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56-514: The TMS9918 generates both grid-based character graphics (used to display text or background images) and sprites used for moving foreground objects. The key features of this chip are, as highlighted in a 1980 presentation by Karl Guttag (one of the designers): All of the ICs in this family are usually referred to by the TMS9918 name, sometimes with an 'A' postfix. The 'A' indicates a second version of

112-925: A clone called the T6950 and does not support the undocumented pattern / color table masking feature in graphics 2 mode. Later, Toshiba released the T7937A MSX-Engine with a built-in VDP and fixed the masking features. Both VDPs by Toshiba feature a slightly different palette than the Texas VDPs, with more vivid colors. The TMS9918 was the basis for the VDP chips in the Master System , Game Gear , and Mega Drive (Genesis) . They use additional display modes and registers, and added hardware scrolling capabilities and other advanced features. The Ricoh PPU chip in

168-580: A composite video palette. Colors were generated based on a combination of luminance and chrominance values for the TMS9918A and Y , R-Y and B-Y values are for the TMS9928A/9929A . The TMS9918 has a fixed 16-color palette , composed of 15 displayed colors and a "transparent" color. According to "Table 2.3 - Color Assignments" on the datasheet outputs levels are the following: Notes: Colors are merely illustrative, and were converted from

224-486: A gamma . The TMS9918 series chips had been designed to work with televisions and their CRTs had a gamma of 1.6 (remark: CRTs of Macintosh monitors had 1.8 and the CRTs of PC monitors had 2.2). Flat screens do not have gamma . For this reason the colors of the TMS9918 look somewhat pale here as you can see in the first table above. The below table uses the gamma-corrected values, which are (written in hexadecimal because this

280-571: A sprite is a two-dimensional bitmap that is integrated into a larger scene, most often in a 2D video game . Originally, the term sprite referred to fixed-sized objects composited together, by hardware, with a background. Use of the term has since become more general. Systems with hardware sprites include arcade video games of the 1970s and 1980s; game consoles including as the Atari VCS (1977), ColecoVision (1982), Famicom (1983), Genesis/Mega Drive (1988); and home computers such as

336-492: A handy chip to use in video "titlers" that could overlay text or graphics on video, while the '2' version does not. The original variants of the TMS9918 were depletion load NMOS and manufactured on a 4.5 μm process; it was one of the first depletion load NMOS chips Texas Instruments manufactured in contrast to the TMS9900 microprocessor which used the older enhancement load NMOS process that required three supply voltages. Due to

392-683: A hardware blitter and a customizable palette . The V9938 was designed for the MSX2 standard of computers, and later used in a third-party upgrade to the TI-99/4A : the Geneve 9640 "computer-on-a-card". The V9938, in turn, was succeeded by the V9958 , which added some additional high-colour modes and a horizontal two-page scroll register, these chips were used in the MSX2+/ turboR systems. Toshiba made

448-406: A number of screen modes that control the characteristics of the characters. There are four documented screen modes available in the TMS9918A (as mentioned before, the TMS9918 lacks mode Graphic 2): Technically, mode 2 is a character mode with a colorful character set. The screen is horizontally divided into three 256×64 pixel areas, each of which gets its own character set. By sequentially printing

504-417: A single row of pixels that are displayed on a scan line . To produce a two-dimensional shape, the sprite's single-row bitmap is altered by software from one scan line to the next. The 1979 Atari 400 and 800 home computers have similar, but more elaborate, circuitry capable of moving eight single-color objects per scan line: four 8-bit wide players and four 2-bit wide missiles . Each is the full height of

560-417: A single row of pixels that are displayed on a scan line . To produce a two-dimensional shape, the sprite's single-row bitmap is altered by software from one scan line to the next. The 1979 Atari 400 and 800 home computers have similar, but more elaborate, circuitry capable of moving eight single-color objects per scan line: four 8-bit wide players and four 2-bit wide missiles . Each is the full height of

616-402: A single scanline; any additional sprites' horizontal pixels are dropped. Sprites with a higher priority are drawn first. The VDP reports in a status register the number of the first dropped sprite. The CPU can get around this limitation by rotating sprite priorities so that a different set of sprites is drawn on every frame; instead of disappearing entirely, the sprites will flicker. This technique

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672-829: A solution to the problem: controlling each individual game element with a dedicated transistor . The rockets were essentially hardwired bitmaps that moved around the screen independently of the background, an important innovation for producing screen images more efficiently and providing the basis for sprite graphics. The earliest video games to represent player characters as human player sprites were arcade sports video games , beginning with Taito 's TV Basketball , released in April 1974 and licensed to Midway Manufacturing for release in North America. Designed by Tomohiro Nishikado , he wanted to move beyond simple Pong -style rectangles to character graphics, by rearranging

728-714: A solution to the problem: controlling each individual game element with a dedicated transistor . The rockets were essentially hardwired bitmaps that moved around the screen independently of the background, an important innovation for producing screen images more efficiently and providing the basis for sprite graphics. The earliest video games to represent player characters as human player sprites were arcade sports video games , beginning with Taito 's TV Basketball , released in April 1974 and licensed to Midway Manufacturing for release in North America. Designed by Tomohiro Nishikado , he wanted to move beyond simple Pong -style rectangles to character graphics, by rearranging

784-542: Is called OAM (Object Attribute Memory). This also applies to the Game Boy Advance and Nintendo DS . The use of sprites originated with arcade video games . Nolan Bushnell came up with the original concept when he developed the first arcade video game, Computer Space (1971). Technical limitations made it difficult to adapt the early mainframe game Spacewar! (1962), which performed an entire screen refresh for every little movement, so he came up with

840-476: Is called OAM (Object Attribute Memory). This also applies to the Game Boy Advance and Nintendo DS . The use of sprites originated with arcade video games . Nolan Bushnell came up with the original concept when he developed the first arcade video game, Computer Space (1971). Technical limitations made it difficult to adapt the early mainframe game Spacewar! (1962), which performed an entire screen refresh for every little movement, so he came up with

896-527: Is known as sprite multiplexing. Automatic sprite movement is not handled by the VDP. Instead, in practice, the CPU will pick up on the VDP's vertical interrupt - a standard VDP output, which is triggered automatically once every 50th or 60th of a second (depending on chip variant), at the start of the VBI ( vertical blanking interval ). The CPU then jumps to a sprite-handling routine in the software, which in turn tells

952-437: Is needed by Misplaced Pages's coding): Note: The used steps are: Round all values to two decimal places, then raise to the power of 1.6 for gamma correction and finally transform the range of values from 0...100 to 0...255. Texas Instruments' TMS9918A was succeeded by Yamaha's V9938 , which added additional bitmap modes, more colorful sprites , a vertical full-screen scroll register, vertical and horizontal offset registers,

1008-456: Is prepared for the video output device, such as a cathode-ray tube , without involvement of the main CPU and without the need for a full-screen frame buffer . Sprites can be positioned or altered by setting attributes used during the hardware composition process. The number of sprites which can be displayed per scan line is often lower than the total number of sprites a system supports. For example,

1064-405: Is to create a second copy of some or all of the display data to eliminate flickering and tearing, a technique known as double buffering . The CPU communicates with the VDP through an 8-bit bus . A pin controlled by the CPU separates this bus into two "ports", a control port and a data port. To write or read a byte of video memory, the CPU first has to write two bytes on the VDP's control port to

1120-439: Is used in the 1981 TI-99/4A . Sprites remained popular with the rise of 2.5D games (those which recreate a 3D game space from a 2D map) in the late 1980s and early 1990s. A technique called billboarding allows 2.5D games to keep onscreen sprites rotated toward the player view at all times. Some 2.5D games, such as 1993's Doom , allow the same entity to be represented by different sprites depending on its rotation relative to

1176-439: Is used in the 1981 TI-99/4A . Sprites remained popular with the rise of 2.5D games (those which recreate a 3D game space from a 2D map) in the late 1980s and early 1990s. A technique called billboarding allows 2.5D games to keep onscreen sprites rotated toward the player view at all times. Some 2.5D games, such as 1993's Doom , allow the same entity to be represented by different sprites depending on its rotation relative to

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1232-564: The Nintendo Entertainment System (Famicom) is also based on the TMS9918. Sprite (computer graphics) In computer graphics , a sprite is a two-dimensional bitmap that is integrated into a larger scene, most often in a 2D video game . Originally, the term sprite referred to fixed-sized objects composited together, by hardware, with a background. Use of the term has since become more general. Systems with hardware sprites include arcade video games of

1288-413: The Nintendo Entertainment System . According to Steve Golson from General Computer Corporation , the term "stamp" was used instead of "sprite" at the time. Signetics devised the first chips capable of generating sprite graphics (referred to as objects by Signetics) for home systems. The Signetics 2636 video processors were first used in the 1978 1292 Advanced Programmable Video System and later in

1344-413: The Nintendo Entertainment System . According to Steve Golson from General Computer Corporation , the term "stamp" was used instead of "sprite" at the time. Signetics devised the first chips capable of generating sprite graphics (referred to as objects by Signetics) for home systems. The Signetics 2636 video processors were first used in the 1978 1292 Advanced Programmable Video System and later in

1400-496: The TI-99/4 (1979), Atari 8-bit computers (1979), Commodore 64 (1982), MSX (1983), Amiga (1985), and X68000 (1987). Hardware varies in the number of sprites supported, the size and colors of each sprite, and special effects such as scaling or reporting pixel-precise overlap. Hardware composition of sprites occurs as each scan line is prepared for the video output device, such as a cathode-ray tube , without involvement of

1456-629: The '2' versions (including the TMS9929A) outputs analog Y luminance and R-Y and B-Y colour difference signals. The need for the latter was predominant in the 50 Hz world , including Europe, due to the different video signal standards PAL and SECAM . It was more cost-effective to output Y, R-Y and B-Y and encode them into PAL or SECAM in the RF modulator , than to try to have a different console for every different color standard. The '1' version also features an external composite video input which made it

1512-520: The 1970s and 1980s; game consoles including as the Atari VCS (1977), ColecoVision (1982), Famicom (1983), Genesis/Mega Drive (1988); and home computers such as the TI-99/4 (1979), Atari 8-bit computers (1979), Commodore 64 (1982), MSX (1983), Amiga (1985), and X68000 (1987). Hardware varies in the number of sprites supported, the size and colors of each sprite, and special effects such as scaling or reporting pixel-precise overlap. Hardware composition of sprites occurs as each scan line

1568-403: The 1979 Elektor TV Games Computer . The Atari VCS , released in 1977, has a hardware sprite implementation where five graphical objects can be moved independently of the game playfield. The term sprite was not in use at the time. The VCS's sprites are called movable objects in the programming manual, further identified as two players , two missiles , and one ball . These each consist of

1624-403: The 1979 Elektor TV Games Computer . The Atari VCS , released in 1977, has a hardware sprite implementation where five graphical objects can be moved independently of the game playfield. The term sprite was not in use at the time. The VCS's sprites are called movable objects in the programming manual, further identified as two players , two missiles , and one ball . These each consist of

1680-485: The 1979 Texas Instruments TMS9918 video display processor, this use of the word sprite came from David Ackley, a manager at TI. It was also used by Danny Hillis at Texas Instruments in the late 1970s. The term was derived from the fact that sprites "float" on top of the background image without overwriting it, much like a ghost or mythological sprite . Some hardware manufacturers used different terms, especially before sprite became common: Player/Missile Graphics

1736-547: The CPU. According to Karl Guttag, one of two engineers for the 1979 Texas Instruments TMS9918 video display processor, this use of the word sprite came from David Ackley, a manager at TI. It was also used by Danny Hillis at Texas Instruments in the late 1970s. The term was derived from the fact that sprites "float" on top of the background image without overwriting it, much like a ghost or mythological sprite . Some hardware manufacturers used different terms, especially before sprite became common: Player/Missile Graphics

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1792-503: The Texas Instruments TMS9918 chip supports 32 sprites, but only four can appear on the same scan line. The CPUs in modern computers, video game consoles, and mobile devices are fast enough that bitmaps can be drawn into a frame buffer without special hardware assistance. Beyond that, GPUs can render vast numbers of scaled, rotated, anti-aliased , partially translucent, very high resolution images in parallel with

1848-611: The VDC's internal address register . Next, the CPU performs the actual write or read on the VDP's data port. As a data byte is written or read, the TMS9918 automatically increments the internal address register. This auto-increment feature accelerates writes and reads of blocks of data. The control port is also used to access various internal registers. The TMS9918 has two separate and distinct graphics types: characters and sprites . Characters are typically used to create text or background images. They appear behind sprites. The TMS9918 has

1904-453: The VDP where to reposition the sprites. The sprite collision flag is set when non-zero pattern bits of two sprites coincide, even if either sprite has transparent colour. This is useful for triggering more advanced collision detection routines inside the software which can then determine the exact location of the collision and act upon it, as the VDP is itself incapable of reporting which two sprites have collided. The TMS9918 family chips used

1960-647: The YPrPb values (MS9928A/9929A) to sRGB taking into account Gamma correction . SMPTE C colorimetry was not taken into account - see the next section for alternate color conversions. In order to convert Y, R-Y and B-Y to RGB you need to consider how Y originated, namely: Thus you need to use the following formulas: But at first you need to spend attention to the fact that for all colors that have no chrominance - thus black, gray and white - R-Y and B-Y are not 0% but all have an offset of 47%. So you need to subtract this offset from all R-Y and B-Y values at first. Due to

2016-489: The characters 0 through 255 in all three areas, the program can simulate a graphics mode where each pixel can be set individually. However, the resulting framebuffer is non-linear. The program can also use three identical character sets, and then deal with the screen like a text mode with a colorful character set. Background patterns and sprites then consist of colorful characters. This was commonly used in games, because only 32×24 bytes would have to be moved to fill and scroll

2072-556: The chip which added new features, most prominently the addition of a bitmap mode (Graphic II). The TMS9918 was only used in the TI-99/4; the TI-99/4A and the other computers had the A version VDC. The TMS9918A and TMS9928A output a 60 Hz video signal , while the TMS9929A outputs 50 Hz. The difference between '1' and the '2' in 'TMS9918A' and 'TMS9928A' is that the '1' version outputs composite NTSC video, while

2128-544: The display—a long, thin strip. DMA from a table in memory automatically sets the graphics pattern registers for each scan line. Hardware registers control the horizontal position of each player and missile. Vertical motion is achieved by moving the bitmap data within a player or missile's strip. The feature was called player/missile graphics by Atari. Texas Instruments developed the TMS9918 chip with sprite support for its 1979 TI-99/4 home computer. An updated version

2184-490: The display—a long, thin strip. DMA from a table in memory automatically sets the graphics pattern registers for each scan line. Hardware registers control the horizontal position of each player and missile. Vertical motion is achieved by moving the bitmap data within a player or missile's strip. The feature was called player/missile graphics by Atari. Texas Instruments developed the TMS9918 chip with sprite support for its 1979 TI-99/4 home computer. An updated version

2240-442: The display. Additionally, it leaves more address space available to the CPU for other memory and memory-mapped hardware. Depending on the screen mode being used, not all of the video memory may be needed to generate the display. In these cases, the CPU may use the extra video memory for other purposes. For example, one use is as a scratch-pad for uncompressing graphics or sound data stored in cartridge ROM into. Another popular use

2296-642: The early 1980s, including Ms. Pac-Man . Movable Object Block , or MOB , was used in MOS Technology 's graphics chip literature. Commodore , the main user of MOS chips and the owner of MOS for most of the chip maker's lifetime, instead used the term sprite for the Commodore 64. OBJ s (short for objects ) is used in the developer manuals for the NES , Super NES , and Game Boy . The region of video RAM used to store sprite attributes and coordinates

TMS9918 - Misplaced Pages Continue

2352-474: The early 1980s, including Ms. Pac-Man . Movable Object Block , or MOB , was used in MOS Technology 's graphics chip literature. Commodore , the main user of MOS chips and the owner of MOS for most of the chip maker's lifetime, instead used the term sprite for the Commodore 64. OBJ s (short for objects ) is used in the developer manuals for the NES , Super NES , and Game Boy . The region of video RAM used to store sprite attributes and coordinates

2408-516: The eight 16K×1-bit chips the TMS99xx needs. Otherwise the chips are completely identical to the TMS9918A, TMS9928A and TMS9929A respectively. The VDP has 16K × 8 bits of external video memory. This memory is outside the address space of the CPU . Having a separate address space means that the CPU has to do more work to write or read this memory, but it also means that the VDC doesn't slow the CPU down when it periodically reads this memory to generate

2464-556: The entire screen. The challenge of using TMS9918 mode 2 was that every 8×1 pixel area could have only two colors, foreground and background. They could be freely picked out of the 16 color palette, but for each 8×1 area, only two colors could exist. When manipulating the screen in BASIC with the LINE command, one easily could exceed the maximum 2 colors per 8×1 area and end up with " color spill ". Texas Instruments originally only documented

2520-408: The fact that in practice this one step will never be done alone, it's no problem that some results will be negative: Now you can do the conversion to RGB. All results must be in the range from 0% to 100%: You might come to the conclusion that the erroneous value of 113% for R of color "light red" results out of a typo within the datasheet and there R-Y must not be greater than 80%. But if you measure

2576-941: The four modes listed above. However the bit that enables mode 2 is more interesting than initially let on. It is best described as a modifier bit for the other modes. Enabling it does three things: With this in mind, three additional modes are possible. Note that although genuine TMS9918A chips support these modes, clones and emulators may not. The TMS9918 does not have any scroll registers, so scrolling must be done by software. Furthermore, scrolling can only be done on character boundaries, not pixel by pixel. Sprites are typically used to create moving foreground objects. They appear in front of characters (tiles). Modes 1, 2, and 3 can render sprites. There can be up to 32 monochrome sprites of either 8×8 or 16×16 pixels on screen, each sprite with its own, single color. The illusion of multicolor sprites can be created by stacking multiple sprites on top of each other. There can be no more than 4 sprites on

2632-531: The large die size and relatively high internal speed, the TMS9918 ran warm enough to necessitate a heat sink; some devices such as the Taiwanese DINA console (a hybrid Colecovision/SG-1000) neglected to install sinks and suffered from malfunctions of the chip. By 1983 Texas Instruments had shrunk the die size to 3 μm which ran cooler and no longer required a sink; MSX machines and the Sega SG-1000 used

2688-400: The main CPU and without the need for a full-screen frame buffer . Sprites can be positioned or altered by setting attributes used during the hardware composition process. The number of sprites which can be displayed per scan line is often lower than the total number of sprites a system supports. For example, the Texas Instruments TMS9918 chip supports 32 sprites, but only four can appear on

2744-486: The newer 3 μm TMS9918 while most Colecovisions had the original 4.5 μm variant (the final run of the consoles produced in 1985 had the newer model TMS9918). A later variant of the TMS9918 series chips, the TMS9118 , TMS9128 , and TMS9129 , were released in the mid-late 1980s, but were never very popular. The function of one pin is changed, and the mapping of the video memory allows two 16K×4-bit chips to be used instead of

2800-414: The output signals of the chip with an oscilloscope , you'll find that all values in the table are correct. So the error is inside the chip and drives the red signal into saturation. For this reason this value is to be corrected to 100%. Furthermore, you need to consider that up to that time only cathode ray tubes have been available for computer monitors as well as for televisions, and that these CRTs had

2856-547: The rectangle shapes into objects that look like basketball players and basketball hoops . Ramtek released another sports video game in October 1974, Baseball , which similarly displayed human-like characters. The Namco Galaxian arcade system board , for the 1979 arcade game Galaxian , displays animated, multi-colored sprites over a scrolling background. It became the basis for Nintendo 's Radar Scope and Donkey Kong arcade hardware and home consoles such as

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2912-492: The rectangle shapes into objects that look like basketball players and basketball hoops . Ramtek released another sports video game in October 1974, Baseball , which similarly displayed human-like characters. The Namco Galaxian arcade system board , for the 1979 arcade game Galaxian , displays animated, multi-colored sprites over a scrolling background. It became the basis for Nintendo 's Radar Scope and Donkey Kong arcade hardware and home consoles such as

2968-400: The same scan line. The CPUs in modern computers, video game consoles, and mobile devices are fast enough that bitmaps can be drawn into a frame buffer without special hardware assistance. Beyond that, GPUs can render vast numbers of scaled, rotated, anti-aliased , partially translucent, very high resolution images in parallel with the CPU. According to Karl Guttag, one of two engineers for

3024-608: The viewer, furthering the illusion of 3D. Fully 3D games usually present world objects as 3D models , but sprites are supported in some 3D game engines , such as GoldSrc and Unreal , and may be billboarded or locked to fixed orientations. Sprites remain useful for small details, particle effects , and other applications where the lack of a third dimension is not a major detriment. These are base hardware specs and do not include additional programming techniques, such as using raster interrupts to repurpose sprites mid-frame. Sprite (computer graphics) In computer graphics ,

3080-459: Was a term used by Atari, Inc. for hardware sprites in the Atari 8-bit computers (1979) and Atari 5200 console (1982). The term reflects the use for both characters ("players") and smaller associated objects ("missiles") that share the same color. The earlier Atari Video Computer System and some Atari arcade games used player , missile , and ball . Stamp was used in some arcade hardware in

3136-408: Was a term used by Atari, Inc. for hardware sprites in the Atari 8-bit computers (1979) and Atari 5200 console (1982). The term reflects the use for both characters ("players") and smaller associated objects ("missiles") that share the same color. The earlier Atari Video Computer System and some Atari arcade games used player , missile , and ball . Stamp was used in some arcade hardware in

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