Computer+Systems

A computer is an electric device that can perform tasks and calculations to provide logical information based on the instructions that have been given to it.


 * __Types of Computers -__ **
 * ** Desktop Computers- ** a computer designed for desktop use; usually comprises, at a minimum, a central processing unit, a monitor, and a keyboard as separate unit, connected by special cables.


 * ** Laptop Computers- ** a portable computer typically weighing less than six pounds that has a flat-panel display and miniature hard disk drives, and is powered by rechargeable batteries.


 * ** Handheld Computers- ** a pocket size computing device, typically having a display screen with touch input or a miniature keyboard.




 * **Supercomputers-** extremely powerful and technologically advanced computers used for solving complex and computationally intensive scientific or engineering problems.




 * **Embedded Computers-** a computer that cannot be programmed by the user because it is preprogrammed for a specific task and embedded within the equipment which it serves.
 * __ Hardware - __**


 * **Input Devices** - are computer devices that transport data into the computer.
 * **Keyboard** is an input device that allows you to get data into your computer. Keyboards can be wired or wireless, but they always communicate with a computer through game systems or USB connections that are found on the motherboard.




 * **Mouse** is a peripheral device that moves the cursor on your computer screen. The mouse is usually attached to a computer through a USB drive, although some are wireless, but need an adapter.




 * **Scanner** is a device that transfers hard copies of photos or documents to a computer. They are useful because they convert data into digital.




 * **Output Devices** - are parts on the computer that allow the user to see or hear the information that the computer compiles. These are examples of output devices:
 * **Speakers-** The speakers are external to the computer, that disable the lower fidelity built in speaker. It allows you to hear what the computer is compiling
 * **Projector-** A projector takes a video signal and projects the corresponding image on a projection screen using a lens system
 * **Monitor-** a part on the computer that displays images generated by the computer, without producing a permanent record.
 * **Printers -** are an external hardware device responsible for taking computer data and generating a hard copy of that data. They are one of the most used peripherals and are commonly used to print text, images, and/or photos. There are many different types of printers, such as Ink Jet printers, Laser printers, LED/LCD printers, Impact printers, and many more.
 * Two different types of printers are non impact and impact:
 * A **non impact** does not operate by striking a head against a ribbon. Examples of non impact printers are the laser and ink jet printers. A popular type of non impact printer is the Laser printer. This printer is any printer that places extremely small droplets of ink onto paper to create an image. The way this works is ink is emitted from nozzles while they pass over media. Print head scans the page in horizontal strips, using the printer’s motor assembly to move it from left to right, and back again.
 * An **impact printer** is one that strikes the media. Examples are the dot matrix, daisywheel, line printers, and chain printers. The chain printer uses type slugs linked together in a chain as its printing mechanism. The chain spins horizontally around a set of hammers. When the wanted character is in front of the selected part of the paper, the hammer hits the paper.


 * **Soft Copy and Hard Copy** - A soft copy is an electronic version of the document that is viewed on the monitor. A hard copy is a printed version. Soft copy can be in the form of e-mail or USB drive. Hard copy can be something that has been printed out, such as a word document.
 * **Storage Devices -**
 * **A floppy disk** is a data storage medium that is composed of a disk of thin, flexible ("floppy") magnetic storage medium encased in a square or rectangular plastic shell.
 * **A hard disk drive ** (often shortened as hard disk,( hard drive, or HDD) is a non-volatile storage device that stores digitally encoded data on rapidly rotating rigid (i.e. hard) platters with magnetic surfaces.
 * **A USB flash drive ** consists of flash memory data storage device integrated with a USB (Universal Serial Bus) 1.1 or 2.0 interface. USB flash drives are typically removable and rewritable, much smaller than a floppy disk, and most weigh less than 30 g (1 oz)
 * **CD-ROM** is a pre-pressed compact disc that contains [|data] accessible to, but not writable by, a computer for data storage and music playback, the 1985 [|“Yellow Book”] standard developed by [|Sony] and [|Philips] adapted the format to hold any form of [|binary data]
 * **The Zip drive ** is a medium-capacity removable [|disk storage] system, introduced by [|Iomega] in late 1994. Originally, Zip disks launched with capacities of only 100 [|MB], but later versions increased this to first 250 MB and then 750 MB.
 * **Digital Audio Tape** (DAT or R-DAT) is a signal recording and playback medium developed by [|Sony] and introduced in 1987. In appearance it is similar to a [|compact audio cassette], using 4 mm [|magnetic tape] enclosed in a protective shell, but is roughly half the size at 73 mm × 54 mm × 10.5 mm.


 * **Computer Processors -** A processing unit or CPU is a tiny chip, that is the complete engine of the computer, and they can perform many tasks such as the simplest to the most complicated math operations, moving data from one place to another and running the computer’s “tools”.
 * The processors chips primary function is translating electrical current into usable forms.
 * In private computers, the **CPU** is the “brains” of the computer, meaning that it controls all commands given to the computer. Using “bus lines” the processor chip sends and receives various information to different computer components.
 * The CPU (central processing unit) is the part of a computer controls the interpretation and execution of instructions.


 * __ Software - __**
 * **System Software -** controls the way computer parts work together.
 * **Operation System software -** manages the computers files and programs and acts as a graphic interference that translates mouse and keyboard actions into appropriate programming code. The two most up-to-date software’s are Windows 98 and Mac OS8.6.
 * Microsoft DOS- short for Microsoft disk operating system, MS-DOS is a non-graphical command line operating system created for IBM compatible computers that was first introduced by Microsoft.
 * UNIX- is an operating system that conforms to Unix standards, meaning the core operating system operates similarly to the original Unix operating system.
 * Mac OS8.6- The trademarked name for a series of graphical user interface based operating system developed by Apple Incorporated.
 * Microsoft Windows 98- A graphical operating system made by Microsoft it is a hybrid 16-bit/32-bit monolithic product with an MS-DOS based boot loader.
 * **Utility software** is a kind of system software designed to help analyze, configure, optimize, and maintain the computer. A single piece of utility software is usually called a utility or tool.
 * Security- Helps keep out intruders and protect your company’s assets form theft within the office walls.
 * Back up and restore- Allows you to back up all information from your computer to a hard disk and open at a later time.
 * Compression- Is encoding information while reducing the bandwidth or bits required.
 * Disk maintenance- This is where all the information gathered on your computer is located and when it gets too full it slows down.
 * **Application Software** - Sometimes referred to as "tool" software, it provides the tools needed to complete a task.
 * **Word Processing**-to create and print documents such as letters, memos, and reports Ex. Microsoft Word
 * **Spreadsheets**- analysis and reporting of statistical or numerical data to complete tasks such as preparing budgets, payroll, balance sheets, and profit and loss statements Ex. Microsoft Excel and Lotus 1-2-3
 * **Database Management**- allows the user to collect and organize data so its contents can easily be accessed, managed and updated by the user in a common environment Ex. Microsoft Access
 * **Presentation-** used to create slides that can be shown while an oral report is given Ex. Microsoft PowerPoint
 * **Graphics-** used to create charts, pictures, illustrations, drawings, and 3D images Ex. Paint, illustration/design, Photo-editing, Desktop Publishing
 * **Communications-** transmitting and receiving information from one computer to anotherEx. Text messaging and e-mailing
 * **Speech Recognition-** creates, edits, and format documents by specking into a microphone Ex. Dragon Naturally Speaking and Point and Click
 * __ Memory - __**Computer memory can be any device, such as a silicon chip or a hard disk used to store information.


 * There are two different types of computer memory, RAM and ROM:
 * **RAM** stands for random access memory, which is the physical memory of a computer. RAM can be accessed at anytime and in any order.
 * **ROM** stands for read only memory, which has data that has been prerecorded. This information cannot be removed.
 * Along with the ROM and RAM memory, there is a **cache**. This is a collection of data duplicating original values stored somewhere else in the computer. This cache operates as a temporary storage area where data can be stored for rapid access.