1. Chapter 3
Computer Hardware

2. II. A Brief History of Computer Hardware
Without computers many technological achievements would not have been possible:
Counting with fingers/toes
Blaise Pascal, 1642 – invented the first mechanical adding machine

3. A Brief History of Computer Hardware
Herman Hollerith – Hollerith’s Punch Card system to record census data in late 1880’s; 1911 – merged with competitor to form IBM
ENIAC (Electronic Numerical Integrator and Calculator), 1946 – the world’s first electronic digital computer

4. II. A Brief History of Computer Hardware
1950’s – Transistors were invented and replaced tubes
1958 – Integrated Circuit (“chip”) was invented
1970’s – 1980’s
Further miniaturization of circuits
Apple Computer and IBM PC

5. III. Types of Computer Systems
Computers come in a variety of sizes, shapes, and computing capabilities –
Mainframes
Midrange (obsolete due to powerful microcomputers)
Microcomputers

6. IV. Microcomputer Systems (Personal Computer)
The most important category for businesses and consumers, exceeds the power of many mainframes
Workstations – support mathematical and graphical demands
Network Servers – support telecommunications and resource sharing
Computer Terminals – any device that allows access to a computer

7. IV. Microcomputer Systems (Personal Computer)
Network Computers – designed specifically for use with networks and the Internet; low TCO (total cost of ownership)
Information Appliances – Web-enabled devices for accessing information from anywhere – cell phones, PDAs, handheld PCs

8. Corporate PC Criteria Why laptops instead of desktops?
Why would a change in OS be disruptive?
What are the strengths vs. risks of cabled vs. wireless PCs?

9. V. Midrange, Mainframe, and Supercomputer Systems
Midrange Systems – popular as Network Servers; disappearing due to microcomputers
Mainframe Systems – large, fast, and powerful, used for high transaction processing and complex computations; used by corporations and government agencies
Supercomputers – extremely powerful, extremely high speeds and massive numeric computations

10. V. Midrange, Mainframe, and Supercomputer Systems
The Next Wave of Computing – minisupercomputers; connecting all the power of unused desktops in an organization
Distributed (Grid) Computing – parallel computing over a network
Advantages – purchase nodes as a commodity, economies of scale
Disadvantages – untrustworthy calculations, lack of centralized control

11. The Computer System

12. VII. Moore’s Law
Moore’s Law 1965 – the number of transistors on a chip will double every months – essentially, the power or speed of a computer will double every months
The Price would halve in that same time, which has also proven to be true
Recent statistics indicate this time has decreased to 12 months

13. Section 2 Computer Peripherals: Input, Output, and Storage Technologies
Peripheral - a generic name for all input, output, and secondary storage devices not part of the CPU (basically, what is connected to the outside of the computer)

14. Input Devices – keyboards, mice, light pens, trackballs, touch screens
II. Input technologies
Input Devices – keyboards, mice, light pens, trackballs, touch screens
Speech Recognition Systems – understands spoken commands/words
Discrete Speech Recognition – speak each word separately
Continuous Speech Recognition – recognizes conversationally-paced speech
Speaker-Independent Voice Recognition – understands speech from a voice it has never heard before

15. Other Input Technologies
II. Input technologies
Optical Scanning – converts text or graphics to digital input for direct entry of source documents
Other Input Technologies
Magnetic Stripe – on credit cards
Smart Cards – contain an embedded chip
Digital Cameras
Magnetic Ink Character Recognition (MICR) – used in banking industry

16. Forget the ATM: Deposit Checks Without Leaving Home
What does federal Check 21 Act allow?
What is the concern of consumers remotely depositing checks?
What basic security is provided?
What limits/restrictions are placed on the consumers?

17. IV. Storage Tradeoffs

18. Direct and Sequential Access
IV. Storage Tradeoffs
Direct and Sequential Access
Direct Access and Random Access are the same concept; locate an address on the storage device and go directly to that location for data access
Sequential Access – All tape devices are accessed serially – device must be read one record at a time from the data until the desired data is found

19. V. Semiconductor Memory
RAM (Random Access Memory) – volatile, may be read and over-written
ROM (Read Only Memory) – non-volatile, may be read but not over-written or erased; PROM and EPROM may be reprogrammed
Flash (Jump) Drives – solid-state memory

20. Computer Storage Fundamentals
IV. Storage Tradeoffs
Computer Storage Fundamentals
Binary Representation – Two-state, on/off, +/-, 0/1
Bit – Binary digit, 0/1
Byte – Grouping of bits (typically 8 bits/byte), represents a single character
ASCII – formalized code determining what byte values represent which character
Storage capacities – kilobytes (KB), megabytes (MB), gigabytes (GB), terabytes (TB)

21. VI. Magnetic Disks – Hard drives are the most common form of secondary storage
RAID (Redundant Arrays of Independent Disks) Storage – interconnected groups of hard drives - fast speeds and fault tolerant (redundant backups)

22. Representing characters in bytes

23. VII & VIII. Magnetic Tape & Optical Disks
Magnetic Tape – slow speeds, but inexpensive for large amounts of backups
Optical Disks – CD-ROM, CD-R, DVD-R (cannot be erased or re-written); CD-RW, DVD-RW (may be erased or re-written)

24. VII. Radio Frequency Identification (RFID)
RFID – for tagging and identifying mobile objects (store merchandise, postal objects, sometimes living organisms); provides information to a reader when requested
Passive – no power source, derives power from the reader signal
Active – self-powered, do not need to be close to the reader
RFID Privacy Issues – may be used as spychips; gathers sensitive information about an individual without consent