs each application that uses DirectX is written to use a particular ver sion of DirectX the application needs the correct version of DirectX components installed under Win dows 95 98 Otherwise the application will not work In most cases DirectX is backward compatible so an application written for DirectX 3 x should work on a system with DirectX 5 x installed But an applica tion written for DirectX 5 x won t work on a system with DirectX 3 x As a technician you ll need to spot DirectX version issues You can use the following procedure to check the current version of DirectX installed on a given system 1 Using Windows Explorer or My Computer locate the DDRAW DLL file in the Windows System folder 2 Use the right mouse button to click the DDRAW DLL file and then click Properties on t
69. es the potential bandwidth of the AGP connection to 1 06GB sec A significant AGP feature is its ability to access system memory directly during rendering In this situa tion system memory is referred to as Non Local Memory NLM The operating system can reserve por tions of the system s main memory for use by the graphics controller There are two methods of using NLM supported by Intel s AGP specifications and both require support from the operating system through an API such as DirectDraw to utilize NLM for texture map storage and some z buffering The first method is through Direct Memory Access DMA The DMA mode utilizes NLM only for mass storage of informa tion like texture data This restriction which allows the graphic controller to keep fewer texture maps in local memory on the video board is mainly intended to reduce system cost Non Local Memory can be used for texture maps thus allowing applications such as games to use larger maps this process improves 3D GRAPHICS ACCELERATOR ISSUES 1531 game realism and image quality without sacrificing performance or requiring more expensive local mem ory Direct Memory Execute or DiME is the second mode used by AGP adapters to utilize NLM In this mode often referred to as Execute Mode 3D functions are actually performed in Non Local Memory and the end result is then transferred to the graphics adapter for display DiME can actually impair perfor mance if the graphics ada
70. f the chapter offers a basic overview of DirectX and its components PIECES OF A PUZZLE Contrary to popular belief DirectX is not one single piece of software Instead DirectX is actually a com prehensive collection of Windows 95 98 APIs Application Programming Interfaces that provide a stan dardized set of features for graphics sound input devices multiplayer interaction and application setup DirectX software is categorized into three layers a foundation layer a media layer and a components layer Foundation The foundation layer forms the heart and soul of DirectX It is a set of low level APIs that are the basis for all high performance multimedia under Windows 9x DirectX foundation APIs pro vide direct access to hardware acceleration such as 3D graphics acceleration chips in effect allowing Windows 9x to talk directly to hardware The foundation layer uses the following APIs DirectDraw provides graphics surface management Direct3D Immediate Mode supplies low level 3D features used in conjunction with DirectDraw DirectInput supports arich selection of input devices including new force feedback joysticks DirectSound provides sound and mixer effects DirectSound 3D offers 3D sound effects from ordinary 2D speaker arrangements DirectSetup installs software and drivers automatically UNDERSTANDING DIRECTX 1537 Media The DirectX media layer consists of application level APIs that t
71. f the intersecting objects are visible However many software developers do not use a z buffer for all objects in the scene They do not because the z buffer takes up space in the off screen memory that could be used instead to store extra source tex tures for greater detail For this reason many 3D graphics chips provide an optional z buffer allowing the developer to decide whether to use the off screen memory for z buffering or texture storage If a game using a z buffer such as Quake IT is played on a graphics accelerator that does not allow for a hardware z buffer the game will not run or will run at very low frame rates since all z buffering will need to be done in software This is where AGP s use of Non Local Memory for texture storage and z buffering helps to improve performance Palletized textures Storing source textures of 3D games in off screen memory is very taxing on the graphics frame buffer Each time a new scene is created all of its source textures need to be loaded in off screen memory for use by the graphics chip Memory available to store textures is limited because a 3D game accelerator generally has about 8MB of memory This limit restricts the number of textures effectively reducing the detail and quality available in a scene To compensate for this developers can use a method of palletized textures which assigns a Color Look Up Table or CLUT to each texture in the scene This technique allows the developer to use a
72. g a set of secondary color signals or color intensity signals such as Red Intensity 2 Green Intensity 6 and Blue Intensity 7 the total of six color control signals allow the EGA to produce up to 64 possible colors Although 64 colors are possible only 16 of those colors are available in the palette at any one time Pin 8 carries the horizontal sync signal pin 9 carries the vertical sync signal and pin 1 remains ground PGA Professional Graphics Adapter 1984 The Professional Graphics Adapter was also introduced in 1984 This system offered a then revolutionary display capability of 640x480x256 Three dimensional rotation and graphic clipping was included as a hardware function and the adapter could update the display at 60 frames per second The PGA was incredibly expensive and beyond reach of all but the most serious business user In actual operation a PGA system required two or three expansion boards so it also represented a serious commitment of lim ited system space Ultimately PGA failed to capture any significant market acceptance It is unlikely that you will ever encounter a PGA board most that ever saw service in PCs have long since been upgraded Ground Red intensity Primary red Primary green Primary blue Green intensity Blue intensity Horizontal sync Vertical sync SONORA CR Col 6 EGA 10 FIGURE 43 5 Pinout of an EGA video connector 1520 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS MCGA Multi Color
73. he co processor acts as a CPU that is dedicated to handling image data Older graphics co processors such as the TMS34010 and TMS34020 represent the Texas Instruments Graphical Architecture TIGA which is broadly used for high end accelerators Unfortunately not all graphics co processors provide increased performance at a level that warrants the higher cost UNDERSTANDING GRAPHICS ACCELERATORS 1523 Feature connector Graphics accelerator FIGURE 43 7 A typical video accelerator board Figure 43 8 shows the block diagram for a basic graphics accelerator The core of the accelerator is the graphics chip or video chipset The graphics chip connects directly with the PC expansion bus Graphics commands and data are translated into pixel data which is stored in video RAM High perfor mance video memory offers a second data bus which is routed directly to the video board s RAMDAC random access memory video to analog converter The graphics chip directs RAMDAC operation and ensures that VRAM data is available The RAMDAC then translates video data into red green and blue analog signals along with horizontal and vertical synchronization signals Output signals generated by the RAMDAC drive the monitor This apparent simplicity of the architecture is due to the extremely high level of integration provided by the chipsets being used Table 43 2 provides a listing of many 2D and 3D graphics chipsets
74. he menu that appears 3 Click the Version tab 1540 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS 4 Compare the version number on the File Version line with the following list 4 02 0095 DirectX 1 4 03 00 1096 DirectX 2 4 04 00 0068 DirectX 3 or 3a 4 05 00 0155 DirectX 5 4 05 01 1721 DirectX 5 1 4 05 01 1998 DirectX 5 2 Windows 98 and later 4 06 02 0436 DirectX 6 1 4 06 03 0518 DirectX 6 1a 4 07 00 0700 DirectX 7 and 7a DirectX versions 3 and 3a use the same version of the DDRAW DLL file To determine whether you are using version 3 or 3a of DirectX use the procedure above to check the version of the D3DRGBXF DLL file 4 04 00 0068 DirectX 3 4 04 00 0070 DirectX 3a Ifthe DDRAW DLL file does not exist in the Windows System folder DirectX is probably not installed on your computer DirectX 6 1 and above include a useful utility the DirectX Diagnostic Tool In Windows 98 you can launch this utility from the System Information program in the System Tools menu folder under Acces sories You can also launch DirectX Diagnostic by clicking Start selecting Run and typing dxdiag in the text box This tool reports detailed information about the DirectX components and drivers installed on your system It lets you test functionality diagnose problems and changes to your system configuration to work best Replacing Updating a Video Adapter Whether you re building a new PC from scratch upgrading your system or repla
75. icker for a few moments while the settings are being changed If the display becomes garbled or unusable simply wait and Windows will restore your original settings 6 Click Yes when you re prompted to keep this setting then click OK 1562 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS You see wavy lines in the monitor s display This is known to occur under Windows 98 with monitors such as the MAG DX 1795 This problem can occur if your video adapter is configured for 1600x1200 screen resolution and the Automatically detect Plug amp Play moni tors check box is selected on the Monitor tab in Display Properties To correct this problem manually install your monitor in Display Properties Click Start highlight Settings then click Control Panel Double click the Display icon Click the Settings tab then click Advanced On the Monitor tab click the Automatically detect Plug amp Play monitors check box to clear it then click Change A ND 5 Click Next click Display a list of all the drivers in a specific location so you can select the driver you want then click Next 6 Click Show All Hardware 7 Inthe Manufacturers box click MAG Technology Co Ltd then click MAG DX 1795 in the Models box 8 Click Next then follow the instructions on your screen to finish installing the monitor When returning to Windows from a DOS application the Windows screen splits from top to bott
76. icon Integrated Systems Silicon Integrated Systems Silicon Integrated Systems Silicon Integrated Systems Silicon Integrated Systems S MOS Trident Microsystems Trident Microsystems Trident Microsystems Trident Microsystems Trident Microsystems Trident Microsystems Trident Microsystems Trident Microsystems Trident Microsystems Trident Microsystems Trident Microsystems Tseng Labs Inc Tseng Labs Inc Tseng Labs Inc Tseng Labs Inc Tseng Labs Inc Tseng Labs Inc Tseng Labs Inc UMC UMC UMC Weitek Weitek Western Digital Paradise Western Digital Paradise Western Digital Paradise Western Digital SiS6205 http www sis com tw products multimedia him SiS6215 SiS6225 SiS6326 SiS6326AGP SiS6326DVD SiS300 301 SPC1500 http www smos com TGUI9420 30 http www tridentmicro com TGUI9440AGi TGUI9660 968x TVGA8900CL TVGA9000 TVGA9200Cxr TVGA9400CXi TVGA8900C 3DImage 975 3DImage 985 Blade 3D ET4000 W32 ET4000 W321 ET4000 W32p ET4000AX ET6000 VIPeR VPR6000 UMC 86C408 UMC 86C418 UMC 8710 P9000 P9100 WD90C30 hitp www wdc com WD90C31 WD90C33 RocketCHIP VIDEO SPEED FACTORS There is no one element that defines the performance of an accelerator board Overall performance is actu ally a combination of five major factors the video accelerator chip s a k a the chipset the video RAM the video BIOS drivers the RAMDAC and the expansion bu
77. ill not work under Windows unless the system s PCI SCSI devices are disconnected This type of problem occurs only on certain combinations of PCI system hardware For example this type of symptom has been documented using Phoenix BIOS 4 04 and a UMC8810P AIO motherboard on systems with an NCR SCSI controller and SCSI devices You can often correct such problems by correcting the Advanced System Setup in CMOS Start the CMOS Setup go to the Advanced System Setup and select PCI Devices Set up the PCI slot for the SCSI controller as IRQ9 and LEVEL edge select The slot for the video board should have the IRQ set to NONE and LEVEL edge select Change the Base Memory Address from 0080000000 to 008 1000000 There are boot problems when a new video board is installed Typical symptoms include no video or eight beeps when the system is turned on This problem is usually the result of an outdated system BIOS that is not capable of detecting the particular video chipset in use the BIOS interprets this condition as meaning that there is no video board in the system and an error is generated accordingly Contact the motherboard manufacturer or PC maker for an updated system BIOS Most BIOS versions dated after the fall of 1994 should be able to detect most modern video chipsets 1566 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS There are boot problems when a PCI video board is installed There are two common problems that account for this First the syst
78. in use today PC bus interface Connector to monitor Graphics accelerator or co processor RAMDAC FIGURE 43 8 Block diagram of a video accelerator board 1524 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS TABLE 43 2 LISTING OF POPULAR 2D AND 3D VIDEO CHIPSETS MANUFACTURER PRODUCT 3dfx VSA 100 Chip http www 3dfx com 3dfx Voodoo Series Voodoo Rush to Voodoo 5 3dfx Velocity Series 100 200 3DLabs Permedia http www 3dlabs com products index html 3DLabs GLINT 300SX 3DLabs Oxygen VX1 GVX1 GMX ACX Acer Labs ALI M3145 http www acerlabs com Acer Labs ALI CAT 32 64 Alliance Semiconductor ProMotion 3210 http www alsc com Alliance Semiconductor ProMotion 6410 Alliance Semiconductor ProMotion 6422 Alliance Semiconductor ProMotion AT24 ARK Logic ARK1000PV ARK Logic ARK2000PV Artist Graphics 3GA Graphics Processor hitp www artgraphics com Artist Graphics Artist 3GA Artist Graphics Artist GPX ATl 264VT http www ati com na pages products pc pc_index html ATI 3D RAGE ATI Mach32 ATI Mach64 ATI Mach64CT ATI Mach8 ATI 3D XPRESSION ATI XPERT 98 99 128 2000 At Play At Work etc ATI 3D CHARGER ATI All In Wonder Pro 128 128 Pro ATI RAGE Magnum Fury FuryPro Fury MAXX Avance Logic ALG 2032 http www avance com Avance Logic ALG 2064 Avance Logic ALG 2302 Avance Logic ALG 2308 Avance Logic ALG 2364 Avance Logic ALG 2401 Avance
79. isabling that also If the video system requires the use of an interrupt make sure that the IRQ is not being used by another device If the user manual for your video card lists any special settings for your CMOS Setup verify that you ve made the appropriate changes M Compatibility Check the video adapter maker s and motherboard maker s web site for any known compatibility issues Current video adapters may have minimum power requirements or use some features not supported by the motherboard s chipset This type of checking should be done before pur chasing a video adapter for an upgrade TROUBLESHOOTING VIDEO ADAPTERS 1551 MULTIPLE DISPLAY SUPPORT GUIDE Traditionally only one video adapter is allowed on the system but Windows 98 seeks to extend the desktop by supporting the use of more than one video adapter This capability allows more open windows and thus provides more information to the user at any given time However multiple display or multi monitor support is far from perfect and it must be used with the right combination of system BIOS video adapter chipsets and Windows 98 SE This part of the chapter highlights some of the key hardware requirements and issues common to multi monitor operation Video Adapters All of the video adapters used in a computer with multi monitor support must be Peripheral Component Interconnect PCI or Accelerated Graphics Port AGP devices using the multi monitor comp
80. iver is missing installed improperly or corrupt Reinstall the MPEG playback driver s for your particular video board and make sure to use the latest version If problems per sist check for the driver under the WIN INI or SYSTEM_INI file and see that there is only ONE load ref erence to the particular driver s repeated references can cause conflicts or other loading problems Similar drivers other MPEG drivers for example can also cause conflicts so verify that the only drivers being loaded are the ones used by your current video adapter and or playback software QAR EZI On video boards with TV tuners the TV window is blurry or fuzzy at 1024x768 or higher resolutions This symptom is particularly noted with the Diamond DVV1100 Unfortunately it is usually the result of limited bandwidth of the particular video board specifically of the TROUBLESHOOTING VIDEO ADAPTERS 1567 video chipset The only real option is to reduce the resolution to 800x600 or 640x480 when running the TV and to lower the refresh rate to 60Hz Contact your video board s manufacturer there may be an RMA or other replacement upgrade program that might be available to correct the issue On video boards with TV tuners the reception does not appear as good as that of an ordinary TV This problem has been noted in conjunction with Matrox Media TV boards and is usually due to the local cable company using the HRC carrier frequency instead of the standard carrier fr
81. liant dis play drivers that are included with Windows 98 Industry Standard Architecture Extended Industry Stan dard Architecture ISA EISA display adapters are specifically not supported Keep in mind that the video adapters installed in your computer do not have to be identical Each video adapter and monitor combina tion is separately enumerated by Windows 98 and can be configured to use different screen resolutions and color depths For example the primary display can be set to 1024x768x256 and the secondary dis play can be set to 800x600x32K Video Chipsets Drivers Any combination of the following supported PCI based video adapters can be used for multi monitor operation The list below will serve as primary and secondary adapters but only the list below may be used for secondary video adapters The drivers in Table 43 9 are supported by Microsoft and are included on the Windows 98 CD The basic Permedia chipsets cannot be used on multi monitor platforms but the Permedia NT and Permedia 2 can TABLE 43 9 VIDEO CHIPSETS DRIVERS SUITABLE FOR MULTI MONITOR OPERATION ATI Mach 64 GX GX GXD VT ATIM64 DRV ATI Graphics Pro Turbo PCI ATI Graphics Xpression ATI WinTurbo ATI Rage Il I ATI_M64 DRV ATI All In Wonder ATI 3D Xpression ATI 3D Xpression ATI 3D Xpression ATI Rage Pro AGP and PCI ATIR3 DRV ATI Xpert Work 4 and 8 MB ATI Xpert Play 4 and 8 MB ATI All In Wonder Pro S3 765 Trio64V S3MM DRV S3 Trio64V2
82. lmost always derived from the motherboard s Front Side Bus FSB clock When motherboards only offered a 66MHz clock this arrangement was not a problem for AGP since the FSB clock and AGP clock were basically the same thing However when motherboards went to 100MHZ and 133MHz and faster the AGP bus needed to be derived from the FSB In many cases the AGP clock is set from a motherboard jumper or through an entry in the CMOS Setup Yov ll generally find these settings denoted as the AGP Ratio and you can usu ally select 1 1 2 3 and 1 2 depending on the FSB speeds available You can see an example of how this setting is used below MB Ifthe FSB is 66MHz set the AGP Ratio to 1 1 and the AGP clock will be 66MHz M Ifthe FSB is 100MHPZ set the AGP Ratio to 2 3 and the AGP clock will be 66MHz M Ifthe FSB is 133MHz set the AGP Ratio to 1 2 and the AGP clock will be 66MHz You can also see the potential for overclocking B Ifthe FSB is 100MHZ setting the AGP Ratio to 1 1 will cause the AGP clock to be 100MHZ B Ifthe FSB is 133MHz setting the AGP Ratio to 2 3 will cause the AGP clock to be 88 7MHz 1548 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS As a rule it is unsafe to overclock the AGP bus especially if you re using AGP in the 2X or 4X data modes In most cases an overclocked AGP bus will result in unstable video and system operation In extreme cases the overclocked AGP card will be damaged AGP AND BIO
83. ncy monitors that are being pushed beyond their specifications The best course of action here is to simply reconfigure your software to use a compatible video mode or reduce the vertical refresh rate If doing that is an unsatisfactory solution you will have to upgrade to a monitor that will support the desired video mode If the monitor and video board are compatible there is a synchronization problem Try the monitor on aknown good PC If the monitor also fails on a known good PC try the known good monitor on the origi nal PC If the known good monitor works on the suspect PC the sync circuits in your original monitor have almost certainly failed If the suspect monitor works on a known good PC the trouble is likely in the original video adapter Try replacing the video adapter An error message appears on system startup indicating an invalid system configuration The system CMOS backup battery has probably failed and the video type may have defaulted to EGA or MCA instead of VGA resulting in the error This is typically a symptom that occurs in older systems If you enter your system setup either through a BIOS routine or through a disk based setup utility and examine each entry you will probably find that all entries have returned toa default setting including the video system setting Your best course is to replace the CMOS backup bat tery and enter each configuration setting again hopefully you have recorded each setting on paper alre
84. ns DirectInput works directly with device drivers bypassing the Windows message system resulting in faster and more responsive access to input devices DirectInput also supports force feedback devices Force feedback devices respond to an application with physical effects such as kick back when a trigger is fired vibration and resistance Force feedback devices make many game and entertainment experiences much more realistic and engaging DirectInput also supports the Universal Serial Bus for access to USB input devices MORE ON DIRECT3D Direct3D is a drawing interface for 3D hardware Using DirectDraw as a base Direct3D actually draws and renders the 3D scenes You can use Direct3D in either immediate mode or retained mode The Direct3D immediate mode was developed as a low level 3D API and is ideal for developers who need to port games and other high performance multimedia applications to the Microsoft Windows operating system It is a device independent way for applications to communicate with accelerator hardware at a low level By contrast retained mode is a high level 3D application programmer interface API for pro UNDERSTANDING DIRECTX 1539 grammers who require rapid development or who want the support for hierarchies and animations Direct3D retained mode is built on top of immediate mode The three components of the Direct3D device are the transform formulas describing how to convert a coordinate in 3D space int
85. nstead of the tradi tional 8 bit 256 color IMPROVING 3D PERFORMANCE THROUGH HARDWARE A 3D graphics accelerator improves 3D performance by relieving the host CPU of many of the computa tion intensive tasks needed to render a scene In most cases these tasks are performed by graphics proces sors on the 3D video accelerator itself Today s 3D graphics accelerators are capable of an astonishing array of features some of which are highlighted below Perspective correct texture mapping In real life objects have details that allow us to recog nize them For example an object made of wood is granular while steel is smooth and shimmering In 3D applications this detail is called texture Applying two dimensional texture images to 3D objects or scenes make them appear more realistic In the real world our perspective relative to an object changes as our position changes For example when you are walking along the side of a house the house will have a different perspective which each step In order to create this experience in a 3D application texture maps must be corrected to fit the changing perspective If the texture mapping is not perspective correct the image will be visually incorrect and filled with artifacts from previous frames While older 3D graphics accelerators only provided non perspective correct texture mapping in hardware many of the newest 3D graphics engines offer perspective correct textures at full rendering s
86. o 2D display coordinates the state variables defining the styles for drawing operations and the draw engine actu ally generating the object MORE ON DIRECTPLAY Applications generally and games in particular can be more compelling if they involve other persons and the PC provides a versatile platform for connections over networks or the Internet Instead of forcing the developer to deal with the differences that each connection scheme represents DirectPlay provides well defined generalized communication capabilities DirectPlay is a software interface that simplifies an application s access to communication services A DirectPlay session is a communications channel between several machines Before an applica tion can start communicating with other machines it must join a session An application can do this in two ways it can identify all the existing sessions on a network and join one of them or it can create a new session and wait for other machines to join it Once the application has joined a session it can create a player and exchange messages with all the other players in the session Each session has one machine that is designated as the host The host is the owner of the session and is the only machine that can change the properties of the session The most essential entity within a DirectPlay session is a player A player represents a logical object within the session that can send and receive messages DirectPlay do
87. o be standard equipment for all new PCs sold then but SVGA boards have rapidly replaced VGA systems and most SVGA adapters offer full VGA support 8514 1987 The 8514 A video adapter is a high resolution system also developed for the PS 2 In addition to full sup port for MDA CGA EGA and VGA modes the 8514 A can display 256 colors at 640x480 and 1024x768 interlaced resolutions Unfortunately the 8514 A was a standard ahead of its time The lack of available software and the demise of the PS 2 line doomed the 8514 A to extinction before it could become an accepted standard The XGA standard rapidly became the PC standard for high resolu tion high color display systems on MicroChannel PC platforms SVGA Super Video Graphics Array Ever since VGA became the de facto standard for PC graphics there has been a strong demand from PC users to move beyond the 640x480x 16 limit imposed by conventional VGA to provide higher resolu tions and color depths As a result new generations of extended VGA or super VGA SVGA adapters have moved relentlessly into the PC market Unlike VGA which adhered to strict hardware configura tions there is no generally accepted standard on which to develop an SVGA board each manufacturer makes an SVGA board that supports a variety of different and not necessarily compatible video modes For example one manufacturer may produce an SVGA board capable of 1024x768x65K while another manufacturer m
88. o map textures onto a 3D object with perspective correction M Point sampling This is the most common way to map a texture on a given polygon Point sampling allows the 3D graphics engine to approximate the color value of a given pixel on the resulting texture map by replicating the value of the closest existing pixel on the source texture Point sampling pro vides very good results when used in conjunction with tile based MIP mapping and maintains high performance levels at a low cost M Filtering Some source textures may need a considerable amount of warping which may lead to a blocky appearance Some graphics accelerator manufacturers use a bilinear filtering technique to make the textures appear smoother In bilinear filtering four source texel values are read and their color values are then blended together based on proximity The resulting values will be used for the texel to be drawn While this technique is useful the resulting quality is not comparable to using high resolution source textures 3D graphics accelerators without support for palletized textures have 3D GRAPHICS ACCELERATOR ISSUES 1535 to scale down the textures to store them and apply filtering to map them onto polygons This process results in poor quality rendering M MIP mapping MIP mapping is another way to improve the quality of the 3D texture mapped object The more alterations made to a texture to fit an object the less it will resemble the source te
89. o mode and remove the video adapter from your Windows 98 Device Manager a ND oon o 10 Click Start highlight Settings click Control Panel then double click the Display icon Select the Settings tab Use the Colors drop down to select the color depth you need for instance 6 colors Move the Screen Area slider to a resolution of 640x480 Click on the Apply button to test the selections you have made then click OK to finalize the selections Return to the Settings tab and click on the Advanced button to open the adapter s Properties dialog Select the Adapter tab then click Change When the Update Device Driver wizard appears click Next On the next screen select Display a list of all the drivers in a specific location so you can select the driver you want then click Next Select Show all hardware then scroll to the top of the list under Manufacturers and select Standard display types then select Standard PCI Graphics Adapter VGA under Models and click Next 1542 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS 11 Windows will install the standard VGA display driver and prompt you to restart your system for the changes to take effect 12 You should go ahead and restart your system to verify that the standard VGA display driver loads properly When you restart the system the standard VGA display driver is activated for use with your current dis play card This should allow
90. o the 2D screen Triangles that are farther away from the viewer s viewpoint will be smaller then those triangles that are closer E Draw the triangles The triangles are then drawn to the screen using a variety of shading or texture mapping techniques This time intensive process completes the scene that you see and the entire pro cess must be repeated for every frame generated by the game or other application KEY 3D SPEED ISSUES Higher frame rates create realism and true to life atmosphere in 3D games Speed is the main factor in providing faster frame rates If the frame rate of a game is too slow the game becomes unplayable because the time needed to react to an action in the game will be far too long Consider playing a flight simulator if the display was updated only once or twice per second Frame rate is largely dependent on the speed of a graphics accelerator The speed of a 3D graphics engine is typically rated in terms of millions of texels textured pixels per second or Mtexels sec It is also frequently rated in polygons a k a triangles per second Current 3D graphics accelerators can provide several million texels per second For example the 3Dfx Voodoo3 AGP card can render 7 million triangles per second The speed of a 3D application is dependent on many tasks but the most daunting tasks are 3D geome try and rendering Geometry is the suite of calculations used to determine an object s position and color on the screen
91. oftware As a result all video adapters from EGA on use local BIOS ROM to hold the firmware needed by the particular display controller Current PC architecture allocates about 128KB of space from C0000h to DFFFFh within the upper mem ory area for devices with expansion ROMs such as hard drive controllers and video adapters Mother board BIOS works in conjunction with the video BIOS which is detected during the POST Reviewing Video Display Hardware The early days of PC development left users with a simple choice between monochrome or color graphics all video adapters support text modes In the years that followed however the proliferation of video adapters have brought an array of video modes and standards that you should be familiar with before upgrading a PC or attempting to troubleshoot a video system This part of the chapter explains each of the video standards that have been developed in the last 20 years and shows you the video modes that each standard offers Table 43 1 provides a comprehensive listing of the standard hardware and software sup ported video modes for a 3Dfx Voodoo3 video accelerator All of the display modes shown are notnecessarily supported by a monitors or software Check the capabilities of your monitor and the requirements of your software before choosing a given display mode or refresh rate MDA Monochrome Display Adapter 1981 The Monochrome Display Adapter or MDA is the oldest conventional
92. om This is a DOS problem that is seen under Windows that indi cates an obsolete or corrupted video driver for example using a Windows 3 0 video driver under Win dows 3 1 chances are that the video adapter is running just fine Make sure that the proper DOS grabber file is installed and specified in the SYSTEM_INI file Check with the video board manufac turer to obtain the latest assortment of drivers and grabber files Try reinstalling the drivers from their master disk If you do not have current drivers available try switching to the generic VGA driver The system hangs up during initialization some characters may be missing from the display or the screen colors may be incorrect These are classic symp toms of a hardware conflict between the video adapter and one or more cards in the system or an area of memory Some video boards use an area of upper memory that is larger than the classical video area For example the Impact SVGA board imposes itself on the entire address range between A0000h and DFFFFh In this kind of situation any other device using an address in this range will conflict with the video board A conflict may occur when the video board is first installed or the board may work fine until another device is added or modified Resolving a hardware conflict basically means that something has to give one of the conflicting ele ments IRQ lines DMA channels or I O addresses must be adjusted to use unique system
93. ordi nary cookie sheet between the unshielded monitor and any monitors it interferes with You may also choose to replace the unshielded monitor with a shielded model You cannot drag a windows from one monitor to another under Windows 98 SE This problem can occur if the window you re trying to drag is maximized or your monitors are not positioned correctly To work around this issue restore the window to its previous size before you drag it to a different monitor To do this simply click the Restore button the middle button in 1560 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS the upper right corner of a window You should also verify your monitor s position Click Start click Help click the Index tab type multiple display support and then double click the arranging monitors topic for detailed information A basic Permedia video adapter cannot currently be used as your primary video adapter this excludes the Permedia NT and Permedia 2 You notice a black screen when you run a program requiring DirectX under Windows 95 98 When you run a DirectX based program your monitor may dis play a black screen or may display only wavy lines on a black background This fault can occur if the DirectX based program changes the default refresh rate that your display adapter uses with the monitor Change the refresh rate to an acceptable level for your monitor and selected resolution for example 60Hz or 72Hz 1 Click Star
94. peed Lighting For greater realism in a scene lighting is applied to objects to accentuate curves or create ambiance such as shadows Lighting effects are limited in software otherwise the frame rate would be degraded A key advantage of performing hardware based 3D rendering is the ability to apply lighting effects to polygons while maintaining full rendering speed Current adapters offer the ability to support up to eight hardware based light sources Texture transparency The technique of texture transparency is similar to chroma keying in video This technique draws one image on top of another while giving the appearance that the images fit there naturally Mapping complicated objects in a 3D scene such as trees is a challenge for software developers They must be able to map the tree on a transparent polygon so that the background of the scene will be shown through the branches Objects like trees may not be essential but they significantly improve the overall realism of a scene Without texture transparency these objects are typically left out or simplified New 3D graphics chips support texture transparency in hardware allowing developers to add a higher level of detail while maintaining graphics performance 1534 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS Hardware z buffering The use of a z buffer or depth buffer is necessary when two objects are intersecting each other The z buffer determines which portions o
95. pter s resources are superior to the host system s components AGP has 32 multiplexed address and data lines There are eight additional lines for sideband address ing These eight extra sideband address lines allow the graphics controller to issue new address and com mand data for read write requests simultaneously while data continues to move from previous requests on the main 32 data address lines An additional AGP feature known as Fast Write enables the CPU to write directly to the graphics card s frame buffer without going through system memory Fast Write is reported to be up to 30 percent faster than standard AGP 4X and 2D as well as 3D applications are supposed to ben efit from AGP 4X Fast Write Fast Write also requires chipset support which currently means an Intel 1820 chipset or newer but ALi and VIA should soon introduce chipsets with Fast Write support Intel designed the AGP specifications for its Pentium Pro and newer CPUs so it does not produce any chipsets to support both AGP and Socket 7 processors such as the AMD or Cyrix CPUs If you want to take advantage of AGP performance using a Socket 7 processor you will need to use a Super 7 motherboard with an AGP compliant chipset from ALi or VIA 3D Graphics Accelerator Issues Technically speaking 3D graphics is the graphical representation of a scene or object along three axes of reference height width and depth to make the scene appear more realistic This technique
96. references You can download it from hitp www 3dfx com view_io asp ID 96 Always make a complete backup of your Registry to a bootable floppy disk before making any changes to the system Registry 1 Click Start select Run then type regedit 2 Locate the HKEY_LOCAL_MACHINE Enum PCI key and delete the VEN_121A amp DEV folder 3 Locate the HKEY_LOCAL_MACHINE Software key and delete the 3Dfx Interactive folder Locate the HKEY_LOCAL_MACHINE Software Diamond key and delete the Monster3D folder 5 Locate the HKEY LOCAL_MACHINE Software Microsoft Windows Current Ver sion ControlsFolder Display shellex Property Sheet Handlers key and delete any folders per taining to the original Voodoo card A 1570 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS 10 11 12 Save your changes to the Registry then use Windows Explorer to open the c windows inf other folder Delete any INF file pertaining to the Monster3D 3Dfx Interactive the Monster Fusion and so on Click Start select Find then choose Files and Folders Search for any references to glide and delete any file references that you find Search for files such as DD3DFX DRV DD3DFX16 DLL DD3DFX32 DLL and MM3DFXx and delete those files if you find them Search for the FXMEMMAP VXD file and delete it as well Finally search for SSTIINIT and delete it Restart the computer and reinstall the drivers for the new Monster Fusion devic
97. resources From atechnician s viewpoint it rarely matters which of the conflicting devices are changed but remem ber that system startup files device drivers and application settings may also have to change to reflect newly selected resources You may also be able to resolve some memory conflicts by adding the EXCLUDE switch to EMM386 EXE The video adapter manual will indicate when an EXCLUDE switch is necessary VAN ate EE Your system is generating DMA errors with a VGA board in the system and video BIOS shadowing disabled This is a fairly rare symptom that develops only on some older i486 systems and is usually due to an 8 bit VGA board in a system equipped with a slower TROUBLESHOOTING VIDEO ADAPTERS 1563 version of the 1486 CPU in the 25MHz range The 8 bit access takes so long that some DMA requests are ignored thus an error is generated If you find such a problem try enabling video ROM shadowing through the CMOS setup to allow faster access to video instructions Also you may try anewer revision of the 1486 CPU The system hangs up using a 16 bit VGA board and one or more 8 bit controllers This is typically a problem that arises when 8 bit and 16 bit ISA boards are used in the same system Due to the way that an ISA bus separates the 8 bit and 16 bit segments accessing an 8 bit board when there are 16 bit boards in the system may cause the CPU to falsely determine that itis accessing a 16 bit board When this occurs the
98. rom the PCI bus PCI device performance also benefits since video data transfers are no longer required The system BIOS chipset and operating system must all support AGP to take advantage of AGP s performance capabilities The only operating systems that fully support AGP at this time are Windows 98 and Windows 2000 Windows 95 OSR 2 1 has limited AGP support but any AGP perfor mance benefit will be limited DirectDraw part of DirectX is constantly being updated because it is responsible for controlling AGP s use of main system memory While PCI specifications limit data transfer rates to a bandwidth of 132MB sec the 32 bit 66MHz AGP bus has a base bandwidth of 264MB sec The AGP 2X specification supports a bandwidth of 533MB sec by transferring data on both the rising and falling edges of the 66MHz clock double clock ing and also implements more efficient data transfer modes The timing of data transfers is controlled by strobe signals rather than the standard method of clock cycles strobe signals are generated by the device sending the data either the PC or the AGP board Generating both the data and the strobe signals allows the sending device to precisely control the timing Separating the data transfer timing from the bus clock also allowed Intel to create an AGP 4X specification By increasing the number of strobe signals from three to six Intel defined a virtual clock speed of 264MHz 4 X 66 and this improvement again dou bl
99. s 98 Install the video adapter and monitor drivers as necessary then restart your computer if you re prompted to do so Click Start highlight Settings then click Control Panel Double click the Display icon then click the Settings tab In the Display box click the adapter you want to use and then click the Extend my Windows desktop onto this monitor check box to select it Click OK Multi Monitor Issues Multi monitor display technology is fairly well established under Windows 98 SE but there are situa tion s where problems will arise The easiest way to test your multi monitor setup is to start Paint or WordPad under Windows 98 When Paint or WordPad is not running in full screen mode try to drag the program from one monitor to the other If you can do that you l1 know that multi monitor support is work ing correctly If doing this presents problems try the tips below to help isolate the trouble Disable the secondary display adapter to confirm that your program works properly on the primary display adapter 1 Click Start highlight Settings click Control Panel then double click the Display icon 2 On the Settings tab click the secondary monitor icon 3 Click the Extend my Windows desktop onto this monitor check box to clear it then click OK Avoid programs that do not fully comply with multi monitor support M Programs or drivers that modify the GDI EXE file or the display driver E Programs that
100. s architecture By understanding how 1528 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS each of these factors relate to performance you can make the best recommendations for system upgrades or replacement boards Video accelerator Of course the video accelerator chip itself usually the graphics chipset being used is at the core of the accelerator board The type of chip that is fixed function graphics accelerator or graphics co processor loosely defines the board s capabilities All other factors being equal a board with a graphics accelerator will certainly perform better than a fixed function accelerator Companies like 3dfx ATI Advance Logic Chips amp Technologies Matrox NVidia S3 and Oak have developed many of the video accelerator chips in use today Many of the chips provide a 32 bit data bus though even newer designs are providing a 64 bit or 128 bit data bus and they sustain very high data rates but a data bottle neck across a 16 bit that is ISA expansion bus can seriously degrade the IC s effectiveness Therefore means you should match the recommended board to the particular system a state of the art graphics accelerator will not necessarily make your old i286 shine Video RAM Video adapters rely on RAM to hold image data and video accelerator boards are no exception While the current amount of video RAM typically varies from 8MB to 16MB some late mode video adapters offer as much as 64MB the amount of
101. s into a visual image Of course a monitor alone is not good for very much except perhaps as a conversation piece or a room heater The next logical question is where does the video signal come from All video signals displayed on a monitor are produced by a 1514 UNDERSTANDING CONVENTIONAL VIDEO ADAPTERS 1515 FIGURE 43 1 A typical video adapter card video adapter circuit Figure 43 1 The term adapter is often used because the PC is adapted to the par ticular monitor through this circuit In most cases the video adapter is an expansion board that plugs into the PC s available bus slots It is the video adapter that converts raw data from the PC into image data which is stored in the adapter s video memory The exact amount of memory available depends on the par ticular adapter and the video modes that the adapter is designed to support The earliest adapters offered as little as 256KB while the latest adapters provide 32MB or more The video adapter then translates the contents of video memory into corresponding video signals that drive a monitor The actual operations of a video adapter are certainly more involved than described above but you can begin to appreciate the critical role that the video adapter plays in a PC If a video adapter fails the monitor will display gibberish or nothing at all To complicate matters even further many current soft ware applications require small device drivers video drivers
102. s provide fast efficient video performance while minimizing the amount of overhead circuitry needed on a video adapter TEXT VS GRAPHICS Video RAM also plays a vital role since it is RAM that holds the image data to be displayed The video adapter can operate in two modes text and graphic In the text mode the DOS command line mode ASCII characters are stored in video RAM A character ROM character generator and shift register pro duce the pixel patterns that form ASCII screen characters The character ROM holds a pixel pattern for every possible ASCII character including letters numbers and punctuation The character generator converts ROM data into a sequence of pixel bits and transfers them to a shift register The shift register produces a bit stream At the same time an attribute decoder determines whether the defined ASCII char acter is to be displayed as blinking inverted high intensity standard text or a text color for color moni tors The signal generator is responsible for turning the ASCH serial bit stream from the shift register into the video and synchronization signals that actually drive the monitor The signal generator may produce either analog or TTL video signals depending on how the particular monitor is to be operated Today vir tually all color graphic monitors operate from analog video signals In the graphic mode the Windows 98 desktop video RAM locations will contain the color gray scale inform
103. ssign IRQ for PCI VGA see that it s set to enabled or auto If the video card is not assigned to a suitable IRQ and the system BIOS does not have an option to assign an IRQ you ll need to contact your motherboard manufacturer and check for a BIOS update After installing 3D accelerator drivers you find an error such as Invalid VxD dynamic link call from h3vddd 01 0000 4974 In virtually every case you re trying to use an AGP accelerator card under Windows 95 OSR2 without having the proper USB support update installed The file USBSUPP EXE can be found on your Windows 95 CD if the CD is labeled With USB Support In addition to proper USB support this file also installs a new Virtual Memory Manager VMM that may be required for the AGP version of your accelerator card such as the Monster Fusion in Windows 95 If you do not have that file on your CD it can be downloaded at ftp ftp opti com pub chipsets system 861 usbsupp exe Upgrading the OS to Windows 98 SE should also correct this issue After upgrading from an older video card you can access higher colors but cannot use resolutions over 640x480 This type of issue is seen frequently when upgrading an older Stealth 64 card true color modes are accessible but resolutions above 640x480 are not This problem is almost always due to residual entries left in the Registry Start your Registry editor and check the following key HKEY_LOCAL_MACHINE Config 00
104. system will almost invariably crash Try removing any 8 bit boards from the system If the crashes cease you have probably nailed down the error Unfortunately the only real correction is to either remove the 8 bit board s or reconfigure the board s to use a higher area of memory You have trouble sizing or positioning the display or you see error messages such as Mode Not Supported or Insufficient Memory These kinds of errors may occur in newer or high end video boards if the board is not set up properly for the monitor it is being used with Most new video boards include an installation routine that records the monitor s maxi mum specifications such as resolution and refresh frequencies horizontal scanning frequencies and vertical scanning frequencies If such data is entered incorrectly or the monitor is changed certain screen modes may no longer work properly Check the video adapter s installation parameters and correct its setup if necessary You frequently encounter GPFs when using QuickTime for Windows 1 1 This is a notable problem with ATI Mach64 cards but it has been known to occur with other advanced video boards Often the problem can be corrected by making a change in the Windows S YSTEM INI file For the ATI Mach64 you must turn DeviceBitmaps off under the macx section As an alternative start the ATI FlexDesk type OPT doing this starts a hidden window then uncheck the DeviceBitmap entry The
105. t highlight Settings then click Control Panel 2 Double click the Display icon click the Settings tab then click Advanced 3 Click the Adapter tab and then click Adapter Default in the Refresh Rate box 4 Click OK when you re prompted to test the setting 5 Ifthe setting is displayed correctly click Yes to keep the setting If this doesn t work try reducing the hardware acceleration for the video adapter 1 Click Start highlight Settings then click Control Panel 2 Double click the System icon click the Performance tab then click Graphics 3 Move the Hardware Acceleration slider to one notch from the left the Basic setting click OK click Close and then click Yes when you re prompted to restart your computer You encounter a blank screen after installing a secondary video adapter for Windows 98 This trouble can occur if your computer has a built in video adapter and either your computer s BIOS does not provide support for multiple video adapters or the secondary video adapter is not supported for multiple display use To correct this behavior update your computer s BIOS and or obtain a different video adapter that s properly supported for Windows 98 multi monitor service You find that Riva 128 video adapters do not support multi monitor operation When you add a secondary video adapter to a system that uses a Riva 128 video adapter as the primary video adapter the computer may hang up This problem is almost al
106. ted to flaws in software in this case problems with the video driver or video toolkit that is installed with the particular video board For example Divide by Zero errors can be corrected with the Diamond Stealth 64 Video 2001 series by opening the InControl Tools package and changing a Center to Viewport selection to Center to Desk top Similarly the Maximize to Viewport selection should be changed to Maximize to Desktop Often upgrading the video driver or video support tools will eliminate this problem During MPEG playback the display flickers shows low refresh rates or appears to be in an interlaced mode This is not necessarily an error With some video boards such as the Diamond MVP1100 MPEG files cannot play correctly at high refresh rates typically over 72Hz When an MPEG file is played the driver will automatically switch to a 72Hz vertical refresh rate and may cause an unexpected change in display quality during playback After exiting from the MPEG player the original higher refresh rate will be restored If a vertical refresh rate lower than 72Hz was originally selected then the vertical refresh rate will not change during MPEG playback so you should see no difference in the display cD AN tel RE ya You receive an error such as There is an undetectable problem in loading the specified device driver when starting an MPEG player or other video tool In almost all cases the related dr
107. tes that there is not enough memory for playback or re sizing of the playback window This type of program is directly caused by a lack of system not video memory in the PC If your system uses SMARTDRV Windows 3 1x try reducing the mem ory used for caching Try unloading various unneeded programs from memory and consider disabling any RAM drives that may be active Finally consider adding more system RAM to the PC The video board refuses to accept a particular video mode Mode problems are most frequent when attempting to use unusual palette sizes such as 32k or 64k colors Try setting the video board to 256 colors If a higher color depth is needed it may be possible to run the video board in a palletized mode or gray scale mode by adding command line switches to the video driver Refer to the instructions that accompany the particular video board for detailed information You may also consider a video BIOS upgrade or try using an upgraded VESA driver such as UNIVBE 5 3 from SciTech Software Updated video drivers and or firmware may also be available to correct the problem The video system cannot lock memory using QEMM and linear video memory This is often a DOS problem with Motion Pixels video boards when using QEMM 7 04 and earlier versions The DPMI has a bug when accessing physical memory above the DPMI s host memory Upgrade the version of QEMM to 7 5 or later or play video under Windows instead The video system cannot lock memory
108. textures and performing the perspective calculations on both textures simultaneously This effect is very taxing on performance and costly to implement and only high end 3D graphics cards use true alpha blending in hardware Gouraud shading The technique of Gouraud shading or smooth shading draws smooth shadows across the face of an object This technique causes the viewer s eyes to perceive depth and curvature infor mation from the surface of the object Gouraud shading works by reading the color information at the three vertices of a triangle and interpolating the intensities in red green and blue smoothly between the three vertices Gouraud shading is the most popular algorithm used to draw 3D objects on a 2D screen Most objects can be rendered with amazing realism in 3D by using Gouraud shading and this feature is often available in 3D graphics accelerator hardware Double buffering Everyone has seen the old animation trick of drawing a cartoon character on the corner of a page of paper and altering the drawing slightly on following pages of paper When the sheaf of paper is complete and the pages flipped rapidly the cartoon character appears to move smoothly Dou ble buffered 3D animation on the PC works in the same way the next position of the character is being drawn before the page is flipped Viewing 3D animation without double buffering would be like looking at the animated cartoon as if the character were being redrawn with every
109. through try the standard VGA driver 1568 CHAPTER 43 VIDEO ADAPTERS AND ACCELERATORS Windows appears with a black box cursor and or icons that fail to appear on the screen In most cases the problem is caused by an incompatibility with the mother board s noncompliant PCI BIOS the motherboard s BIOS does not comply with the PCI backward com patibility requirement To overcome this problem set the video board s memory aperture manually by editing the SYSTEM INI file located in the WINDOWS directory For example when working with a Number Nine 9GXE find the 49GXE section of SYSTEM INI then add a command line such as APERTURE BASE 0x8800 or APERTURE BASE 31 Save the file and restart Windows The actual section for your particular video board may be different There are video problems or the system locks up while using an antivirus program This error occurs frequently when using memory resident virus checking Some video boards allow you to compensate for this by editing the SYSTEM INI file For the Number Nine 9GXE board find the 9GXE area in SYSTEM INI then set the Fast MMIO entry to OFF Remember to save the INI file and restart Windows The actual section for your particular video board may be differ ent As an alternative you could also disable or remove the antivirus program or check with the antivirus maker to see if there s a patch or update that might improve the program s compatibility An error indica
110. utes then turn it on again Conflicts between device drivers and terminate and stay resident TSR programs will upset the dis play and are particularly prone to crashing the computer The most effective way to check for conflicts is to create a backup copy of your system startup files CONFIG S YS and AUTOEXEC BAT From the root directory or directory that contains your startup files type copy autoexec bat autoexec xyz copy config sys config xyz The extension xyz implies that you can use any three letters but avoid using bak since many ASCII text editors create backup file with this extension Now that you have backup files go ahead and use an ASCII text editor such as the text editor included with DOS to REM out each driver or TSR command line Reboot the computer If the problem disappears use the ASCII text editor to re enable one REMed out command at a time Reboot and check the system after each command line is re enabled When the problem occurs again the last command you re enabled is the cause of the conflict Check that command line carefully There may be command line switches that you can add to the startup file that will load the driver or TSR without causing a conflict Oth erwise you would be wise to leave the offending command line REMed out If you encounter serious trouble in editing the startup files you can simply re copy the backup files to the working file names and start again Video drivers also play
111. video adapter available for the PC Text is available in an 80 column by 25 row format using 9x 14 pixel characters Being a text only sys tem MDA offered no graphics capability but it achieved popularity because of its relatively low cost good text display quality and integrated printer LPT port Figure 43 3 shows the video connector pinout for an MDA board The 9 pin monitor connection uses four active TTL signals intensity video horizon tal and vertical Video and intensity signals provide the on off and high low intensity information for each pixel The horizontal and vertical signals control the monitor s synchronization MDA boards have long been obsolete and the probability of encountering one is remote at best CGA Color Graphics Adapter 1981 The Color Graphics Adapter or CGA was the first to offer color text and graphics modes for the PC A 160x200 low resolution mode offered 16 colors but such low resolution received very little attention A 320x200 medium resolution graphics mode allowed finer graphics detail but with only four colors The highest resolution mode provides 640x200 at two colors usually black and one other color The relation ship between resolution and colors is important since a CGA frame requires 16KB of video RAM A resolu tion of 640x200 results in 128 000 pixels With 8 bits able to represent 8 pixels 128 000 8 16 000 bytes are adequate A resolution of 320x200 results in 64 000 pixels but with
112. video board will not boot up when used in a particular motherboard Generally speaking there are noted cases of hardware incompatibility between certain video boards and motherboards This condition usually causes a great deal of confusion because the video board may work just fine when tested in a different motherboard and other video boards may work well in the original motherboard the technician simply winds up chasing ghosts A noted example of this prob lem is the Boca Research VGAXL1 2 refusing to work in a Micronics 486DX2 66 motherboard The solution to this problem demands that U13 on the video board be a Texas Instruments TI 74F04 If U13 is a Motorola chip you ll need to send the board back for rework strange but true For general trouble shooting purposes if a certain video board and motherboard refuse to work together don t waste your time chasing ghosts contact both the video board maker and PC or motherboard maker and see if there are any reports of incompatibilities Diagnostics refuse to show all of the available video modes for a particular board even though all video RAM was properly detected or the board refuses to operate in some video modes When a video board does not respond to certain video modes usually the higher video modes it is usually because there is a conflict in the upper memory area anda memory range needs to be excluded If there is a memory manager at work such as QEMM 386MAX or 1564 CHAPTER
113. ways caused by an incom patible driver that is used by the Riva 128 video adapter consequently Riva 128 video adapters are not supported for use with the multiple display feature If you want to use multiple monitors you should use only video adapters that are known to work in a multiple monitor environment see Table 43 9 Replace the incompatible video adapter with a model that is compatible with multi monitor operation You have trouble using the ATI Rage Il PCI video card as a second video adapter When youtry the ATI Rage II PCI video adapter as a secondary display adapter under Windows 98 the secondary display adapter may not work properly if at all When you view the ATI Rage II PCI Properties dialog box in Device Manager you may see an error message such as TROUBLESHOOTING VIDEO ADAPTERS 1561 Multiple Display Support cannot start this device The area of memory normally used by video is in use by another program or device To enable Multiple Display Support remove EMM386 or other memory managers from CONFIG SYS and restart your computer Try adding an EMMExclude entry to the SYSTEM INI file 1 Open the SYSTEM INI file using any text editor such as Notepad 2 Add the following line to the 386enh section of the SYSTEM INI file mmexclude cO00 cfff 3 Save and then close the SYSTEM INI file 4 Restart your computer As an alternative try adding the exclusion to the EMM386 command line of your CONFIG S
114. xture One way to avoid this severe deviation from the original texture is to create three copies or MIP lev els of the same source texture each in different sizes MIP mapping can be implemented in three ways tile based MIP mapping per pixel MIP mapping and trilinear MIP mapping Fogging In order to maintain high performance developers created tricks to reduce the amount of rendering needed for a scene One of these tricks is called fogging It is mostly used in landscape scenes such as flight simulators Fogging allows the developer to hide the background of a scene behind a layer of fog mixing the textures color values with a monochrome color such as white Some newer 3D graphics chips support fogging in hardware Alpha blending Blending is a visual effect that mixes two textures on the same object Different lev els of blending can be implemented to create visual effects The simplest method is screen door or stip pling Only some pixels making up the object are rendered producing a see through effect For example the developer would decide that an object would be 50 percent transparent The graphics accel erator would then draw the background image and then write only every second pixel of the object This approach is easy to implement in hardware and delivers a reasonable quality at a low cost By contrast true alpha blending is a data intensive operation which involves reading the values of two source
115. ystems This is probably because the ALI based chipset requires an AGP driver in order to support AGP cards such as the V770 Ensure that the latest AGP driver from ALI has been installed from http www acerlabs com acerlabs drivers htm This patch is sup posed to work for both the Aladdin V chipset Super 7 as well as the Aladdin Pro II chipset for Pentium II systems also referred to as the BXPro Your Viper II Z200 video card doesn t work on an AMD Athlon based system This is almost always because the Athlon motherboard requires an AGP miniport driver Ensure that the latest AGP miniport driver has been installed from AMD http wwwl amd com athlon config Selecting a screen resolution over 640x480 causes an HP Pavilion system to reboot in the Safe Mode This is an HP BIOS problem HP has a main board BIOS upgrade for the Pavilion that should fix this The release notes for this new BIOS indicate that it fixes a problem with allocating IRQs to add in AGP adapters such as Nvidia based display adapters Check out the HP site at www hp com When booting to Windows you find a black screen or Windows indicates that the display adapter is not configured properly You may also find a yellow exclamation mark on the video card in your Device Manager In virtually all cases this problem occurs because the video card does not have an adequate IRQ assigned to it Boot into your system to the CMOS Setup and look for an option such as A

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