236 GlossaryRAM — random-access memory — The primary temporary storage area for programinstructions and data. Any information stored in RAM is lost when you shut down yourcomputer.readme file — A text file included with a software package or hardware product.Typically, readme files provide installation information and describe new productenhancements or corrections that have not yet been documented.read-only — Data and/or files you can view but cannot edit or delete. A file can haveread-only status if:• It resides on a physically write-protected floppy disk, CD, or DVD.• It is located on a network in a directory and the system administrator has assignedrights only to specific individuals.refresh rate — The frequency, measured in Hz, at which your screen's horizontal linesare recharged (sometimes also referred to as its vertical frequency). The higher therefresh rate, the less video flicker can be seen by the human eye.resolution — The sharpness and clarity of an image produced by a printer or displayedon a monitor. The higher the resolution, the sharper the image.RFI — radio frequency interference — Interference that is generated at typical radiofrequencies, in the range of 10 kHz to 100,000 MHz. Radio frequencies are at thelower end of the electromagnetic frequency spectrum and are more likely to haveinterference than the higher frequency radiations, such as infrared and light.ROM — read-only memory — Memory that stores data and programs that cannot bedeleted or written to by the computer. ROM, unlike RAM, retains its contents afteryou shut down your computer. Some programs essential to the operation of yourcomputer reside in ROM.RPM — revolutions per minute — The number of rotations that occur per minute.Hard drive speed is often measured in rpm.RTC — real time clock — Battery-powered clock on the system board that keeps thedate and time after you shut down the computer.RTCRST — real-time clock reset — A jumper on the system board of some computersthat can often be used for troubleshooting problems.SSAS — serial attached SCSI — A faster, serial version of the SCSI interface (asopposed to the original SCSI parallel architecture).SATA — serial ATA — A faster, serial version of the ATA (IDE) interface.
