1Computer.Systems

1Computer.Systems

• 1. CHAPTER 1:Computer Systems CHAPTER 1: Computer Systems The Architecture of Computer Hardware and Systems Software: An Information Technology Approach 3rd Edition, Irv Englander John Wiley and Sons 2003 Wilson Wong, Bentley College Linda Senne, Bentley College
• 2. Typical Computer Ad Chapter 1 Computer Systems 1-2 Typical Computer Ad §Is the computer fast enough to run necessary programs? §Is the computer cost-effective? §Will it be obsolete in 6 months?
• 3. Why Study Computer Architecture? Chapter 1 Computer Systems 1-3 Why Study Computer Architecture? §User §Understand system capabilities and limitations §Make informed decisions §Improve communications with information technology professionals §Systems Analyst §Conduct surveys, determine feasibility and define and document user requirements §Specify computer systems to meet application requirements §Programmer §Create efficient application software for specific processing needs
• 4. Why Study Computer Architecture? Chapter 1 Computer Systems 1-4 Why Study Computer Architecture? §System Administrator / Manager §Install, configure, maintain, and upgrade computer systems §Maximize system availability §Optimize system performance §Ensure system security §Web Designer §Optimize customer accessibility to Web services §System administration of Web servers §Select appropriate data formats §Design efficient Web pages
• 5. Input-Process-Output Model (IPO) Chapter 1 Computer Systems 1-5 Input-Process-Output Model (IPO) •Input: keyboard, mouse, scanner, punch cards •Processing: CPU executes the computer program •Output: monitor, printer, fax machine •Storage: hard drive, optical media, diskettes, magnetic tape
• 6. Architecture Components Chapter 1 Computer Systems 1-6 Architecture Components §Hardware §Processes data by executing instructions §Provides input and output §Software §Instructions executed by the system §Data §Fundamental representation of facts and observations §Communications §Sharing data and processing among different systems
• 7. Hardware Component Chapter 1 Computer Systems 1-7 Hardware Component §Input/Output devices §Storage Devices §CPU §ALU: arithmetic/logic unit §CU: control unit §Interface unit §Memory §Short-term storage for CPU calculations
• 8. Typical Personal Computer System Chapter 1 Computer Systems 1-8 Typical Personal Computer System
• 9. CPU: Central Processing Unit Chapter 1 Computer Systems 1-9 CPU: Central Processing Unit §ALU: arithmetic/logic unit §Performs arithmetic and Boolean logical calculations §CU: control unit §Controls processing of instructions §Controls movement of data within the CPU §Interface unit §Moves instructions and data between the CPU and other hardware components §Bus: bundle of wires that carry signals and power between different components
• 10. Memory Chapter 1 Computer Systems 1-10 Memory §Also known as primary storage, working storage, and RAM (random access memory) §Consists of bits, each of which hold a value of either 0 or 1 (8 bits = 1 byte) §Holds both instructions and data of a computer program (stored program concept)
• 11. Software Component Chapter 1 Computer Systems 1-11 Software Component §Applications §Operating System §API: application program interface §File management §I/O §Kernel pMemory management pResource scheduling pProgram communication pSecurity §Network Module
• 12. Communications Component Chapter 1 Computer Systems 1-12 Communications Component §Hardware §Communication channels pPhysical connections between computer systems pExamples: wire cable, phone lines, fiber optic cable, infrared light, radio waves §Interface hardware pHandles communication between the computer and the communication channel pModem or network interface card (NIC) §Software §Network protocols: HTTP, TCP/IP, ATAPI
• 13. Computer Systems Chapter 1 Computer Systems 1-13 Computer Systems All computer systems, no matter how complex, consists of the following: §At least one CPU §Memory to hold programs and data §I/O devices §Long-term storage
• 14. Protocols Chapter 1 Computer Systems 1-14 Protocols §Common ground rules of communication between computers, I/O devices, and many software programs §Examples §HTTP: between Web servers and Web browsers §TCP/IP: between computers on the Internet and local area networks §ATAPI: between a CPU and CD-ROMs
• 15. Standards Chapter 1 Computer Systems 1-15 Standards §Created to ensure universal compatibility of data formats and protocols §May be created by committee or may become a de facto standard through popular use §Examples: §Computer languages: Java, SQL, C, JavaScript §Display standards: Postscript, MPEG-2, JPEG, GIF §Character set standards: ASCII, Unicode, EBCDIC §Video standards: VGA, XGA, RGB