A.Abhari CPS1251 Topic 1: Introduction to Computers Computer Hardware Computer components Connecting Computers Computer Software Operating System (OS) Running a High-level Language Problem Solving with Computers Software Development Method

A.Abhari CPS1252 Computer components Central Processing Unit Memory Input/output devices Secondary storage

A.Abhari CPS1253 Computer Components

A.Abhari CPS1254 CPU

A.Abhari CPS1255 CPU Arithmetic/logic unit (ALU) Performs arithmetic operations (+,-,...) and logical operations (,...) Control unit (CU) Decodes machine instructions and tells other components the required operations Registers store current instruction and values

A.Abhari CPS1256 Memory A collection of cells Each cell has an address and a value Random Access Memory (RAM) Cells can be accessed randomly Ram is volatile All data stored in binary format Bit, byte and word are the unit of data

A.Abhari CPS1257 CPU-Memory Interaction 0LDA 14 1ADD 15 2STA 14 3HLT ….…… Assume a is stored in 14 and b is stored in 15 a= a + b Result Program Fetch-execute cycle

A.Abhari CPS1258 Input/output Devices Text-based and GUI-based interaction Scanners, Touch screens Monitor, printer, speakers Secondary Storage Floppy disk, CD (680 MB), DVD (4.717 GB), Tape, Hard disk File, Directory, Subdirectory, Folder

A.Abhari CPS1259 Hard Disk Drive Basics

A.Abhari CPS12510 Connecting Computers Local Area Network (LAN) Wide Area Network (WAN) Internet World Wide Web (WWW)

A.Abhari CPS12511 Computer Software Operating System (OS) Part of OS is stored on Read Only Memory (ROM) OS is responsible for directing all computer operations and resources Command line interface (Unix) Graphical user interface (Windows)

A.Abhari CPS12512 Computer Software Application Software ( Word, Excel, etc.) Computer Languages Low level languages (machine language) High level language (C, Java, Fortran, …)

A.Abhari CPS12513 Running a High-level Language Generating a source file (editor) => tst.c Translating to machine code (compiler) =>tst.obj Linking the object file with other object files (linker) =>tst.exe Copying the executable file into memory (loader) Integrated Development environment (IDE) combines all of these steps

A.Abhari CPS12514 Problem Solving with Computers (Software Development Method) 1- Specify the problem requirement 2- Analyze the problem (input, output, additional requirements). Modeling the problem (abstraction) 3- Design the algorithm to solve the problem (top-down design or divide and conquer) 4- Implement the algorithm=> changing the algorithm to a programming language

A.Abhari CPS12515 Problem Solving with Computers (Software Development Method) 5- Test and verify the complete program, running the program several times with different data sets 6- Maintain and update the program, removing undetected errors ** Failure is part of the process **