Dell Precision 490 Desktop User Manual

Also see for Precision Workstation 490: Quick reference guide Quick reference guide Quick guide Specifications

Contents

PIO — programmed input/output — A method of transferring data between two devices through the processor as part of the data path.pixel — A single point on a display screen. Pixels are arranged in rows and columns to create an image. A video resolution, such as 800 x 600, is expressed asthe number of pixels across by the number of pixels up and down.Plug-and-Play — The ability of the computer to automatically configure devices. Plug and Play provides automatic installation, configuration, and compatibilitywith existing hardware if the BIOS, operating system, and all devices are Plug and Play compliant.POST — power-on self-test — Diagnostics programs, loaded automatically by the BIOS, that perform basic tests on the major computer components, such asmemory, hard drives, and video. If no problems are detected during POST, the computer continues the start-up.processor — A computer chip that interprets and executes program instructions. Sometimes the processor is referred to as the CPU (central processing unit).program — Any software that processes data for you, including spreadsheet, word processor, database, and game packages. Programs require an operatingsystem to run.PS/2 — personal system/2 — A type of connector for attaching a PS/2-compatible keyboard, mouse, or keypad.PXE — pre-boot execution environment — A WfM (Wired for Management) standard that allows networked computers that do not have an operating system tobe configured and started remotely.RRAID — redundant array of independent disks — A method of providing data redundancy. Some common implementations of RAID include RAID 0, RAID 1,RAID 5, RAID 10, and RAID 50.RAM — random-access memory — The primary temporary storage area for program instructions and data. Any information stored in RAM is lost when you shutdown your computer.readme file — A text file included with a software package or hardware product. Typically, readme files provide installation information and describe newproduct enhancements 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 have read-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 assigned rights only to specific individuals.refresh rate — The frequency, measured in Hz, at which your screen's horizontal lines are recharged (sometimes also referred to as its vertical frequency). Thehigher the refresh 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 displayed on a monitor. The higher the resolution, the sharper the image.RFI — radio frequency interference — Interference that is generated at typical radio frequencies, in the range of 10 kHz to 100,000 MHz. Radio frequencies areat the lower end of the electromagnetic frequency spectrum and are more likely to have interference than the higher frequency radiations, such as infraredand light.ROM — read-only memory — Memory that stores data and programs that cannot be deleted or written to by the computer. ROM, unlike RAM, retains itscontents after you shut down your computer. Some programs essential to the operation of your computer 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 the date and time after you shut down the computer.RTCRST — real-time clock reset — A jumper on the system board of some computers that can often be used for troubleshooting problems.SSAS — serial attached SCSI — A faster, serial version of the SCSI interface (as opposed to the original SCSI parallel architecture).SATA — serial ATA — A faster, serial version of the ATA (IDE) interface.ScanDisk — A Microsoft utility that checks files, folders, and the hard disk's surface for errors. ScanDisk often runs when you restart the computer after it hasstopped responding.SCSI — small computer system interface — A high-speed interface that can be used to connect devices to a computer, such as hard drives, CD drives, printers,and scanners. The SCSI can connect many devices using a single controller. Each device is accessed by an individual ID number on the SCSI controller's bus.SDRAM — synchronous dynamic random-access memory — A type of DRAM that is synchronized with the optimal clock speed of the processor.serial connector — An I/O port often used to connect devices such as a handheld digital device or digital camera to your computer.Service Tag — A bar code label on your computer that identifies your computer when you access Dell Support at support.dell.com or when you call Dell forcustomer service or technical support.setup program — A program that is used to install and configure hardware and software. The setup.exe or install.exe program comes with most Windowssoftware packages. Setup program differs from system setup.shortcut — An icon that provides quick access to frequently used programs, files, folders, and drives. When you place a shortcut on your Windows desktopand double-click the icon, you can open its corresponding folder or file without having to find it first. Shortcut icons do not change the location of files. If youdelete a shortcut, the original file is not affected. Also, you can rename a shortcut icon.shutdown — The process of closing windows and exiting programs, exiting the operating system, and turning off your computer. You can lose data if you turn