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

Sabtu, 15 November 2008

Programmer

- Create efficient application software for specific processing needs

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

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

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
- haring data and processing among different systems

Hardware Component

- Input/Output devices
- Storage Devices
- CPU
- ALU: arithmetic/logic unit
- CU: control unit
- Interface unit
- Memory : Short-term storage for CPU calculations

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

Software Component

- Applications
- Operating System : API: application program interface, File management, I/O, Kernel : Memory management, Resource scheduling, Program communication, Security
- Network Module

Communications Component

- Hardware
- Communication channels : Physical connections between computer systems, Examples: wire cable, phone lines, fiber optic cable, infrared light, radio waves
- Interface hardware : Handles communication between the computer and the communication channel, Modem or network interface card (NIC)
- Software
- Network protocols: HTTP, TCP/IP, ATAPI

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

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

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

Early History

- 1642: Blaise Pascal invents a calculating machine - 1801: Joseph Marie Jacquard invents a loom that uses punch cards - 1800’s : Charles Babbage attempts to build an analytical engine (mechanical computer), Augusta Ada Byron develops many of the fundamental concepts of programming, George Boole invents Boolean logic. - 1937: Mark I is built (Aiken, Harvard University, IBM) : First electronic computer using relays. - 1939: ABC is built : First fully electronic digital computer. Used vacuum tubes. - 1943-46: ENIAC (Mauchly, Eckert, University of Pennsylvania) : First general purpose digital computer. - 1945: Von Neumann architecture proposed : Still the standard for present day computers. - 1947: Creation of transistor : (Bardeen, Shockley, Brattain, Bell Labs). - 1951: UNIVAC First commercially available computer. Copyright 2003 John Wiley & Sons 3rd Edition, Irv Englander John Wiley and Sons Ó2003 Wilson Wong, Bentley College Linda Senne, Bentley College