page_title: Composite artifact colors
hierarchical_section_title: Composite artifact colors
caption_attribution_description: English: CGA 80-column text display on RGB vs. Composite monitors.
context_page_description: Composite artifact colors is a designation commonly used to address several graphic modes of some 1970s and 1980s home computers.
  With some machines, when connected to an NTSC TV or monitor over composite video outputs, the video signal encoding allowed for extra colors to be displayed, by manipulating the pixel position on screen, not being limited by each machine's hardware color palette.
  This mode was used mainly for games, since it limited the display's horizontal resolution more than normal. It was mostly used on the IBM PC, TRS-80 Color Computer and Apple II computers, but also possible on Atari 8-bit.
  The limitations of composite video regarding horizontal resolution were also exploited on other systems. Adjacent pixel values got averaged horizontally, producing solid colors or generating transparency effects.
  On PAL displays this effect doesn't generate new colors, but rather a mix of adjacent horizontal pixel values. However, depending on the PAL system used, results will vary. If PAL M or PAL N are used color artifacts seen on NTSC might also be possible.
  If a higher resolution video connection is used, the graphics are displayed as dither patterns.
context_section_description: Composite artifact colors  is a designation commonly used to address several graphic modes of some 1970s and 1980s home computers. 
  With some machines, when connected to an NTSC TV or monitor over composite video outputs, the video signal encoding allowed for extra colors to be displayed, by manipulating the pixel position on screen, not being limited by each machine's hardware color palette (though, on modern TVs it might not work as well).
  This mode was used mainly for games, since it limited the display's horizontal resolution more than normal. It was mostly used on the IBM PC (with CGA graphics), TRS-80 Color Computer and Apple II computers, but also possible on Atari 8-bit.
  The limitations of composite video regarding horizontal resolution were also exploited on other systems.  Adjacent pixel values got averaged horizontally, producing solid colors or generating transparency effects.
  On PAL displays (or NTSC 4.43 ones) this effect doesn't generate new colors, but rather a mix of adjacent horizontal pixel values. However, depending on the PAL system used, results will vary. If PAL M or PAL N are used color artifacts seen on NTSC might also be possible. 
  If a higher resolution video connection is used, the graphics are displayed as dither patterns.
  Machines such as the ZX Spectrum or Mega Drive took advantage of this situation.
caption: CGA 80-column text on RGB (left) vs. composite monitor (right)
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