Slide 1:Chapter 1 Introduction


Slide 2:After reading this chapter, the reader should be able to: OBJECTIVES


Slide 3:THE COMPUTER AS A BLACK BOX 1.1


Slide 4:Figure 1-1 Data processor model Data processor model


Slide 5:Figure 1-2 Programmable data processor model Programmable Data processor model Computers – general-purpose machines


Program :Program A program is a set of instructions that tells the computer what to do with data. written in a computer language.


Slide 7:Figure 1-3 Same program, different data Same program, different data


Slide 8:Figure 1-4 Same data, different programs Same data, different programs


Slide 9:von NEUMANN MODEL 1.2


von Neumann Model :von Neumann Model Every computer today is based on the von Neumann Model. It is based on 3 ideas: Four subsystems Stored Program Concept Sequential Execution of Instructions


Slide 11:Figure 1-5 von Neumann model Four subsystems: Memory – the storage area of programs and data. ALU – arithmetic/logic operations take place Control Unit – control Memory, ALU, and I/O I/O – accept input data/send output data


Input/Output Subsystem :Input/Output Subsystem The definition is very broad;it includes the secondary storage devices. Disk – stores data and programs for processing


Stored Program Concept :Stored Program Concept The von Neumann model states thatthe program must be stored in memory. The memory of modern computershosts both a program its corresponding data


Sequential Execution of Instructions :Sequential Execution of Instructions A program is made of a finite number of instructions. The control unit fetches one instruction from memory interpret it execute it The instructions are executed one after another.


Slide 15:COMPUTER HARDWARE 1.3


Slide 16:ALU Control unit Registers


Slide 17:DATA 1.4


Storing Data :Storing Data Store data in the form of an electrical signal, specially its presence or absence. This implies that a computer can store data in one of two states. Binary number system


Data organization :Data organization Although data should be stored only in one form (a binary pattern) inside a computer,data outside a computer can take many forms. Data come in different forms: Numbers Text Images Audio Video


Slide 20:COMPUTER SOFTWARE 1.5


Requirements of von Neumann model :Requirements of von Neumann model The programs must be stored in memory. (Fig. 1.6) The programs must be a sequence of instructions. (Fig. 1.7)


Slide 22:Figure 1-6 Program and data in memory Fig. 1.6


Slide 23:Figure 1-7 Program made of instructions Fig. 1.7 Program made of instructions


Algorithm :Algorithm A programmer should first solve the problem in a step-by-step manner and then try to find the appropriate sequence of instructions that solves the problem. The step-by-step solutionis called an algorithm


Operating Systems :Operating Systems An operating system originally worked as a manager to facilitate access of the computer components for a program.


Slide 26:HISTORY 1.6


Before 1950 :Before 1950 Mechanical machines (before 1930) Early electronic computers (1930-1950) ENIAC (Electronic Numerical Integrator and Calculator)first general-purpose, totally electronic computerUniversity of Pennsylvania, 1946


1950 :1950 The preceding computers used memory only for storing data. EDVACthe first computer based on von Neumann’s idea,University of Pennsylvania,1950


Computer generations(1950-present) :Computer generations(1950-present) 1st generation (1950-1959)vacuum tubes 2nd generation (1959-1965)transistors, High-level languages(FORTRAN, COBOL) 3rd generation (1965-1975)IC(Integrated Circuit), Minicomputer, software industry was born 4th generation (1975-1985)VLSI, microcomputer 5th generation (1985-)laptop and palmtop computer


Microcomputer :Microcomputer Microcomputers are designed to be used by individuals, whether in the form of PCs, workstations or notebook computers. A microcomputer contains a CPU on a microchip (the microprocessor), a memory system (typically ROM and RAM), a bus system and I/O ports, typically housed in a motherboard.