CHAPTER 1 OVERVIEW OF COMPUTER AND PROGRAMMING 1.1 Electronic Computer Then and Now 1.2 Computer Hardware 1.3 Computer Software 1.4 The Software Development Method 1.5 Applying the Software Development Method

1.1 Overview of Computer Then and Now 1 st electronic computer – 1930 Dr John Atanasoff and Clifford Berry Iowa State University ENIAC General purpose electronic digital computer University of Pennsylvania 30 tons, 30 to 50 foot space Used – compute ballistic table, predict the weather, make atomic energy calculations

1.1 Overview of Computer Then and Now (Cont..) Computer category Microcomputer Workstations Minicomputers Mainframe Supercomputer Elements of computer Hardware – equipment / devices Software programs that enable us to solve problem with a computer by providing it with lists of instruction to perform. Written by programmers

Components 1.Main memory RAM (Random Access Memory) - Volatile ROM (Read Only Memory) – Non-volatile 2.Secondary memory Hard disk, floppy disk, magnetic disk, CD 3.Central Processing Unit (CPU) Control Unit (CU) Arithmetic Logic Unit (ALU) 4.Input Devices Keyboard, mouse, microphone, 5.Output Devices Monitor, speaker, printer 1.2 Computer Hardware

2 types: Operating system Application software Operating system Stored permanently –ROM Example: – Command line Interface – UNIX, MS-DOS, VMS – Graphical User Interface – Macintosh OS, Windows 98/ XP, Windows NT Application Software Develop to assist a computer user in accomplishing specific tasks. Example : word processing, spreadsheet, Adobe 1.3 Computer Software

1.3 Computer Software (Cont..) Machine Language /Low-level Language Binary number – 0,1 Computer understand High-level Language / Programming Language Example: C, C++, Visual Basic, Cobol, Fortran Compiler / interpreter The language translation software that convert a programmer’s statement to binary form Language syntax Rules governing its word usage and punctuation.

Six (6) Software Development Method 1.Specify the problem requirement Understanding required for its solution 2.Analyze the problem Identify input, process, output 3.Design the algorithm to solve a problem Develop a list of steps called algorithm Pseudocode, Flowchart, N-S Diagram, Decision Table 4.Implement the algorithm Convert algorithm to programming language 5.Test and verify the completed program Compile  Run 6.Maintain and update the program 1.4 The Software Development Method

1.Problem Mengira Luas Segiempat 2.Analysis Input : panjang, lebar Proses: Luas = panjang x lebar Output : Luas 3.Design Algorithm Pseudocode 4.Implementation 1.5 Applying the Software Development Method Start get panjang, lebar Luas = panjang * lebar print Luas Stop #include int main() {int panjang, lebar, Luas; scanf (“%d %d”, &panjang, &lebar); Luas = panjang * lebar; printf (“%d”, Luas); return 0; }