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Video display controller
A video display controller (VDC), also called a display engine or display interface, is an integrated circuit which is the main component in a video-signal generator, a device responsible for the production of a TV video signal in a computing or game system. Some VDCs also generate an audio signal, but that is not their main function. VDCs were used in the home computers of the 1980s and also in some early video picture systems.
The VDC is the main component of the video signal generator logic, responsible for generating the timing of video signals such as the horizontal and vertical synchronization signals and the blanking interval signal. Sometimes other supporting chips were necessary to build a complete system, such as RAM to hold pixel data, ROM to hold character fonts, or some discrete logic such as shift registers.
Most often the VDC chip is completely integrated in the logic of the main computer system, (its video RAM appears in the memory map of the main CPU), but sometimes it functions as a coprocessor that can manipulate the video RAM contents independently.
The difference between a display controller, a graphics accelerator, and a video compression/decompression IC is huge, but, since all of this logic is usually found on the chip of a graphics processing unit and is usually not available separately to the end-customer, there is often much confusion about these very different functional blocks.
GPUs with hardware acceleration became popular during the 1990s, including the S3 ViRGE, the Matrox Mystique, and the Voodoo Graphics; though earlier examples such as the NEC μPD7220 had already existed for some time. VDCs often had special hardware for the creation of "sprites", a function that in more modern VDP chips is done with the "Bit Blitter" using the "Bit blit" function.
One example of a typical video display processor is the "VDP2 32-bit background and scroll plane video display processor" of the Sega Saturn. Another example is the Lisa (AGA) chip that was used for the improved graphics of the later generation Amiga computers.
That said, it is not completely clear when a "video chip" is a "video display controller" and when it is a "video display processor". For example, the TMS9918 is sometimes called a "video display controller" and sometimes a "video display processor". In general however a "video display processor" has some power to "process" the contents of the video RAM (filling an area of RAM for example), while a "video display controller" only controls the timing of the video synchronization signals and the access to the video RAM.
The graphics processing unit (GPU) goes one step further than the VDP and normally also supports 3D functionality. This is the kind of chip that is used in modern personal computers.
Hub AI
Video display controller AI simulator
(@Video display controller_simulator)
Video display controller
A video display controller (VDC), also called a display engine or display interface, is an integrated circuit which is the main component in a video-signal generator, a device responsible for the production of a TV video signal in a computing or game system. Some VDCs also generate an audio signal, but that is not their main function. VDCs were used in the home computers of the 1980s and also in some early video picture systems.
The VDC is the main component of the video signal generator logic, responsible for generating the timing of video signals such as the horizontal and vertical synchronization signals and the blanking interval signal. Sometimes other supporting chips were necessary to build a complete system, such as RAM to hold pixel data, ROM to hold character fonts, or some discrete logic such as shift registers.
Most often the VDC chip is completely integrated in the logic of the main computer system, (its video RAM appears in the memory map of the main CPU), but sometimes it functions as a coprocessor that can manipulate the video RAM contents independently.
The difference between a display controller, a graphics accelerator, and a video compression/decompression IC is huge, but, since all of this logic is usually found on the chip of a graphics processing unit and is usually not available separately to the end-customer, there is often much confusion about these very different functional blocks.
GPUs with hardware acceleration became popular during the 1990s, including the S3 ViRGE, the Matrox Mystique, and the Voodoo Graphics; though earlier examples such as the NEC μPD7220 had already existed for some time. VDCs often had special hardware for the creation of "sprites", a function that in more modern VDP chips is done with the "Bit Blitter" using the "Bit blit" function.
One example of a typical video display processor is the "VDP2 32-bit background and scroll plane video display processor" of the Sega Saturn. Another example is the Lisa (AGA) chip that was used for the improved graphics of the later generation Amiga computers.
That said, it is not completely clear when a "video chip" is a "video display controller" and when it is a "video display processor". For example, the TMS9918 is sometimes called a "video display controller" and sometimes a "video display processor". In general however a "video display processor" has some power to "process" the contents of the video RAM (filling an area of RAM for example), while a "video display controller" only controls the timing of the video synchronization signals and the access to the video RAM.
The graphics processing unit (GPU) goes one step further than the VDP and normally also supports 3D functionality. This is the kind of chip that is used in modern personal computers.