Computer Hardware Basic Computer Concepts Data Representation and Digital Electronics  Data Representation  makes it possible to convert letters, sounds, and images into electrical signals  Digital Electronics  makes it possible for a computer to manipulate simple “on” and “off” signals to perform complex tasks

Computer Hardware Basic Computer Concepts Digital Data Representation Why are computers digital ?  Digital Device  works with discrete -distinct or separate - data or digits, such as 1 and 0  Analog Device  works with continuous data  Computers are digital because computer designers have found it to be a relatively simple, dependable, and adaptable technology. A digital computer is a simpler technology than an analog computer. Most computers use the simplest type of digital technology, their circuits have only two possible states.

Computer Hardware Basic Computer Concepts Digital Data Representation How can a computer represent numbers using bits ?  Computers represent numeric data using the binary number system, also called “base 2” Numeric Data  the numbers that might be used in arithmetic operations  Binary Number System  has only two (2) digits : 0 and 1 allows computers to represent virtually any number simply by using 0s and 1s conveniently translates into electrical “on” and “off” signals

Computer Hardware Basic Computer Concepts Digital Data Representation How can a computer represent words and letters using bits ?  Character Data  consists of letters, symbols and numerals that will not be used in arithmetic calculations  A digital computer uses a series of bits to represent letters, characters, and numerals. ASCII  pronounced as “ ASK ee” stands for American Standard Code for Information Interchange requires only seven bits for each character  Extended ASCII  a superset of ASCII uses eight bits to represent each character provides codes for 128 additional characters

Computer Hardware Basic Computer Concepts Digital Data Representation How can a computer represent words and letters using bits ?  EBCDIC  pronounced as “EB seh dick” stands for Extended Binary Coded Decimal Interchange Code an alternative 8-bit code usually used by IBM mainframe computers  UNICODE  pronounced as “YOU ni code” provides codes for 65,000 characters and makes use of 16 bits

Computer Hardware Basic Computer Concepts Digital Data Representation How does a computer convert sounds and pictures into codes ?  A computer must somehow digitize colors, notes, and instrument sounds into 1s and 0s, in order to work with sounds and pictures. Computers convert colors and sounds into numbers, which can be represented by bits. A red dot on your computer screen might be represented by 1100, a green dot by 0010.

Computer Hardware Basic Computer Concepts Digital Data Representation When a computer works with a series of 1s and 0s, how does it know which code to use?  All of the things that computer works with is stored in files as a long series of 1s and 0s. The computer needs to know whether to interpret those 1s and 0s as ASCII code, binary numbers, or the code for a picture or sound. Most computer files contain a file header with information on the code that was used to represent the file data, to avoid confusion. A computer can now tell how a file’s contents were coded by reading the header information.

Computer Hardware Basic Computer Concepts Digital Electronics How can I tell the difference between bits and bytes?  bit  binary digit can be further abbreviated as a lowercase “b”  byte  composed of eight (8) bits usually abbreviated as an uppercase “B”  nibble  composed of four (4) bits a halfway between a little bit and a big byte  Storage space is usually expressed in bytes while transmission speeds are expressed in bits.

Computer Hardware Basic Computer Concepts Digital Electronics How does a computer store and transport all of those bits ?  Bits take the form of electrical pulses that can travel over circuits. The circuits, chips, and mechanical components forming a computer are designed to work with bits. These components are housed within the computer’s system unit.

Computer Hardware Basic Computer Concepts Digital Electronics How do chips fit together to make a computer?  Motherboard  also known as main board the computer’s main circuit board houses all essential chips and provides connecting circuitry between them  Some chips are permanently soldered in place, while other chips are plugged into special sockets and connectors. The chips might be gathered together on a separate small circuit board, which can then be plugged into a special slot-like connector.

Computer Hardware Basic Computer Concepts Microprocessor Basics  Microprocessor  sometimes known as processor an integrated circuit designed to process instructions the most significant component of computer and usually the most expensive single component executes instructions that are provided by a computer program  Instruction Set  list of instructions that a microprocessor can perform hardwired into the processor’s circuitry comprising of basic arithmetic and logical operations, fetching data, and clearing registers  Memory  is the electronic that holds place for instructions and data which the microprocessors can reach quickly

Computer Hardware Basic Computer Concepts Today’s Microprocessors Which companies produce most of today’s popular microprocessors ?  Intel  world’s largest chipmaker and supplies a sizeable percentage of the microprocessors that power personal computers introduced the world’s first microprocessor, the 4004, during 1971  AMD (Advanced Micro Devices)  Intel’s chief rival in the PC chip market produces microprocessors that work just like Intel's chips, but a lower price

Computer Hardware Basic Computer Concepts Today’s Microprocessors Which of the microprocessors is the best ?  Intel  Original Pentium : 1993 Pentium II : 1997 Pentium III : 1999 Pentium IV: 2000 Itanium : 2001 Celeron processors : Intel’s budget model  AMD  Athlon processors : Direct competitors to Intel’s Pentium line Duron processor : AMD’s budget model  The microprocessor that’s “best” for you depends on your budget and the type of work and play that you plan to do.