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RAM

Random Access Memory, the volatile memory used to temporarily store information for processing. This is the fastest type of memory for the computer, and the most expensive. There are several types of RAM.

S-RAM

Static RAM - the most expensive type of RAM found in memory units, some Printers, and in PCMCIA Type I Cards.

D-RAM

Dynamic Ram - most often seen as the expandable RAM used by the computer for memory.

Raster graphics displays (bitmapped displays)

Computer graphics in which an image is composed of an array of pixels arranged in rows and columns. Also called bitmap graphics.
Opposite= vector graphics.

Raster Images = Bit-mapped Images = Paint Graphic Images
A graphic of this type is defined as an array of x dots (pixels) wide and y dots high. A raster image might be created using a paint program, or by scanning a photograph or printed picture. These images do not scale well. If you increase the size of a raster, bumps that were previously too small to notice become large and chunky, and are called jaggies. Raster image files, especially in color, can be very large. An 24-bit color image scanned from a slide can take up 18 megabytes! But raster images are the only way to get photo-realistic graphics. Other effects, such as soft shadows, and realistic transparency, light refraction, and reflection can only be achieved using rasters. Examples of raster formats include MacPaint, GIF, TIFF, Targa, SunRaster, BMP, Photoshop, JPEG, PCX, Pixar, IMG, IFF, and PhotoCD. Programs that can create and edit raster images include MacPaint, Adobe Photoshop, Fractal Design Painter, Canvas, Corel Draw, SuperPaint, Dabbler, PC Paintbrush, RayDream Designer, and lots of others.

Resolution

1. The amount of digital information contained in a digitized image, usually expressed in dots per inch (dpi) or pixels per inch (ppi).
2. the maximum number of pixels that can be displayed on a monitor, expressed as (number of horizontal pixels) x (number of vertical pixels), i.e., 1024x768. The ratio of horizontal to vertical resolution is usually 4:3, the same as that of conventional television sets.

RGB

RGB stands for Red, Green, Blue and is the color language of computers. Computer monitors and digital cameras use these colors to create all the colors seen on the monitor and saved in files.

The RGB system matches colors by describing the amount of red, green, and blue light which composes them. The amount of each color is usually represented by a number from 0 to 255, with 0 meaning that the color is not present and 255 meaning that the maximum amount of the color possible is present.

Mixing some colors under this system is easy:
  pure red is represented as 255/0/0
  pure green is represented as 0/255/0
  pure blue is represented as 0/0/255

Secondary colors are similarly easy to represent, since all you have to do is combine the description of two primaries.

  Yellow is the combination of red and green or 255/255/0.

Neutral colors are represented by a balanced amount of each color. Black, of course, is 0/0/0 and white is 255/255/255.
  50% gray is represented by 127/127/127

To make tints, shades, and tones average the difference between the pure hue and the amount of gray that you're mixing into it.

Mixing blue with white
127/127/255
Mixing blue with black
0/0/127
Mixing blue with gray
64/64/191

ROM

Read Only Memory, ROM are chips in which the memory is permanently etched and used for delivering primary instructions to many computer peripherals and CPUs.