Introduction To Computing Tutorial

By Jide Awe | Contributing Writer

Hardware & Software

Hardware

In simplest terms, hardware is the physical parts associated with a computer - the electronic, magnetic, and mechanical devices (monitor, keyboard, printer, micro chip boards, floppy drives, cables and physical pieces of a system. These INPUT/OUTPUT DEVICES allow the operator to interact with the computer.

Software

Sets of programs (stored sets of instructions) that govern the operation of the computer system and make the hardware perform. These programs (instructions) tell the hardware how to do a particular task such as word

processing, games, database management, etc. Although these instructions are usually stored inside a piece of hardware (e.g., software instructions stored inside a circuit chip or floppy drive) but they are nevertheless software.

In a way, Software refers to the instructions that enable an otherwise dead machine to understand your inputs and transform them into desired outputs. Computer hardware by itself lacks personality; this is determined by the software. Word processing software turns the computer into a word processor, accounting software turns the computer into an accounting tool, etc.

Lets discuss a bit about Software before we go back to Hardware. There are two major types of software: Operating system software and Applications software.

Operating system software (like DOS, UNIX or Windows 95) performs very elemental housekeeping instructions (e.g., where is the monitor, how can I keep track of what data is on which track or sector of a floppy drive, whether more than user can work on the system at the same time e.g. UNIX.)

The operating system that all IBM and compatible PC's use is called DOS (sounds like floss). DOS is software that allows the terminal, printer, computer and mass storage systems (floppy disks) to work together as a unit, and controls the execution of programs. It also allows you to do housekeeping chores regarding managing disks and files.

Applications programs perform tasks on a higher level (e.g., word processing Spreadsheet, Games, Database Management, Accounting, Payroll programs are applications.) Generally an application software package uses the lower level operating system (DOS) to do routine tasks (e.g., your word processing application uses the lower level DOS operating system frequently to write and store data on a disk.

And what is a database?

A database is a collection of information that is organized for ease of reference. For example, your address book is a database, just as an inventory of goods, a list of all churches in your state or your staff list.

Before Electronic processing of information, databases had to be maintained on paper stored in file folders that were kept in filing cabinets. With Electronic DataBase Management Systems (DBMS), information stored electronically and be recalled instantly and accurately.

And now lets go back to Hardware:

Hardware

Central Processor Unit (CPU)

Heart of the PC - it contains the microprocessor. The CPU is a set of miniaturized circuits that does all the "thinking". It controls the interpretation (arithmetic-logic unit) and execution (control unit) of instructions. The CPU in conjunction with Random Access Memory (RAM) comprise the computer's "brain". The CPU does the "thinking / calculating" while RAM contains the instructions or "memories".

It is the CPU that largely determines the operating speed of the computer. The type of processor on your PC will determine the nature of functions it can carry out and the speed at which instructions are carried out. For example, while a 286 processor would struggle to load Windows 3.1, a 486 processor loads it easily. Additionally, a 286 processor is obviously incapable of running most new software. Pentium processor are now as fast as 200 MHz.

Now the good stuff. Lets read on and want delve into great complexity. Now it’s time to delve deeper into the heart of the computer. The central processing unit or CPU is the "brains" of every computer. On the PC, the CPU is simply a tiny integrated circuit. It is the control center and contains two circuit elements to perform tasks plus several special locations or memory areas called registers which hold instructions.

Registers, located within the CPU chip are temporary storage locations which hold instructions. Secondly, the arithmetic logic unit or ALU is the location within the CPU where basic math and logic operations take place (such as addition and subtraction.) Finally, the control unit is a portion of the CPU which directs all elements of the computer. It does not add or subtract like the ALU, it only directs the activity.

Despite this seeming complexity, a basic fact remains: all digital computers can only add and subtract two numbers: zero and one! Let’s back up a bit. For purposes of digital computer electronics, internally a computer can only respond to two things: on and off - just like a light switch. These electronic states of being might actually be a positive and negative voltage or a high and low voltage stored in a series of transistors etched in silicon on a chip, but to the computer the logic is on or off. Two conditions, that is all.

Back in the human world we can represent these as one and zero (1 and 0). A special branch of mathematics deals with calculations of numbers represented by 1 and 0 which is called binary arithmetic.

We rarely think of 0 as a number since we consider it NOTHING.) To computers ZERO is always a number!!!

To a computer these binary numbers march together in a long string, one after another. Remember, the CPU has only two numbers to work with: 1 and 0.

These eccentricities appear odd, but to the computer they are shortcuts which simplify calculations and keep things to 1’s and 0’s. It is this simple system of on and off (like light switches) which make computers and their odd binary system so FAST!

Bits & Bytes

The IBM PC and its clones generally use 8 bits (electrical pulses) to make up a byte (computer word.) A ninth "odd bit" is used for error checking (parity testing) to make sure the other eight bits are not accidentally erased or lost during storage or use by the computer.

Bits are like alphabet characters and bytes are like the words made up from alphabet characters. Bits and Bytes are used to measure information by the computer.

Bit

Smallest unit of information recognized by the computer. BIT is short for Binary Digit. A Binary Digit can be either a 0 or a 1. Several bits make up a byte.

Byte

A group of 8 BITS. This grouping of adjacent binary digits (bits) is operated on by the computer as a unit. Computers use 1 BYTE to represent 1 character such as a letter of the alphabet, a number, a punctuation mark, a space, etc. A BYTE is also a unit of measure since it represents 1 character.

For example, when the letter "A" is pressed, the keyboard actually sends the following to RAM: 10000001 - a set of 8 bits.

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About the Author: Jide Awe is the Managing Director of Jidaw Systems Limited (MASTERCOMPUTERS), an IT Training and Certification provider that focuses on building IT Careers and publishes http://www.jidaw.com , an IT Career portal