MELJUN CORTES Basic structure of computer hardware and software

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Basic Structure of Computer Hardware and Software

Computer Organization and Assembly Language

What is a Digital Computer?

Ø A digital computer is a fast electronic calculating machine that accepts digitized input information, processes it according to a list of internally stored instructions, and produces the resulting output information.




Types of Computers

Ø Personal Computers

Ø Workstations

Ø Mainframes

Ø Supercomputers




Functional Units of a Computer

Arithmeticand

Logic

Control

Processor

Input

Output

I/O

Memory




Input Unit

Ø The Input Unit accepts coded information from human operators or from other computers.

Ø Examples:v keyboard, joystick, mouse, input pen,

touch screen, trackball, scanner, bar code readers, microphone, floppy disks, magnetic tapes, compact disks




The Memory Unit –Primary Storage

Ø Primary Storage or Main Memory. This is where programs are stored during their execution. The MM is a fast memory capable of operating at electronic speeds.

Ø The information in MM is often processed in groups of fixed size called words.




The Memory Unit –Primary Storage

.

.

.

0

1

2

4,194,302

4,194,303

Address of 1stMemory Location

MemoryLocation

To provide easy access to any word in MM, a distinct address is associated with each word location. Addresses are numbers that identify successive locations.




Main Memory Divisions

Ø MM is subdivided into the following:

v Input Storage Area

v Working Storage Space

v Output Storage Area

v Program Storage Area




Memory Unit – Secondary Storage

Ø Secondary Storage or Auxiliary Storage.

v This is used when large amounts of data have to be stored (on a more permanent basis), particularly if some of the data need not be accessed very frequently.




Processing Unit

Ø Also called the Central Processing Unit(CPU) or Central Processor.

Ø It contains a number of high-speed (10 times faster than MM) storage elements called registers that are used for temporary storage of frequently used operands.

Ø The CPU is composed of the Arithmetic-Logic Unit (ALU) and the Control Unit(CU).




Output Unit

Ø It sends processed results to the outside world.

Ø Examples:

v Display screens, printers, plotters, modems, microfilms, synthesizers, high-tech blackboards, film recorders




Basic Operation of a Computer

Ø The operation of a computer can be summarized as follows:

1. The computer accepts information.2. Information stored in the memory is

fetched, under program control, into an arithmetic and logic unit, where it is processed.

3. Processed information leaves the computer through an output unit.

4. All activities inside the machine are directed by the control unit.




Basic Concepts of Computer Architecture

Ø Computer Architecture is the design of computers, including their instruction sets, hardware components, and system organization.




Types of Programming Language

Ø The different types of programming languages are as follows:

v Machine Languagev Assembly Languagev High-level Languagev 4GL Language




Machine Language

Ø The natural or primitive language that the computer actually understands. This programming language consists of 0’s and 1’s which makes programming very difficult.




Assembly Language

Ø A programming language that uses “abbreviations” or mnemonics in place of binary patterns in order to make the task of programming easier.

Ø An assembler is used to translate assembly language mnemonics into machine language.




High-Level Language

Ø A programming language that uses English-like commands or instructions. High-level languages are the easiest to use and contains many complicated or advanced instructions.

Ø A compiler is used to translate high-level language instructions into machine language.




Fourth Generation Language

Ø A fourth-generation programming language (or 4GL) is a programming language designed with a specific purpose in mind such as the development of commercial business software.

Ø All 4GLs are designed to reduce:v programming effort. v the time it takes to develop software. v the cost of software development.




Advantages of High-Level Languages

Ø Advantages of using high-level languages over low-level languages:

1. Easy to Learn2. Predefined Functions3. Portability




Advantages of Low-Level Languages

Ø Advantages of using low-level languages over high-level languages:

1. Compact Code2. Speed3. Flexible

Technology

MELJUN CORTES Basic structure of computer hardware and software