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RAID
A Redundant Array of Independent Disks is a set of drives connected to a special dual ported SCSI adapter that allows certain types of access optimization. A RAID 0 array stripes the data across multiple drives to decrease data latency. A RAID 1 array mirrors the data on multiple drives for increased data integrity. A RAID 5 array uses extra drives in a distributed manner to store parity information that can be used to apply data correction and recover any data in the event of any individual disk failure. This provides high reliability.
RAM
Random Access Memory. The memory that can be used by applications to perform necessary tasks while the computer is on. Memory chips that can hold easily changed information as long as there is an electric current running through them, but go blank when the electricity is cut off. The term "Random_Access" refers to the ability of a processor to immediately access any part of the memory. Many people confuse RAM and the hard disk. The RAM is temporary storage while the hard disk is semi-permanent storage. One way to understand the difference between the two is to relate RAM to short term memory and the hard disk to long term memory. Just as lots of memories are stored in your brain, lots of information is stored in a computer's hard drive. However, you can only actively think about and use a small portion of what you remember at any given time. This is similar to RAM. When a computer is using an application, it is loaded into RAM.
The computers primary working memory in which program instructions and data are stored and are accessible to the CPU. Information can be written to and read from RAM. The contents of RAM are lost when the computer is turned off.
RAMBUS DRAM
Rambus DRAM, a type of memory (DRAM) developed by Rambus, Inc. Whereas the fastest current memory technologies used by PCs (SDRAM) can deliver data at a maximum speed of about 100 MHz, RDRAM transfers data at up to 600 MHz.
In 1997, Intel announced that it would license the Rambus technology for use on its future motherboards, thus making it the likely de facto standard for memory architectures. However, a consortium of computer vendors is working on an alternative memory architecture called SyncLink DRAM (SLDRAM).
RDRAM is already being used in place of VRAM in some graphics accelerator boards, but it is not expected to be used for the main memory of PCs until 1998 or 1999. Intel and Rambus are also working a new version of RDRAM, called nDRAM, that will support data transfer speeds at up to 1,600 MHz.
RAM Disk
Also called a virtual drive. A portion of RAM that is used as if it were a disk drive. RAM drives are much faster than hard disks because your computer can read information faster from memory than from a hard disk. However, information on a RAM drive is lost when you turn off or reboot your computer.
RAM-Resident
A program remaining in memory after it has returned control of the computer back to the operating system. RAM-resident programs either wait or operate in the background while applications are active. Also called TSRs (Terminate and Stay Resident) in IBM PC and compatible computers.
Read-Only File
A file that you can read but cannot make changes to.
Read-Intensive
A process that requires a lot of reading of data from a device such as a hard disk.
Real CD Image
A Real CD Image can also be called a Physical ISO Image. This refers to a file that exactly duplicates how data will appear on the CD in ISO 9660 format. Since a Real CD Image contains the actual contents of the source, it requires the same amount of disc space as the CD-ROM disc to be created.
Red Book of CD
Physical format for audio CDs (a/k/a CD-DA) It was defined by Philips and SONY in 1980.
Removable Media
A computer data storage device in which the magnetic disk or tape is enclosed in a removable cassette or cartridge.
RF
Radio Frequency.
Ribbon cable
A group of wires arranged in rows that comprise a single flat cable resembling a ribbon. As known as flat-ribbon cable.
RISC Core
Some chips contain a RISC (Reduced Instruction Set Computer) processor, programmed through microcode scripts.
Rock Ridge
Extensions allowing UNIX stuff like long filenames and symlinks.
ROM
Read Only Memory. Memory from which information can be read but not changed. The contents of ROM are not erased when the computer is turned off.
A chip or chips with information- usually a program- written into them at the time of their manufacture. These chips cannot be re-written, hence "read-only." The contents of ROM remains even when the computer is turned off.
Round-Robin
A method of guaranteeing that number of devices will have an opportunity to be serviced. The round-robin method simply requires that every device is serviced in turn. After the last device is serviced the first one is serviced, and the process starts again.
RS-232
EIA standard for serial communications via hardwareEIA standard for serial communications via hardware.
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