Chapter 2 IT Foundation Data: facts about objects Store data in computer: – binary data – bits – bytes Five types of data

I. Five Types of Data P.40 Figure 2.2 Number (.txt,.xls) Text (.txt,.xls) Image (.bmp) Sound (.wav) Video (.avi) Storage space (Binary data, Bit, Byte) Multimedia

Number: Base 2 numbers (binary) Text: character set –ASCII (American Standard Code for Information Interchange), e.g., A 65, B 66. –EBCDIC (Extended Binary Coded Decimal Interchange Code), for IBM Mainframe. –Different countries may use different character set.

Picture: 2 formats –Pixel format (.bmp, paintbrush) binary number -> dot for color resolution - dpi (dots per inch) & storage space –Vector format (autocad) Engineering drawings Mathematical description -> less storage space

Sound:.wav –two components of sound: volume and pitch –two ways to digitize sound Sampling: take observations of two values (volume and pitch) several times per second MIDI (Musical Instrument Data Interchange): use music keyboard to digitize music Advantages of MIDI: less storage space, easy to modify Disadvantages of MIDI: complicated hardware, machine-dependant

Video: –Tremendous amount of data (100 CD’s for one-hour movie) –Data compression

II. Hardware Components of Computer System p.45 Input Output Processor Secondary Storage

Input (P.50 - P.51) –Keyboard –Pointing devices: mouse, light pen, touch screen –Scanner –Pen-based systems: pen & software for converting handwriting –Sound: microphone and sampler –Voice recognition (expensive) –Video capture board: digitize video

Output (P.51 - P.53) –Monitor resolution: # of pixels & colors video card & video RAM –Printer laser ink-jet dot-matrix

Process System (p.46 – p.48): –Processor: CPU (Central Processing Unit): carries out instructions; Registers –RAM (Random Access Memory) –Device controllers –Speed vs. Internal Clock Speed: MIPS Internal clock: 100MHz, 450MHz Speed  clock speed (# of clock cycles per instruction, 486D50 is slower than Pentium 50) Comparable only for the same manufacturer and the same family

–Speed depends on other components Data bus Access time and capacity of RAM Parallel processors –Price differential PC - the lowest $/MIPS Use for different purposes (e.g., IBM Mainframe for multiple users)

Secondary Storage (P.53-P.55) –hard drive –floppy disk drive –tapes (backup) –optical drive CD-ROM (650 megabytes) WORM (Write Once Read Many) Erasable DVD (Digital Video Disk) –Solid State/RAM (keep data when power is off)

III. Software Programs Systems software –Operating systems –Utilities –Language translators Applications

1.Operating Systems (p.55) A program that acts as an intermediary between users and hardware Three functions of OS –allocation and assignment of resources –scheduling of jobs –monitoring activities (security, usage)

Specific operating systems –VMS (DEC VAX) –MVS (IBM Mainframe) –UNIX (machine-independent) –OS/2 (IBM PC, robust and memory- intensive) –Windows 98 (PC) –Windows NT (workstation, network server) GUI (Graphical User Interface)

Multitasking (Prob.4) –Users can run more than one job at the same time –OS rotates jobs, not exactly run them at the same time –Reduce total processing time (OS coordinates all components of computer system) –Prevent users from changing data at the same time.

2. Browser and Web Server (p.56-p.57) Browser: –Read incoming files, recognize data type, display data as instructed –Add-ins –Internal programming language –Platform free Web server: –Monitor Internet and deliver the requested files –Selecting hardware: scalability, easy backup, and easy maintenance. –Split into separate pieces.

3. Applications DBMS: Access Calculation: Excel Writing: Word Presentation: PowerPoint Communication: (Outlook Express) Scheduling: Microsoft Outlook