COMPUTING'2008

Peripheral Devices

2008-04-14T22:35:00.008+08:00

Input, Output and Communication with Peripheral Devices

Input Devices

Scanner

Optical Character Recognition (OCR)

Magnetic Ink Character Recognition (MICR)

Optical Mark Recognition (OMR)

Output Devices

Visual Display Unit

Laser Printer

Inkjet Printer

Dot matrix printer

Plotter

exercise : components of a computer system & modes of use

2008-03-13T09:13:00.003+08:00

1) define the terms

a. hardware

Computer hardware is the physical part of a computer, including the digital circuitry, as distinguished from the computer software that executes within the hardware. The hardware of a computer is infrequently changed, in comparison with software and hardware data, which are "soft" in the sense that they are readily created, modified or erased on the computer. Firmware is a special type of software that rarely, if ever, needs to be changed and so is stored on hardware devices such as read-only memory (ROM) where it is not readily changed (and is, therefore, "firm" rather than just "soft").

b. software

Computer software is a general term used to describe a collection of computer programs, procedures and documentation that perform some tasks on a computer system. The term includes application software such as word processors which perform productive tasks for users, system software such as operating systems, which interface with hardware to provide the necessary services for application software, and middleware which controls and co-ordinates distributed systems.

c. input device

An Input device is any piece of computer hardware equipment used to provide data and control signals to an information processing system (such as a computer). Input and output devices make up the hardware interface between a computer and the user or external world. Typical examples of input devices include keyboards and mice. However, there are others which provide many more degrees of freedom. In general, any sensor which monitors, scans for and accepts information from the external world can be considered an input device, whether or not the information is under the direct control of a user.

d. storage device

A device used to record and store data. The term usually refers to mass storage devices, such as hard disk and floppy disk.

e. output device

An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) to the outside world. In computing, input/output, or I/O, refers to the communication between an information processing system (such as a computer), and the outside world. Inputs are the signals or data sent to the system, and outputs are the signals or data sent by the system to the outside.

2) describe the purpose

a. input devices

a device that can be used to insert data into a computer or other computational device

b. storage devices

a device that preserves information for retrieval

c. output devices

electronic or electromechanical equipment connected to a computer and used to transfer data out of the computer in the form of text, images, sounds, or other media

3) define the types of software

a. operating system

Software designed to control the hardware of a specific data-processing system in order to allow users and application programs to make use of it.

Software designed to handle basic elements of computer operation, such as sending instructions to hardware devices like disk drives and computer screens, and allocating system resources such as memory to different software applications being run. Given uniformly designed operating systems that run on many different computers, developers of software do not need to concern themselves with these problems, and are provided with a standard platform for new programs.

b. user interface

a program that controls a display for the user (usually on a computer monitor) and that allows the user to interact with the system

c. translator

a program that translates one programming language into another

d. utilities

a program designed for general support of the processes of a computer; "a computer system provides utility programs to perform the tasks needed by most users"

e. programming languages

A programming language is an artificial language that can be used to control the behavior of a machine, particularly a computer. Programming languages, like natural languages, are defined by syntactic and semantic rules which describe their structure and meaning respectively. Many programming languages have some form of written specification of their syntax and semantics; some are defined only by an official implementation.

f. generic/common applications software

subclass of computer software that employs the capabilities of a computer directly and thoroughly to a task that the user wishes to perform. This should be contrasted with system software which is involved in integrating a computer's various capabilities, but typically does not directly apply them in the performance of tasks that benefit the user. In this context the term application refers to both the application software and its implementation.

Mode of operation

2008-03-08T21:57:00.001+08:00

example & function of each of the Mode of Operation

1) Single program operation

The Operating System supervises the loading and running of one program at a time and the input and output of data from and to peripheral devices.

2) Multiprocessing

Multiprocessing is the use of two or more central processing units (CPUs) within a single computer system. The term also refers to the ability of a system to support more than one processor and/or the ability to allocate tasks between them. There are many variations on this basic theme, and the definition of multiprocessing can vary with context, mostly as a function of how CPUs are defined (multiple cores on one die, multiple chips in one package, multiple packages in one system unit, etc.).

Multiprocessing sometimes refers to the execution of multiple concurrent software processes in a system as opposed to a single process at any one instant. However, the term multiprogramming is more appropriate to describe this concept, which is implemented mostly in software, whereas multiprocessing is more appropriate to describe the use of multiple hardware CPUs. A system can be both multiprocessing and multiprogramming, only one of the two, or neither of the two.

3)Multiprogramming

the execution of two or more computer programs by a single computer.

Several different programs in batch were loaded in the computer memory, and the first one began to run. When the first program reached an instruction waiting for a peripheral, the context of this program was stored away, and the second program in memory was given a chance to run. The process continued until all programs finished running.

4) Batch Processing

A popular computerized batch processing procedure is printing. This normally involves the operator selecting the documents they need printed and indicating to the batch printing software when and where they should be output. Batch processing is also used for efficient bulk database updates and automated transaction processing, as contrasted to interactive online transaction processing (OLTP) applications.
It allows sharing of computer resources among many users.

There is no interaction between the user and the computer during batch processing.
One or more programs are submitted to the computer as a job and put in a batch queue until it is their turn to be run.

5) Real - time processing

data processing fast enough to keep up with an outside process.

Real-time systems can be be of different types; process control, information storage and retrieval and transaction processing.
In any of these systems, the data input to the computer must be processed immediately. A fast response is required but whereas a few seconds delay may be acceptable in an information retrieval system, response must be instantaneous in a process control system which might for example be monitoring a chemical reaction and so on.

3 purposes of O.S. video

2008-03-08T02:27:00.003+08:00

Three Purposes of an Operating System

State the purpose of each of the following pieces of utility software.

2008-03-06T13:09:00.003+08:00

Utility software

1) Disk formatting

To divide up the surface of a disk into more easily manageable sectors.

Disk formatting is the process of preparing a hard disk or other storage medium for use, including setting up an empty file system. A variety of utilities and programs exist for this task; pictured to the right is the iconic FORMAT.COM of MS-DOS and PC-DOS.

2) File handling

To manage the files that are stored on a computer system.

temporary reference (typically a number) assigned by the operating system to a file that an application has asked the OS to open. The handle is used throughout the session to access the file.

3) Hardware drivers

Used to control communication between computer and peripherals.

A device driver simplifies programming by acting as a translator between a device and the applications or operating systems that use it. The higher-level code can be written independently of whatever specific hardware device it may control. Every version of a device, such as a printer, requires its own specialized commands. In contrast, most applications access devices (such as sending a file to a printer) by using high-level, generic commands, such as PRINTLN. The driver accepts these generic statements and converts them into the low-level commands required by the device.

4) File compression

Reduces size of files without the loss of any detail.

data compression or source coding is the process of encoding information using fewer bits (or other information-bearing units) than an un-encoded representation would use through use of specific encoding schemes. For example, this article could be encoded with fewer bits if one were to accept the convention that the word "compression" be encoded as "comp." One popular instance of compression with which many computer users are familiar is the ZIP file format, which, as well as providing compression, acts as an archiver, storing many files in a single output file.
Compression is useful because it helps reduce the consumption of expensive resources, such as hard disk space or transmission bandwidth

5) Virus checker

Used to check any files on or entering the system for viruses.

Examining (scanning) files to look for known viruses matching definitions in a virus dictionary Identifying suspicious behavior from any computer program which might indicate infection. Such analysis may include data captures, port monitoring and other methods.

The Components of a computer system and modes of use

2008-03-05T09:22:00.003+08:00

Two examples with its purposes of the following types of the following categories of software.

1) General purpose application software

Accounting software is application software that records and processes accounting transactions within functional modules such as accounts payable, accounts receivable, payroll, and trial balance. It functions as an accounting information system. It may be developed in-house by the company or organization using it, may be purchased from a third party, or may be a combination of a third-party application software package with local modifications.

computer algebra system (CAS) is a software program that facilitates symbolic mathematics. The core functionality of a CAS is manipulation of mathematical expressions in symbolic form.

2) Special purpose application software

User-written software tailors systems to meet the user's specific needs. User-written software include spreadsheet templates, word processor macros, scientific simulations, graphics and animation scripts. Even email filters are a kind of user software. Users create this software themselves and often overlook how important it is.

3) Programming languages, compilers and interpreters

An artificial language used to write instructions that can be translated into machine language and then executed by a computer.

A prominent purpose of programming languages is to provide instructions to a computer. As such, programming languages differ from most other forms of human expression in that they require a greater degree of precision and completeness. When using a natural language to communicate with other people, human authors and speakers can be ambiguous and make small errors, and still expect their intent to be understood. However, computers do exactly what they are told to do, and cannot understand the code the programmer "intended" to write. The combination of the language definition, the program, and the program's inputs must fully specify the external behavior that occurs when the program is executed.

example; assembly language, C++

Compiled languages

BASIC (Beginner's All-purpose Symbolic Instruction Code) was designed to provide access for non-science students to computers.

Java (programming language) The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities. Java applications are typically compiled to bytecode which can run on any Java virtual machine (JVM) regardless of computer architecture.

Interpreted languages

Pascal, as a small and efficient language intended to encourage good programming practices using so called structured programming and data structuring. A derivative known as Object Pascal was designed for object oriented programming.

(GML) Game Maker Language, as a small and efficient language intended to encourage good programming practices using so called structured programming and data structuring. A derivative known as Object Pascal was designed for object oriented programming.

4) Operating systems

Common contemporary desktop Operating Systems are Linux, Mac OS X, Microsoft Windows and Solaris. Windows is most popular on desktops while Linux is most popular in server environments.

• performs basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating computer networking and managing files.

5) Utility programs

Disk defragmenters.

Examples include a disk defragmenter which can detect computer files whose contents have been stored on the hard disk in disjointed fragments, and move the fragments together to increase efficiency; a disk checker can scan the contents of a hard disk to find files or areas that are corrupted in some way, or were not correctly saved, and eliminate them for a more efficiently operating hard drive; a disk cleaner can find files that unnecessary to computer operation, or take up considerable amounts of space. Disk cleaner helps the user to decide what to delete when their hard disk is full.

System Profilers.

A system profiler can provide detailed information about the software installed and hardware attached to the computer. Backup software can make a copy of all information stored on a computer, and restore either the entire system (e.g. in an event of disk failure) or selected files (e.g. in an event of accidental deletion). Disk compression software can transparently compress the contents of the hard disk, in order to fit more information to the drive.

3 types of hardware and their uses

2008-03-04T10:49:00.001+08:00

THREE types of hardware and their uses

1) Sound card

Enables the computer to output sound to audio devices, as well as accept input from a microphone. Most modern computers have sound cards built-in to the motherboard, though it is common for a user to install a separate sound card as an upgrade.

2) Keyboard

a device, to input text and characters by depressing buttons (referred to as keys), similar to a typewriter. The most common English-language key layout is the QWERTY layout. A majority of all keyboard keys produce letters, numbers or signs (characters) that are appropriate for the operator's language. Other keys can produce actions when pressed, and other actions are available by the simultaneous pressing of more than one action key.

3) Speakers

a device that converts analog audio signals into the equivalent air vibrations in order to make audible sound.

Cmparison of various email accounts & Operating System

2008-03-03T21:02:00.004+08:00

Comparison of various email accounts and Operating Systems

Email accounts;

Hotmail

Familiar, fast, powerful

5 GB of inbox storage
New design: choose your own colours and layout
Get started in the familiar-looking classic version—switch to the full view anytime for advanced features

Security by Microsoft

See at a glance if an e-mail seems to be suspicious
Destroy junk e-mail with a single click
Powerful virus scanning and cleaning

Looks and feels more like Outlook—on the Web

Preview your messages in the reading pane
Works more like Microsoft Office Outlook: customizable reading pane,
Drag-and-drop powers of organization

Gmail

6 GB+/20 MB of inbox storage.

~1500 bytes added every second.

Free IMAP
Sync your inbox across devices instantly and automatically. Whether you read or write your email on your phone or on your desktop, changes you make to Gmail will be seen from anywhere you access your inbox.

Virus scanning
For your protection, Gmail now automatically scans for viruses every time you open or send a message with an attachment.

Yahoo!

Unlimited mail storage.
10 MB attachments (20 MB for long-time users)
Protection against spam and viruses.
Some users get features added if they are long time users.

The Classic version of Yahoo! mail

Operating Systems;

Microsoft Windows

Creator - Microsoft.
Faster start-up and hibernation sequences.
The ability to discard a newer device driver in favour of the previous one (known as driver rollback), should a driver upgrade not produce desirable results.
A new, arguably more user-friendly interface, including the framework for developing themes for the desktop environment.
Fast user switching, which allows a user to save the current state and open appli cations of their desktop and allow another user to log on without losing that information.
The ClearType font rendering mechanism, which is designed to improve text readability on Liquid Crystal Display (LCD) and similar monitors.
Remote Desktop functionality, which allows users to connect to a computer running Windows XP from across a network or the Internet and access their applications, files, printers, and devices.
Support for most DSL modems and wireless network connections, as well as networking over FireWire, and Bluetooth.

Mac OS X

Creator - Apple Inc.
Aqua GUI – A fluid graphical user interface with glass-like elements.
Automator – an application designed to create an automatic workflow for different tasks.
Dashboard – A full-screen group of small applications called desktop widgets that can be called up and dismissed in one keystroke.
Expose' – A feature which includes three functions to help accessibility between windows and desktop. Its functions are to instantly display all open windows as thumbnails for easy navigation to different tasks, display all open windows as thumbnails from the current application, and hide all windows to access the desktop.
Finder – A file browser allowing quick access to all areas of the computer ( modified throughout subsequent releases). (The Finder found in Mac OS X Jaguar had been criticized by John Siracusa for violating the concept of spatial inference.)
- Quick look allows dynamic previews of files (including videos and multi-page documents) without opening their parent applications.
- Spotlight search technology allows rapid real-time searches of data files, mail messages, photos, and other information, based on item properties (meta data) and/or content.
FileVault – Optional encryption of the user's files with Advanced encryption Standard (AES).
Front Row – A media viewer interface accessed by the Apple Remote.
Global application services – spell checker, special characters palette, color picker, font chooser and dictionary.
Integrated Sync Services – A system which allows applications to access a centralized extensible database for various elements of user data, including calendar and contact items. The operating system manages conflicting edits and data consistency.
Spaces – Desktop organization tool which can create and manage multiple virtual desktops and display them in an Exposé-like interface.
Cover Flow – is a three-dimensional graphical user interface included with iTunes, the Finder, and other Apple Inc. products for visually skimming through files and digital media libraries via cover artwork.
Time Machine – Automatic backup technology that allows users to view and restore previous versions of files and application data