Learnings of the Week :)

LEARNINGS OF THE WEEK

(2nd grading)

by: Mary Trishia V. Tabigue IV-RIZAL

OVERVIEW OF C LANGUAGE

History of C Language

.B was developed in the year 1970 by Ken Thompson. The said language is a successor of Basic Command Programming Language (BCPL), which was developed by Martin Richards.

.To augment B’s power, Dennis Ritchie invented and first implemented the C Programming Language in Bell Laboratory.

.C was originally developed under UNIX environment running in DEC PDP-11.

.C stands for Combined Programming Language and sometimes called System Programming Language (SPL).

.It did not become immediately popular after its creation. It took almost six years when many people read and learned the usefulness of the language after Brian Kernighan and Dennis Ritchie created a famous book called “THE C PROGRAMMING LANGUAGE”.

.X3J11 committee was created in the year 1983 under the American National Standard Institute (ANSI) to provide machine definition of the language and was than approved in 1989.

.ANSI cooperated with the International Standard Organization (ISO) to refer to as ANSI/ISO 9899:1990”.

.C is often called a middle-level language. C as a middle-level language means that it combines elements of high-level language with the functionalism of assembly language. It allows manipulation of bits, bytes, and addresses the basic elements with which the computer functions.

.Input commands, output commands, and special words often referred to as reserved words allow the use of lower case only.

.They should be written in lower case since C is sensitive to those words. They have only 32 keywords (27 from Kernighan and Ritchie standard and 5 added by the ANSI Standardization Committee.

.C was initially used for system development work, in particular the programs that make up the operating system.

.C is used mainly because it produces codes that run as fast as codes written in assembly language.

Some Examples Uses of C

.Operating system
.Language compilers
.Assemblers
.Text editors
.Print spoolers
.Network devices
.Modern programs
.Databases
.Language Interpreters
.Utilities

Features of C Languages

-A simple core language, such as math functions or file handling provided by a standard set of library routines.

-Focus on procedural programming paradigm which facilitates for programming in a structured style.

-Parameters are always passed by value, never by reference.

-C encourages the creation of libraries user-defined functions.

-C is flexible when it allows unrestricted conversion of data from one type to another, such as conversion of a character to its numeric equivalent.

FLOWCHARTING AND ALGORITHMS

Flowcharting Defined

-Use of symbols and phrases to designate the logic of how a problem is solved.
-A common method for defining the logical steps of flow within a program by using a series of symbols to identify the basic input, process and output function within a program.

-A two-dimensional representation of an algorithm; the predefined graphic symbols of a flowchart are used to indicates the various operations and the flow of control .

-A diagram representing the logical sequence in which a combination of steps is to be performed. It is a blueprint of the program.

Algorithm Defined

-Algorithm is a finite set of instructions that specify a sequence of operations to be carried out in order to solve a specific problem or class of problems.

Basic Symbols Used in Flowcharting

Terminal (shape: rectangle with soft curves)
-Used to signify the beginning and end of flowchart.

Preparation/Initialization (shape: hexagon)

-Signifies the preparation of data.
-Used to select initial conditions.

-Used to represent instructions or groups of instructions that will alter or modify a program’s course of execution.

Input/ Output (shape: parallelogram)

-Shows input and output. Data are to be read into the computer memory from an input device or data are to be passed from the memory to an output device.

Processing (shape: rectangle)

-Performs any calculations that are to be done.

Decision (shape: diamond)

-Signifies any decisions that are to be done.

On-page Connector (shape: circle)

-Shows the entry or exit point of the flowchart.
-A non-processing symbol used to connect one part of a flowchart to another without drawing flow lines.
-Conserves space by keeping related blocks near one another, reduces the number of flow lines in complex programs, and eliminates cross lines from taking place.

Off-page Connector (shape: inverted pentagon)

-Designates entry to or exit from one page when a flowchart requires more than one page.

Flowlines (arrows)
-Signifies the process that is to be executed next.

Basic Control Structures
-Sequence
-Selection (if-then-else)
-Repetition (Looping)

Sequence
A process executed from one to another in a straightforward manner.

Selection (if – then – else)
A choice is provided between alternatives.

Repetition (Looping)
This structure provides for the repetitive execution of an operation or routine while the condition is true. The condition is evaluated before executing any process statement. As long as the condition is true, the process is executed, otherwise, control flows out of the structure.

Commonly Used Operators in Flowcharting

Arithmetic Operators

+ Addition
- Subtraction
* Multiplication
/ Division

Relational Operators

= equal
> Greater than
< less than
<> Not equal
> Greater than or equal to
< less than or equal to

Logical operators

&& AND
ll OR
! NOT

- - - - - - - - - - - - E N D - - - - - - - - - - - -

Learnings of the Week (ROLLORATA)

Our second topic was all about FLOWCHARTING. I thought this topic will be a lot simpler than our lessons before. Yet, this is really a tough one. It needed analysis and good decision-making. We first defined flowcharting as the use of symbols and phrases to designate the logic of how a problem is solved and a common method for defining the logical steps of flow within a program by using a series of symbols to identify the basic input, process and output function within a program. We then tackled about the contents of the flowchart. One of which is the algorithm. Algorithm is a finite set of instructions that specify a sequence of operations to be carried out in order to solve a specific problem or class of problems. Symbols are used to represent the beginning, preparation, input and output, processing, decision-making, off-page and on-page connectors, flow lines and the symbol for the end. The basic control structures are the sequence, selection and repetition or looping.

Our teacher then elaborated the basic control structures. The simplest of the three is the sequence. It is the process executed from one to another in a straightforward manner. So the sequence is continuous and you will not anymore undergo decision-making. Secondly, the selection, a choice is provided between alternatives. This involves the symbol for decision which is diamond and branches two flow lines, for true and false. The toughest one is the repetition. This structure provides for the repetitive execution of an operation or routine while the condition is true. The condition is evaluated before executing any process statement. As long as the condition is true, the process is executed, otherwise, control flows out of the structure. The commonly used operators for the flowchart are the ARITHMETIC, RELATIONAL and LOGICAL operators.

LEARNINGS OF THE WEEK (TAGARO)

LEARNINGS OF THE WEEK

By: Sharra Mae S. Tagaro IV- Rizal

This week, I learned about the facts about C language.

• B was developed in the year 1970 by Ken Thompson. The said language is a successor of Basic Command Programming Language (BCPL), which was developed by Martin Richards.

• C was originally developed under UNIX environment running in DEC PDP-11.

• C stands for Combined Programming Language and sometimes called System Programming Language (SPL).

• It did not become immediately popular after its creation. It took almost six years when many people read and learned the usefulness of the language after Brian Kernighan and Dennis Ritchie created a famous book called “THE C PROGRAMMING LANGUAGE”.

• X3J11 committee was created in the year 1983 under the American National Standard Institute (ANSI) to provide machine definition of the language and was than approved in 1989.

• Input commands, output commands, and special words often referred to as reserved words allow the use of lower case only.

• They should be written in lower case since C is sensitive to those words. They have only 32 keywords (27 from Kernighan and Ritchie standard and 5 added by the ANSI Standardization Committee.

• C was initially used for system development work, in particular the programs that make up the operating system.

• C is used mainly because it produces codes that run as fast as codes written in assembly language.

• These are some of the uses of C:C is used as an Operating system;Language compilers;Assemblers;Text editors;Print spoolers;Network devices;Modern programs;Databases;Language Interpreters; and Utilities.

• A simple core language, such as math functions or file handling provided by a standard set of library routines.

• Focus on procedural programming paradigm which facilitates for programming in a structured style.

• Parameters are always passed by value, never by reference.

• C encourages the creation of libraries user-defined functions.

• C is flexible when it allows unrestricted conversion of data from one type to another, such as conversion of a character to its numeric equivalent.

Well I guess that is all i have learned about C. But don't you worry there are many more facts about C that our teacher will teach us.

I also learned about flowcharting and its basic control structures.

• Flowcharting- A common method for defining the logical steps of flow within a program by using a series of symbols to identify the basic input, process and output function within a program.

• A two-dimensional representation of an algorithm; the predefined graphic symbols of a flowchart are used to indicates the various operations and the flow of control .

• Algorithm- a finite set of instructions that specify a sequence of operations to be carried out in order to solve a specific problem or class of problems.

• There are many basic symbols used in flowcharting.

• Basic control structures: Sequence- A process executed from one to another in a straightforward manner. Selection- A choice is provided between alternatives. Repetition- This structure provides for the repetitive execution of an operation or routine while the condition is true. The condition is evaluated before executing any process statement. As long as the condition is true, the process is executed, otherwise, control flows out of the structure.

LEARNINGS OF THE WEEK (TAGARO)

LEARNINGS OF THE WEEK
By: Sharra Mae S. Tagaro IV- Rizal

This week, I learned how to convert characters into binary digits, hexadecimal and decimal. FOR EXAMPLE:

CHARACTERS	BINARY DIGITS	DECIMAL	HEXADECIMAL
S	1010011	83	53
h	1101000	104	68
a	1100001	97	61
r	1110010	114	72
r	1110010	114	72
a	1100001	97	61
	00100000	32	20
M	1001101	77	4D
a	1100001	97	61
e	1100101	101	65
	00100000	32	20
S	1010011	83	53
.	101110	46	2E
	00100000	32	20
T	1010100	84	54
a	1100001	97	61
g	1100111	103	67
a	1100001	97	61
r	1110010	114	72
o	1101111	111	6F

Learnings of the Week (ROLLORATA)

Our very first topic for the second quarter is all about the C LANGUAGE. Let’s us now begin from the history of the C Language. B was developed in the year 1970 by Ken Thompson. The said language is a successor of Basic Command Programming Language (BCPL), which was developed by Martin Richards. To augment B’s power, Dennis Ritchie invented and first implemented the C Programming Language in Bell Laboratory. C was originally developed under UNIX environment running in DEC PDP-11. C stands for Combined Programming Language and sometimes called System Programming Language (SPL). It did not become immediately popular after its creation. It took almost six years when many people read and learned the usefulness of the language after Brian Kernighan and Dennis Ritchie created a famous book called “THE C PROGRAMMING LANGUAGE”. X3J11 committee was created in the year 1983 under the American National Standard Institute (ANSI) to provide machine definition of the language and was than approved in 1989. ANSI cooperated with the International Standard Organization (ISO) to refer to as ANSI/ISO 9899:1990”. C is often called a middle-level language. C as a middle-level language means that it combines elements of high-level language with the functionalism of assembly language. It allows manipulation of bits, bytes, and addresses the basic elements with which the computer functions. Input commands, output commands, and special words often referred to as reserved words allow the use of lower case only. They should be written in lower case since C is sensitive to those words. They have only 32 keywords (27 from Kernighan and Ritchie standard and 5 added by the ANSI Standardization Committee. C was initially used for system development work, in particular the programs that make up the operating system. C is used mainly because it produces codes that run as fast as codes written in assembly language. C has many uses such as Operating system, Language compilers, Assemblers, Text editors, Print spoolers, Network devices, Modern programs, Databases, Language Interpreters and Utilities. It also has its features like it has a simple core language, such as math functions or file handling provided by a standard set of library routines. It focuses on procedural programming paradigm which facilitates for programming in a structured style. Parameters are always passed by value, never by reference. C encourages the creation of libraries user-defined functions. C is flexible when it allows unrestricted conversion of data from one type to another, such as conversion of a character to its numeric equivalent. And that was our first topic for the second quarter.

LEARNINGS OF THE WEEK (TAGARO)

LEARNINGS OF THE WEEK

By: Sharra Mae S. Tagaro IV- Rizal

SOFTWARE

- is a general term used to describe a collection of computer programs, procedures and documentation that perform some tasks on a computer system.

Kinds of system software

1. Application software- allows end users to accomplish one or more specific (non-computer related) tasks. Typical applications include industrial automation, business software, educational software, medical software, databases, and computer games. Businesses are probably the biggest users of application software, but almost every field of human activity now uses some form of application software.

2. Operating system- is the software component of a computer system that is responsible for the management and coordination of activities and the sharing of the resources of the computer. The operating system acts as a host for application programs that are run on the machine. As a host, one of the purposes of an operating system is to handle the details of the operation of the hardware. This relieves application programs from having to manage these details and makes it easier to write applications. Almost all computers, including hand-held computers, desktop computers, supercomputers, and even modern video game consoles, use an operating system of some type. Some of the oldest models may however use an embedded OS, that may be contained on a compact disk or other storage device.

3. Programming languages- A language used to write instructions for the computer. It lets the programmer express data processing in a symbolic manner without regard to machine-specific details.

A.Machine language- For the first machines in the 1940s, programmers had no choice but to write in the sequences of digits that the computer executed. For example, assume we want to compute the absolute value of A + B − C, where A is the value at machine address 3012, B is the value at address 3013, and C is the value at address 3014, and then store this value at address 3015.

B.Assembly languages- Since each component of a program stands for an object that the programmer understands, using its name rather than numbers should make it easier to program. By naming all locations with easy-to-remember names, and by using symbolic names for machine instructions, some of the difficulties of machine programming can be eliminated. A relatively simple program called an assembler converts this symbolic notation into an equivalent machine language program.

C.High- level languages- The first programming languages were developed in the late 1950s. The concept was that if we want to compute A + B − C, and store the result in a memory location called D, all we had to do was write D = A + B − C and let a computer program, the compiler, convert that into the sequences of numbers that the computer could execute. FORTRAN (an acronym for Formula Translation) was the first major language in this period.

FORTRAN statements were patterned after mathematical notation. In mathematics the = symbol implies that both sides of the equation have the same value. However, in FORTRAN and some other languages, the equal sign is known as the assignment operator. The action carried out by the computer when it encounters this operator is, “Make the variable named on the left of the equal sign have the same value as the expression on the right.” Because of this, in some early languages the statement would have been written as −D → D to imply movement or change, but the use of → as an assignment operator has all but disappeared.

LEARNINGS OF THE WEEK

By: Sharra Mae S. Tagaro IV- Rizal

Fundamental elements of a computer

2.Output Devices- An output device is any peripheral device that presents, displays, alters or records output after it has left a computer’s system unit. Output device data can appear in various forms such as graphics, laser light, sound, or text. Examples of output devices are computer speaker, monitor, Printer.

A.computer speaker- converts output data into sound.

B.monitor- give users visual presentation of keyboard commands and mouse movements.

C.printer- creates images on paper, plastic, and other print media.

a.laser printers- uses toner and an internal laser to print.

b.inkjet printers- uses ink to print.

c.dot- matrix printer- creates characters by sriking pins against an ink ribbon.

characteristics of printers

*quality of type

*speed

*impact or non- impact

*graphics

3.Input devices- An input device is any peripheral appliance that generates input for the computer and allows user to enter information into the computer to be processed. Input devices allow users to provide a computer with commands, software, instructions, and information. Examples of input devices are keyboard, Microphone, scanner, Digital Camera, Graphic Tablet, Joy stick.

A.Keyboard- set of typewriter like keys that enables you to enter data into a computer.

a.alphanumeric keys

b.punctuation keys

c.special keys

B.Mouse- a device that controls the movements of the cursor on the screen.

C.Microphone- allows the computer to recieve and record sound.

D.Scanner- used to create a computerized version of a photo.

E.Digital camera- takes picture without a film.

F.Graphic tablet- objects are drawn using a pen or a puck.

G.Joystick- a handheld stick; used to control computer games.

Five Elements of Computing Process

1.Hardware- components that can be physically handled.

2.Software- instruction that tell the hardware what to do.

3.Data- the raw facts that the computer can change into useful information.

4.People- the "end users".

5.Procedure- steps that the end user must follow.

LEARNINGS OF THE WEEK

By: Sharra Mae S. Tagaro IV- Rizal

Computer-A computer is an electronic device that helps people perform different task.
-An electronic device that stores, retrieves, and processes data, and can be programmed with instructions.
Types of computers:
1.Microcomputers
The term microcomputer is generally synonymous with personal computer (PC), or a computer that depends on a microprocessor.
a.Personal computer or PC-A small, relatively inexpensive computer designed for an individual user. In price, personal computers range anywhere from a few hundred dollars to thousands of dollars. All are based on the microprocessor technology that enables manufacturers to put an entire CPU on one chip.
b.Portable computer- A portable computer is a computer that is designed to be moved from one place to another (in other words, it is a computer that is portable). Portable computers, by their nature, are microcomputers. These includes laptops or notebook, sub-notebooks, tablet computer and personal digital assistant.
2.Minicomputers
Midsized computer. In size and power, minicomputers lie between workstations and mainframes. In the past decade, the distinction between large minicomputers and small mainframes has blurred, however, as has the distinction between small minicomputers and workstations. But in general, a minicomputer is a multiprocessing system capable of supporting from 4 to about 200 users simultaneously.
3.Mainframe computers
A very large and expensive computer capable of supporting hundreds, or even thousands, of users simultaneously. In the hierarchy that starts with a simple microprocessor (in watches, for example) at the bottom and moves to supercomputers at the top, mainframes are just below supercomputers. In some ways, mainframes are more powerful than supercomputers because they support more simultaneous programs. But supercomputers can execute a single program faster than a mainframe. The distinction between small mainframes and minicomputers is vague, depending really on how the manufacturer wants to market its machines.
4.Supercomputers
The fastest type of computer. Supercomputers are very expensive and are employed for specialized applications that require immense amounts of mathematical calculations. For example, weather forecasting requires a supercomputer.
The chief difference between a supercomputer and a mainframe is that a supercomputer channels all its power into executing a few programs as fast as possible, whereas a mainframe uses its power to execute many programs concurrently.

Learnings of the week.

Learnings of the Week

by: Mary Trishia V. Tabigue

3 FUNDAMENTAL ELEMENTS OF A COMPUTER

•System Unit
•Output Devices
•Input Devices

•The system unit acts like the center or core, processing the data and information it receives from input devices.
•Output devices like printers receive the system unit’s processed information

The System case

•The system case is a plastic and metal box that houses components such as the motherboard, disk drives and power supply unit.

System Case Types

•There are two basic types of system case: desktop and tower.
•Desktop case: is designed to sit horizontally on a surface, so that it is wider than it is long. These are usually used for office or home PCs. 2 basic sizes: standard and slimline.

•Tower case: is designed to sit vertically on a surface, so that it is higher than it is wide. 3 basic sizes: full, midi and mini.

•Full-tower cases: are usually used for PC servers.
•Midi-tower cases: are used for higher-end user PCs.
•Mini-tower cases: are usually for office or home PCs.

Parts of the Case

•Cover: the case has a cover which is removed by either undoing the screws at the back, or pressing together clips that release it.
•Front Panel: provides access to the floppy and CD, a power on/off switch, a reset switch, and LEDs (light Emitting Diodes) to indicate drive operation.
Parts of front panel cover: CD-R and CD-RW drives, removable hard disk, 3.5 floppy disk,3.5 drive bays, LEDs, Reset switch, Power on/off switch.

THE MOTHERBOARD

•The motherboard is the largest board of the computer system.
•The motherboard contains the CPU, BIOS, memory, mass storage interfaces, serial and all the controllers required to control standard peripheral devices, such as the display screen, keyboard, and disk drive.
•Chipset: chips that reside on the motherboard.

•The mother board battery: is used to preserve the computer’s clock’s time and your BIOS settings while the computer is turned off.

THE CENTRAL PROCESSING UNIT-CPU

•Is the device that interprets and executes instructions.
•Today’s single-chip central processing units, called microprocessors, make personal computers and workstations possible.
•It has the ability to fetch, decode, and execute instructions and transfer information to and from other resources over the computer’s main data-transfer path, the bus.
•It functions as the brain of a computer

CLOCK

•The system clock synchronizes the operation of all parts of the PC.
•It consists of a clock generator that sets up a timing signal, and clock multipliers.

MEMORY

•2 fundamental types:
–main memory and
–secondary memory

MAIN MEMORY

•Very closely connected to the processor.
•The contents are quickly and easily changed.
•Holds the programs and data that the processor is actively working with.
•Interacts with the processor millions of times per second.

•Most computers available today have memory capacities of 64Mb to 256Mb.
•When programs and data become active, they are copied from secondary memory into main memory where the processor can interact with them.
•Main memory sometimes called: RAM
•RAM (Random Access Memory), radom means that the memory cells can be accessed in any order.

RANDOM ACCESS MEMORY (RAM)

•It means the computer can store, retrieve, alter or delete any items held in the RAM’s at random.
•It is a semiconductor-based memory that can read and written.
•Main memory is build from small circuit boards called MEMORY MODULES.

•Still the current standard in system memory, usually of SDRAM (synchronous RAM) type.
•DIMM chips are usually distributed in 64MB, 128MB or 256 MB on a single chip.
•DIMMs (dual inline memory module) have two access pathways, they do not need to be fitted in pairs as they can be written to and read at the same time

ROM BIOS

•The BIOS (basic input output system) is a ROM (read only memory) chips that provides:
–The industry standard program code that operates the fundamental components of the PC (for example, VDU, keyboard, printer port) and ensures that the design of each manufacturer’s motherboard is PC-compatible.
–The routines that allow the setup configuration of a PC (stored in the CMOS RAM) to be viewed and edited.
–The power-on self-test (POST) diagnostic tests for the PC

•BIOS chip cannot be swapped between different motherboards.
•The BIOS is often known as firmware as it consists of both the physical chip (hardware) and the programs coded into it (software).
•The ROM BIOS is normally a DIP chip that can be identified by a label on the chip.

CMOS RAM

•CMOS RAM stores the configuration of the PC.
•CMOS stands for Complimentary Metal-Oxide Semiconductors, which describes the manufacturing process used to make RAM chip.
•The CMOS battery is either a NICard, lithium or alkaline cell

SECONDARY MEMORY

•Connected to main memory through the bus and a controller
•The contents are easily changed, but this is very slow compared to main memory
•Used for long-term storage of programs and data
•The processor only occasionally interacts with secondary memory

•Common secondary storage devices are the floppy disk and hard disks and compact disks or CD
•It is a thin and flimsy as a sheet of paper but is protected by the sturdy, square jacket that encases it.
•Since the rust is made of iron, which can be magnetized, the disks stores magnetic signals.
•The pattern of magnetic signals is a code representing your data

•3 Standard sizes:
–8-inch is called a largefloppy
–5.25-inch is called a minifloppy
–3.5-inch is called a microfloppy

•5.25-inch floppies were invented by Shugart Associates
•3.35-inch floppies were invented by Sony.
•The typical 3.5 floppy drive holds 1.44 MB.

Drive

•Zip, the most popular super-capacity floppy disks is the Zip disk.
•It holds 100M, which is 70 times as much as 1.44M floppy

HARD DISK

•Might have a storage capacity of 40 gigabytes. This is about 300 times the amount of storage in main memory (assuming 128 megabytes of main memory)
•Hard Drives are usually designated as Drive C

•Hard disks are better than floppy disks in three ways:
–Hard disks are sturdier than floppies
–Hard disks are hard and firm; they don’t flop or jiggle. They’re more reliable than floppies
–Hard drives hold more info. Than floppy drives.

•The typical hard drive holds 40 gigabytes.
•The typical floppy disk rotates between 5 and 10 times per second.
•The typical floppy disk rotates between 5-10 times/second. The typical hard disk rotates between 90-167 times/second.
•The hard disk is non-removable

CD-ROMs

•CD that holds music is called a music CD
•A CD that holds computer data instead is called a computer CD
•The standard CD-ROM disks has a diameter of 12 centimeters and holds 650 megabytes.
•The CD can hold 99 tracks, totaling an hour of music or 650 Mb.

CD-RW

•CD-rewritable drive, which can write onto a blank CD-RW disk and then edit what you wrote.

DVD

•1997, the electronic industry selling an improved kind of CD, called a Digital Versatile Disk (DVD)
•Holds 2-hour movie (including the video and sound)
•Movie Lovers call it a Digital Video Disk

VIDEO CARD

•A board that pugs into a personal computer to give it display capabilities
•Graphics Accelerator: adapters graphics coprocessor for performing graphics calculations
•Video Card are also called video adapter, video board , video display board, graphics card and graphics

UNDERSTANDING VIDEO GRAPHICS

•The video/graphics card converts digital data into signals that can be sent across a connector to you monitor, which interprets the signal into an image on screen.

Learnings of the Week (ROLLORATA)

JULY 28 - AUGUST 1, 2008

In this week, we went back to class discussion because last week we had our cooking and movie viewing. Our topic was all about the types of computers. We then defined computer as a device that uses digital technology to process and manipulate information. The types of computers are Microcomputers, Workstation, Minicomputers, Mainframe Computers, Supercomputers and Wearable Computers. The term microcomputer is generally synonymous with personal computer (PC), or a computer that depends on a microprocessor. A personal computer is a small, relatively inexpensive computer designed for an individual user. A portable computer is a computer that is designed to be moved from one place to another (in other words, it is a computer that is portable). A workstation is a desktop computer that has a more powerful processor, additional memory and enhanced capabilities for performing a special group of task, such as 3D Graphics or game development. Midsized computer. In size and power, minicomputers lie between workstations and mainframes. In the past decade, the distinction between large minicomputers and small mainframes has blurred, however, as has the distinction between small minicomputers and workstations. But in general, a minicomputer is a multiprocessing system capable of supporting from 4 to about 200 users simultaneously. Mainframe computers is a very large and expensive computer capable of supporting hundreds, or even thousands, of users simultaneously. In the hierarchy that starts with a simple microprocessor (in watches, for example) at the bottom and moves to supercomputers at the top, mainframes are just below supercomputers. The fastest type of computer. Supercomputers are very expensive and are employed for specialized applications that require immense amounts of mathematical calculations. The latest trend in computing is wearable computers. Essentially, common computer applications (e-mail, database, multimedia, calendar/scheduler) are integrated into watches, cell phones, visors and even clothing!

3 FUNDAMENTAL ELEMENTS OF A COMPUTER

• System Unit

• Output Devices

• Input Devices

The system unit acts like the center or core, processing the data and information it receives from input devices. Output devices like printers receive the system unit’s processed information

The System case

The system case is a plastic and metal box that houses components such as the motherboard, disk drives and power supply unit.

System Case Types

There are two basic types of system case: desktop and tower.

Desktop case: is designed to sit horizontally on a surface, so that it is wider than it is long. These are usually used for office or home PCs. 2 basic sizes: standard and slimline.

Tower case: is designed to sit vertically on a surface, so that it is higher than it is wide. 3 basic sizes: full, midi and mini.

• Full-tower cases: are usually used for PC servers.

• Midi-tower cases: are used for higher-end user PCs.

• Mini-tower cases: are usually for office or home PCs.

Parts of the Case

Cover: the case has a cover which is removed by either undoing the screws at the back, or pressing together clips that release it.

Front Panel: provides access to the floppy and CD, a power on/off switch, a reset switch, and LEDs (light Emitting Diodes) to indicate drive operation.

Parts of front panel cover: CD-R and CD-RW drives, removable hard disk, 3.5 floppy disk,3.5 drive bays, LEDs, Reset switch, Power on/off switch.

THE MOTHERBOARD

The motherboard is the largest board of the computer system. The motherboard contains the CPU, BIOS, memory, mass storage interfaces, serial and all the controllers required to control standard peripheral devices, such as the display screen, keyboard, and disk drive.

Chipset: chips that reside on the motherboard.

The mother board battery: is used to preserve the computer’s clock’s time and your BIOS settings while the computer is turned off.

THE CENTRAL PROCESSING UNIT-CPU

• Is the device that interprets and executes instructions.

• Today’s single-chip central processing units, called microprocessors, make personal computers and workstations possible.

• It has the ability to fetch, decode, and execute instructions and transfer information to and from other resources over the computer’s main data-transfer path, the bus.

• It functions as the brain of a computer

CLOCK

• The system clock synchronizes the operation of all parts of the PC.

• It consists of a clock generator that sets up a timing signal, and clock multipliers.

MEMORY

• 2 fundamental types:

  • main memory (RAM)

  • secondary memory (Floppy disk, USB)

MAIN MEMORY

• Very closely connected to the processor.

• The contents are quickly and easily changed.

• Holds the programs and data that the processor is actively working with.

• Interacts with the processor millions of times per second.

• Most computers available today have memory capacities of 64Mb to 256Mb.

• When programs and data become active, they are copied from secondary memory into main memory where the processor can interact with them.

• Main memory sometimes called: RAM

• RAM (Random Access Memory), random means that the memory cells can be accessed in any order.

RANDOM ACCESS MEMORY (RAM)

• It means the computer can store, retrieve, alter or delete any items held in the RAM’s at random.

• It is a semiconductor-based memory that can read and written.

• Main memory is build from small circuit boards called MEMORY MODULES.

• Still the current standard in system memory, usually of SDRAM (synchronous RAM) type.

• DIMM chips are usually distributed in 64MB, 128MB or 256 MB on a single chip.

• DIMMs (dual inline memory module) have two access pathways, they do not need to be fitted in pairs as they can be written to and read at the same time.

ROM BIOS

• The BIOS (basic input output system) is a ROM (read only memory) chips that provides:

  • The industry standard program code that operates the fundamental components of the PC (for example, VDU, keyboard, printer port) and ensures that the design of each manufacturer’s motherboard is PC-compatible.

  • The routines that allow the setup configuration of a PC (stored in the CMOS RAM) to be viewed and edited.

  • The power-on self-test (POST) diagnostic tests for the PC

• BIOS chip cannot be swapped between different motherboards.

• The BIOS is often known as firmware as it consists of both the physical chip (hardware) and the programs coded into it (software).

• The ROM BIOS is normally a DIP chip that can be identified by a label on the chip.

CMOS RAM

• CMOS RAM stores the configuration of the PC.

• CMOS stands for Complimentary Metal-Oxide Semiconductors, which describes the manufacturing process used to make RAM chip.

• The CMOS battery is either a NICard, lithium or alkaline cell

SECONDARY MEMORY

• Connected to main memory through the bus and a controller

• The contents are easily changed, but this is very slow compared to main memory

• Used for long-term storage of programs and data

• The processor only occasionally interacts with secondary memory

• Common secondary storage devices are the floppy disk and hard disks and compact disks or CD

• It is as thin and flimsy as a sheet of paper but is protected by the sturdy, square jacket that encases it.

• Since the rust is made of iron, which can be magnetized, the disks stores magnetic signals.

• The pattern of magnetic signals is a code representing your data

3 Standard sizes:

• 8-inch is called a largefloppy

• 5.25-inch is called a minifloppy

• 3.5-inch is called a microfloppy

5.25-inch floppies were invented by Shugart Associates

3.35-inch floppies were invented by Sony.

The typical 3.5 floppy drive holds 1.44 MB.

Drive

• Zip, the most popular super-capacity floppy disks is the Zip disk.

• It holds 100M, which is 70 times as much as 1.44M floppy

HARD DISK

• Might have a storage capacity of 40 gigabytes. This is about 300 times the amount of storage in main memory (assuming 128 megabytes of main memory)

• Hard Drives are usually designated as Drive C

• Hard disks are better than floppy disks in three ways:

  • Hard disks are sturdier than floppies

  • Hard disks are hard and firm; they don’t flop or jiggle. They’re more reliable than floppies

  • Hard drives hold more info. Than floppy drives.

• The typical hard drive holds 40 gigabytes.

• The typical floppy disk rotates between 5 and 10 times per second.

• The typical floppy disk rotates between 5-10 times/second. The typical hard disk rotates between 90-167 times/second.

• The hard disk is non-removable

CD-ROMs

• CD that holds music is called a music CD

• A CD that holds computer data instead is called a computer CD

• The standard CD-ROM disks has a diameter of 12 centimeters and holds 650 megabytes.

• The CD can hold 99 tracks, totaling an hour of music or 650 Mb.

CD-RW

• CD-rewritable drive, which can write onto a blank CD-RW disk and then edit what you wrote.

DVD

• 1997, the electronic industry selling an improved kind of CD, called a Digital Versatile Disk (DVD)

• Holds 2-hour movie (including the video and sound)

• Movie Lovers call it a Digital Video Disk

VIDEO CARD

• A board that pugs into a personal computer to give it display capabilities

• Graphics Accelerator: adapters graphics coprocessor for performing graphics calculations

• Video Card are also called video adapter, video board , video display board, graphics card and graphics

UNDERSTANDING VIDEO GRAPHICS

• The video/graphics card converts digital data into signals that can be sent across a connector to you monitor, which interprets the signal into an image on screen.