http://www.gateway2000.com/support/custserv/glossary/r.htm (Amiga Plus Extra No. 5/97, 05/1997)

The s

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*RAID*		Redundant Array of Inexpensive Drives. Typically used on a network file server. A method of combining several relatively cheap hard disk drives to make one large drive.
*RAM*		Random Access Memory. Computer memory used to temporarily hold programs and data. RAM is stored in ICs that plug into the system board, or into an expansion card which in turn plugs into slots on the system board. There are two basic types of RAM chips: Static RAM (SRAM) and dynamic RAM (DRAM). SRAM chips are faster, but are also more expensive than DRAM.
RAM cache		A method of storing frequently-accessed data in static RAM that is much faster than the system's main memory, resulting in a significant increase in system speed.
RAMDAC		RAM Digital-to-Analog Converter. A chip on a video controller that converts the digital data in video memory into the analog voltages used by the monitor's electron guns. The chip also contains a section of RAM that contains a color look-up table.
random access		Able to read any location directly; without having to read sequentially to the location.
*RDRAM*		Rambus Dynamic Random Access Memory. A type of memory targeted at the video card market. It uses a proprietary RAM bus channel and boasts high data transfer rates (up to 500MBps sustained). It excels at such tasks as video streaming but lacks in the more intensive tasks like random access.
read-only		You can get the information, but you can't change it. For example, the contents of a ROM chip.
read/write head		The part of a disk drive that detects and writes bits on the disk.
reboot		To restart a computer, usually because of a crash. See boot.
record		In a database, the data from the same single instance of each field. For example, one person's name, address, and phone number. Compare field.
record locking		A procedure for allowing only one user at a time to be able to change a record.
recover		To return to normal after a minor crash.
recursive		Term used in programming to refer to a function that calls itself.
refresh cycle		A pulse of electricity necessary for dynamic circuitry to maintain its state.
refresh rate		The maximum number of frames that can be displayed on a monitor in a second, expressed in Hertz
registry		The registry is a storage location containing information about your current hardware configuration, installed software applications, settings and preferences of the current user, and associations between types of files and the applications that access their contents.
remote		Attached to another computer (or the other computer itself), but accessible in some way to the computer you are using.
repeat rate		How fast a character repeats itself on the screen when you hold down the key.
repeat delay		How long you have to hold down a key before the repeating starts.
resolution		How fine the detail is on a screen or printout. Screen resolution is measured in pixels across, pixels down, and number of colors. Printer resolution is measured in dpi (qv) or with vague terms like draft, letter quality, and near letter quality.
restore		To replace damaged data with undamaged data from a backup.
revert		To return to the last version of work that you saved. Any changes you made since that last save are lost.
RF		Radio Frequency. When someone runs the vacuum cleaner and it makes a lot of snow on the TV, the snow is caused by RF radiation. See shielding.
RGB		Red Green Blue. Refers to a type of color monitor in which the three color signals come in on separate lines. Compare composite.
ribbon cable		A cable in which all the wires are side by side, producing a flat, flexible cable. Frequently wire #1 is identified by a stripe on its insulation.
ring topology		A network whose nodes are connected in a continuous loop.
RISC		Reduced Instruction Set Computer. Refers to a microprocessor design that uses a relatively simple architecture, with fewer built-in commands than a CISC chip. The benefit is a significant increase in speed, enough to make up for not having as many instructions. Compare CISC.
RJ-11		A telephone jack with six possible connections. Often found on the back of US-manufactured modems or for connection to a leased line.
RJ-45		A serial connector that resembles a standard telephone connector except it has eight wires instead of four. RJ-45s are typically found on devices such as terminal servers that have many ports.
RLL		Run Length Limited. A way of recording data on a hard disk that requires about half the space, but more precise timing, than MFM.
ROM		Read-Only Memory. Computer memory used to permanently store parts of the computer's or expansion cardµs operating system. ROM chips can contain instructions and data. Informally means any storage which can be read but not changed. See Also BIOS.
root		See root directory.
root directory		The main directory on a hard disk. All other directories are subdirectories.
router		A network device that sends messages by the best route, especially over large networks.
routine		A program or part of a program that does one thing.

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