1. An Introduction to Hardware, Software, and the Internet 9/21/2015 1-1

2. 1-2 Objectives: Get an overview of the main hardware components and terms: CPU, memory, peripheral devices Learn about software: operating system and application software Get an idea of how information is stored in computer memory Learn basic facts about the Internet 9/21/2015

3. 1-3 Hardware The CPU (Central Processing Unit) is made of millions of semiconductor devices, called transistors, etched into a silicon chip. Transistors are combined to form logical devices called gates. All digital electronics is basically made up of gates. 9/21/2015

4. 1-4 Gates AND gateOR gateNOT gate 9/21/2015

5. 1-5 Example: XOR Circuit OR (NOT A) AND B 9/21/2015

6. 1-6 RAM, CPU, Bus CPU Memory (RAM) Data bus Address bus Registers Memory (ROM) 9/21/2015

7. 1-7 CPU RAM (SIMMs) Extension slots ROM Motherboard 9/21/2015

8. 1-8 Hardware Terms CPU — Central Processing Unit RAM — Random-Access Memory  “random-access” means the CPU can read directly from and write to any memory location  holds both data and CPU instructions ROM — Read-Only Memory  holds initialization and hardware diagnostic programs Peripheral devices (secondary storage, input/output) 9/21/2015

9. 1-9 CPU In personal computers, the CPU is a microprocessor, contained on one chip. The CPU speed is measured in GHz (gigahertz, billions of clock cycles per second) or, in older computers, in MHz (megahertz, millions of cycles). A CPU instruction takes one or several clock cycles. Heinrich Rudolf Hertz 9/21/2015

10. 1-10 RAM 1 KB (kilobyte) = 1024 bytes 1 MB (megabyte) = 1024 · 1024 bytes 1 GB (gigabyte) = 1024 · 1024 · 1024 bytes 1 TB (terabyte) = 1024 gigabyes 1 PB (petabyte) = 1024 terabyes 0 0 1 0 1 1 0 1 bit 0 bit 7 2 20  10 6, a million 2 30  10 9, a billion 2 10 1 byte = 8 bits 9/21/2015

11. 1-11 Secondary Storage Hard disk: 100 - 1000 GB CD-ROM: 700 MB A file is a software concept Flash drive: 1 - 8 GB 9/21/2015

12. 1-12 I/O Devices Monitor and video adapter Keyboard, mouse or touch pad Sound card, speakers, microphone Internet adapter, wi-fi (wireless) adapter D/A (digital-to-analog) and A/D (analog-to- digital) converters Scanners, digital cameras, printers 9/21/2015

13. 1-13 Software Layers Device drivers Operating system Applications BIOS, firmware 9/21/2015

14. 1-14 Software Terms Operating system  a program that maintains the file system, dispatches applications, and provides other system-level services Console application  a program with simple text user interface GUI — Graphical User Interface  graphics, menus, buttons, icons, etc. OOP — Object-Oriented Programming 9/21/2015

15. 1-15 Software Engineers are Able To: Absorb and use emerging technical information Create sound software system architectures Understand and devise effective algorithms Be proficient with the syntax and style of programming languages Diagnose and correct programming errors Continued... 9/21/2015

16. 1-16 Software Engineers are Able To: Use software development tools and documentation Find and utilize reusable software components Design and implement friendly user interfaces Uphold the highest standards of professional ethics 9/21/2015

17. 1-17 Integers are represented in binary (base 2) Java uses 4 bytes for an integer (int data type) Numbers In Memory 000000000 100000001 200000010 300000011... 25511111111 9/21/2015

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19. 1-19 For signed numbers, the most significant bit indicates the sign: Negative numbers are represented in two’s-complement form 00000000 00000000 00000000 00010001 Numbers In Memory (cont’d) Sign bit 116 17 + 111111111 11111111 11111111 11101110 Sign bit -17 17 + (-17) = 2 32 = 0 9/21/2015

20. 1-20 Numbers in Memory (cont’d) Real numbers are represented as floating- point numbers (similar to scientific notation) with a sign, binary mantissa (fractional part), and binary exponent. Java uses 8 bytes (64 bits) for a “double” (that is, double-precision) floating-point number. double’s range is from -1.8  10 308 to 1.8  10 308 (but precision is only 14 significant digits) 9/21/2015

21. 1-21 Characters Unicode associates characters with numbers (2 bytes represent a character). ASCII (American Standard Code for Information Interchange) is a subset comprising the first 128 codes of Unicode:  32  ‘A’ - ‘Z’ 65 - 90  ‘0’ - ‘9’ 48 - 57  ‘a’ - ‘z’ 97 - 122 The first 32 codes are control codes (Carriage Return, Newline, Tab, etc.). 9/21/2015

22. 1-22 Memory Addresses in a Computer While a program is running, data is temporarily stored in the RAM of a computer, or written to virtual memory (the page file) Memory addresses are typically referenced in hexidecimal, which is a number system in base 16, 0-9 A-F 9/21/2015

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24. 1-24 The Internet A network of interconnected computers that share common communication protocols, TCP/IP TCP: Transmission Control Protocol IP: Internet Protocol 9/21/2015

25. 1-25 The Internet Layers Internetworking: routing and forwarding data (IP) Transport: delivering data reliably and securely (TCP) Applications: telnet, www, e-mail, IM, FTP, Voice Network technology (switches, adapters, routers) 9/21/2015

26. 1-26 The Internet Terms Browser  provides convenient way to download and display information from the Internet Search engine  indexes and helps find the Internet documents that contain specified keywords and phrases Portal  a large popular web site that has a collection of links arranged by category 9/21/2015

27. 1-27 The Internet Terms (cont’d) Host  a computer connected to a network Server  a computer on a network that provides a particular service (e.g., e-mail server) URL  Uniform Resource Locator, an address of a document or a resource on the Internet 9/21/2015

28. 1-28 The Internet Terms (cont’d) Host  a computer connected to a network Server  a computer on a network that provides a particular service (e.g., e-mail server) URL  Uniform Resource Locator, an address of a document or a resource on the Internet 9/21/2015

29. 1-29 Java Programming Language: Java was developed in the early 1990’s by James Gosling of Sun Microsystems Popular because Java programs could easily be delivered over the internet. Java Virtual Machine “Write once, run anywhere.” 9/21/2015

30. 1-30 Review: Describe the outputs of the following circuits:

31. 1-31 Review: What are CPU, RAM, and ROM?

32. 1-32 Review (cont’d): : Name six I/O devices.

33. 1-33 Review (cont’d): Is a device driver a hardware or a software entity? 9/21/2015

34. 1-34 Review (cont’d): Describe the main difference between a console and a GUI application. 9/21/2015

35. 1-35 Review (cont’d): Is a file a hardware or a software concept? 9/21/2015

36. 1-36 Review (cont’d): What is the 8-bit binary representation for 604? What is the hexidecimal representation for 604? 9/21/2015

37. 1-37 Review (cont’d): In Java, how many bytes are used to represent an integer (type int)? In Java, how many bytes are used to represent a floating point number (type double)? 9/21/2015

38. 1-38 Review (cont’d): What does TCP/IP stand for? 9/21/2015 Transmission Control Protocol Internet Protocol