2. Assembling an effective, efficient computer system requires an understanding of its relationship to the information system and the organization. The computer system objectives are subordinate to, but supportive of, the information system and the needs of the organization
Describe how to select and organize computer system components to support information system (IS) objectives and business organization needs
Principles of Information Systems, Seventh Edition

3. When selecting computer devices, you also must consider the current and future needs of the information system and the organization. Your choice of a particular computer system device should always allow for later improvements
Describe the power, speed, and capacity of central processing and memory devices
Describe the access methods, capacity, and portability of secondary storage devices
Discuss the speed, functionality, and importance of input and output devices
Identify popular classes of computer systems and discuss the role of each
Principles of Information Systems, Seventh Edition

4. Computer Systems: Integrating the Power of Technology
Special subsystem of an organization’s overall information system
Integrated assembly of devices used to input, process, store, and output data and information
Hardware
Any machinery—most of which use digital circuits—that assists in the input, processing, storage, and output activities of an information system
Principles of Information Systems, Seventh Edition

5. Hardware Components Central processing unit (CPU) Input devices
Output devices
Principles of Information Systems, Seventh Edition

6. Hardware Components (continued)
Communications devices
Primary storage devices
Secondary storage devices
Principles of Information Systems, Seventh Edition

7. Figure 3.1: Computer System Components
Principles of Information Systems, Seventh Edition

8. Hardware Components in Action
Step 1: Fetch instruction
Step 2: Decode instruction
Step 3: Execute instruction
Step 4: Store results
Principles of Information Systems, Seventh Edition

9. Figure 3.2: Execution of an Instruction
Principles of Information Systems, Seventh Edition

10. Processing and Memory Devices: Power, Speed, and Capacity
System unit: houses the components responsible for processing—the CPU and memory
All other computer system devices are linked either directly or indirectly into the system unit housing
Principles of Information Systems, Seventh Edition

11. Processing Characteristics and Functions
Machine cycle time is measured in:
Microseconds (1 millionth of a second)
Nanoseconds (1 billionth of a second)
Picoseconds (1 trillionth of a second)
MIPS (Millions of Instructions Per Second)
Principles of Information Systems, Seventh Edition

12. Processing Characteristics and Functions (continued)
Clock speed: electronic pulses that affect machine cycle time
Hertz (Hz): one cycle (pulse) per second
Megahertz (MHz): millions of cycles per second
Microcode: elementary circuits and logical operations a processor performs when executing instructions
Principles of Information Systems, Seventh Edition

13. Figure 3.3: Clock Speed and the Execution of Microcode Instructions
Principles of Information Systems, Seventh Edition

14. Wordlength and Bus Line Width
Bit: a binary digit (0 or 1)
Wordlength: number of bits the CPU can process at any one time
Bus line: physical wiring that connects the computer system components
Principles of Information Systems, Seventh Edition

15. Physical Characteristics of the CPU
CPU: collection of digital circuits
Electrical current flows through silicon
Moore’s Law: transistor densities on a chip double every 18 months
Superconductivity: property of certain metals that allows current to flow with minimal electrical resistance
Optical processors: computer chips that use light waves instead of electrical current to represent bits
Principles of Information Systems, Seventh Edition

16. Figure 3.4: Moore’s Law
Principles of Information Systems, Seventh Edition

17. Complex and Reduced Instruction Set Computing
Complex instruction set computing (CISC): chip design that places as many microcode instructions into the central processor as possible
Reduced instruction set computing (RISC): chip design that involves reducing the number of microcode instructions built into a chip to an essential set of common microcode instructions
Principles of Information Systems, Seventh Edition

18. Memory Characteristics and Functions: Storage Capacity
Principles of Information Systems, Seventh Edition

19. Types of Memory Random access memory (RAM): temporary and volatile
Types of RAM
EDO (Extended Data Out)
DRAM (Dynamic RAM)
SDRAM (Synchronous DRAM)
Principles of Information Systems, Seventh Edition

20. Types of Memory (continued)
ROM (read-only memory): usually nonvolatile
Types of ROM
PROM (programmable read-only memory)
EPROM (erasable programmable read-only memory)
Cache memory
High-speed memory that a processor can access more rapidly than main memory
Principles of Information Systems, Seventh Edition

21. Figure 3.5: Basic Types of Memory Chips
Principles of Information Systems, Seventh Edition

22. Figure 3.6: Cache Memory
Principles of Information Systems, Seventh Edition

23. Multiprocessing
Multiprocessing: the simultaneous execution of two or more instructions at the same time
Massively parallel processing
Speeds processing by linking hundreds or thousands of processors to operate at the same time, or in parallel
Can coordinate large amounts of data and access them with greater speed
Principles of Information Systems, Seventh Edition

24. Figure 3.7: Massively Parallel Processing
Principles of Information Systems, Seventh Edition

25. Secondary Storage
Secondary storage: offers advantages of nonvolatility, greater capacity, and greater economy
Access methods, storage capacities, and portability required are determined by the information system’s objectives
Principles of Information Systems, Seventh Edition

26. Table 3.1: Cost Comparison for Various Forms of Data Storage
Principles of Information Systems, Seventh Edition

27. Access Methods
Sequential access: retrieval method in which data must be retrieved in order; devices used are called sequential access storage devices (SASDs)
Direct access: retrieval method in which data can be retrieved in any order; devices used are called direct access storage devices (DASDs)
Principles of Information Systems, Seventh Edition

28. Secondary Storage Devices
Magnetic tapes
Magnetic disks
Virtual tape
Optical discs
Principles of Information Systems, Seventh Edition

29. Secondary Storage Devices (continued)
Digital versatile disk (DVD)
Magneto-optical (MO) disks
Memory cards
Flash memory
Expandable storage
Principles of Information Systems, Seventh Edition

30. Enterprise Storage Options
Attached storage
Network-attached storage (NAS)
Storage area network (SAN)
Principles of Information Systems, Seventh Edition

31. Figure 3.12: Storage Area Network
Principles of Information Systems, Seventh Edition

32. Input and Output Devices: The Gateway to Computer Systems
Through input and output devices, people provide data and instructions to computer and receive results from it
Selection of input and output devices depends on organizational goals and information systems objectives
Principles of Information Systems, Seventh Edition

33. Characteristics and Functionality
Data: can be human- or machine-readable
Data entry: process of converting human-readable data into machine-readable form
Data input: involves transferring machine-readable data into the system
Source data automation: involves capturing and editing data where the data is initially created and in a form that can be directly input to a computer
Principles of Information Systems, Seventh Edition

34. Input Devices Personal computer input devices
Keyboard
Mouse
Voice-recognition devices
Digital computer cameras
Terminals
Principles of Information Systems, Seventh Edition

35. Input Devices (continued)
Scanning devices
Optical data readers
Magnetic ink character recognition (MICR) devices
Point-of-sale (POS) devices
Automated teller machine (ATM) devices
Principles of Information Systems, Seventh Edition

36. Input Devices (continued)
Pen input devices
Light pens
Touch-sensitive screens
Bar-code scanners
Radio-frequency identification (RFID)
Principles of Information Systems, Seventh Edition

37. Output Devices Display monitors Liquid crystal displays (LCDs)
Active-matrix
Passive-matrix
Principles of Information Systems, Seventh Edition

38. Output Devices (continued)
Organic light-emitting diodes (OLEDs)
Printers and plotters
Computer output microfilm (COM) devices
Music devices
Principles of Information Systems, Seventh Edition

39. Computer System Types, Selecting, and Upgrading
Computers can be classified as either special purpose or general purpose
Special-purpose computers: used for limited applications by military and scientific research groups
General-purpose computers: used for a wide variety of applications
Principles of Information Systems, Seventh Edition

40. Computer System Types Handheld computers Portable computers
Thin client
Desktop computers
Principles of Information Systems, Seventh Edition

41. Computer System Types (continued)
Workstations
Servers
Mainframe computers
Supercomputers
Principles of Information Systems, Seventh Edition

42. Selecting and Upgrading Computer Systems
Hard drive considerations
Main memory considerations
Printer considerations
DVD burners
Principles of Information Systems, Seventh Edition

43. Summary
Hardware: machinery that assists in the input, processing, storage, and output activities of an information system
Hardware components include central processing unit (CPU), input and output devices, communications devices, primary storage devices, and secondary storage devices
Random access memory (RAM): temporary and volatile
Read-only memory (ROM): usually nonvolatile
Principles of Information Systems, Seventh Edition

44. Summary (continued)
Multiprocessing: simultaneous execution of two or more instructions at the same time
Sequential access: records must be retrieved in order
Direct access: records can be retrieved in any order
Examples of secondary storage devices: magnetic tapes and disks, optical disks, and DVDs
Enterprise storage options: attached storage, network- attached storage (NAS), and storage area network (SAN)
Principles of Information Systems, Seventh Edition

45. Summary (continued)
Examples of input devices: keyboards, mice, voice- recognition devices, terminals, scanning devices, and touch-sensitive screens
Examples of output devices: display monitors, liquid crystal displays (LCDs), printers, and plotters
Computers can be classified as either special purpose or general purpose
Computer system types: handheld computers, portable computers, desktop computers, workstations, servers, etc.
Principles of Information Systems, Seventh Edition