GENERAL OVERVIEW OF COMPUTER TECHNOLOGY

(The following notes are intended for use as a study guide for Mr.Burns CISM2201 course. Please report any syntax or semantics errors to me.) Click on the following links for my presentation screens for overview, hardware, and software lectures.

INFORMATION TECHNOLOGY OVERVIEW

COMPUTER CAREERS – Computer science majors have the highest average salaries over all other majors in a bachelor’s degree. Some common positions in the computer field include:

· Programmer – Creates the software via coding in a computer language.

· System Analyst - Analyzes the overall design of an information system and assigns segments to each programmer.

· Web Master or Designer – Designs and maintains web materials for business.

· Networking Specialist – Sets up and maintains computer networks.

· Database Specialist – Sets up and maintains the information databases.

· Game Designer

· Computer Consultant

COMPUTER ISSUES

· Computer Literacy

· Information Privacy (identity theft)

· Information Accuracy

· Hackers and Crackers

· Viruses and Worms, Trojan Horses and logic time bombs

· Software Piracy

· Computer security: firewalls and Encryption

Three ways that you can protect yourself from problems involving hackers and viruses are:

· Do not open email attachments unless your certain that they don’t carry a virus

· Always be sure that your operating system has all the up-to-date patches

· Always use encryption for any sensitive data such as giving out credit card #s over Internet

AGRARIAN SOCIETY -> INDUSTRIAL SOCIETY -> INFORMATION SOCIETY

In the 20^th century, our society transformed from rural farm based communities to industrialized cities. In the 21^st century, our society is evolving into a virtual information society. We are at the beginning of a new era where all knowledge is linked together in a vast electronic Cyberspace. Computer technology is the basic catalyst tool to create this information revolution.

A COMPUTER IS AN ELECTRONIC TOOL USED TO PROCESS INFORMATION (move data, calculate, logic comparisons) BASED ON A SET OF INSTRUCTIONS.

TWO COMPONENTS IN EVERY COMPUTER

1. HARDWARE (ELECTRONIC TOOL) The hardware consists of all of the physical components, including chips, wires, disk drives, and peripheral equipment such as printers and monitors.

CPU (Central Processing Unit)

SECONDARY STORAGE

INPUT DEVICES

OUTPUT DEVICES

2. SOFTWARE (INSTRUCTIONS) Software is the set of programs that tell the computer what to do.

OPERATING SYSTEMS

APPLICATION SOFTWARE

PROGRAMMING LANGUAGES

All electronic devices have either the presence or the absence of an electronic pulse. Because of this, all instructions and data in a computer are stored in the binary system. The binary system is based on 2 digits rather than the base 10 decimal system that we are all familiar. All text and numbers are represented in binary so that each character is encoded as a byte. A byte is 8 bits or on/off states (1=on 0=off).

Computer storage is measured in bytes (characters of information) so that a:

               KILOBYTE = THOUSAND BYTES

               MEGABYTE = MILLION BYTES

               GIGABYTE = BILLION BYTES

               TERABYTE = TRILLION BYTES

THE BINARY NUMBER SYSTEM   128   64   32   16    8    4    2    1

FOR LETTERS AND SPECIAL CHARACTERS (ex. *,%) A CODE IS USED. Unfortunately every software manufacturer uses different codes. Some standard codes are ASCII for micros, EBCDIC for mainframes.

CLASSIFYING DIGITAL COMPUTERS

-MICROCOMPUTERS- Includes P.C.s and laptops, Desktops, and workstations

-MINICOMPUTERS- Medium size database applications shared by less than 50 users typically.

-MAINFRAMES- Large computer system that is typically a database application shared by many users, usually over 50. Operating system uses a complex technique called time sharing to allow hundreds of programs to run simultaneously.

-SUPERCOMPUTERS- Usually research computers for number crunching scientific algorithms (Cray cooled by artificial human blood). IBM Connection machine defeats Chess Champion Karnov. It uses parallel processing and artificial intelligence modeling. Very expensive and not used for typical business processing.

FACTORS INVOLVED IN CLASSIFYING COMPUTERS:

-CPU SPEED (BIPS billion Instructions per second), -COST, -ARCHITECTURE, -NUMBER OF USERS

DISTRIBUTED DATA PROCESSING

BUSINESSES ARE TENDING TO BREAK DOWN LARGE COMPUTER SYSTEMS INTO SMALLER COMPUTER SYSTEMS AND CONNECT THEM VIA NETWORKS. Firms such as Georgia Pacific are phasing out their old monster mainframes with sleek networks of micros. THERE IS A BIG DIFFERENCE BETWEEN DUMB TERMINALS CONNECTED TO A MAINFRAME AND A NETWORK OF MICROCOMPUTERS. Networking is connecting a group of computers together via phone cable while in the past, many corporations had slews of terminals all connected to one huge main computer mainframe. Networking is more cost effective as well as a better connectivity tool rather than one large central computer controlling an entire company database of information.

***********SLIDE PRESENTATION ON HISTORY OF COMPUTERS ***********

- FIRST GENERATION (40’s) - Vacuum tubes for storage, programming is done by flipping switches.

- SECOND GENERATION (50's) - Transistors and magnetic core run cooler, smaller, faster. Grace Hopper creates the first programming language - Assembler.

- THIRD GENERATION (60's) - Integrated Circuits and Silicon Chips and a host of new computer languages.

- FOURTH GENERATION (70's & 80s) - VLSI silicon chips (Very Large Scale Integration) and the first microprocessors - all circuitry of a CPU on one chip.

- FIFTH GENERATION (turn of the century to recent times) parallel processing on neural networks, artificial intelligence software design, but most importantly Networking!!!!!!

HARDWARE

                      4 COMPONENTS OF THE CONCEPTUAL COMPUTER

                   INPUT   à CENTRAL PROCESSING UNIT   à  OUTPUT

                                          SECONDARY STORAGE

1. CPU

The core of a computer is the Central Processing Unit or CPU. In today's microcomputers, one chip called a microprocessor controls the overall operation of the computer. Typically, CPU chips are classified by the speed of calculations in megahertz or gigahertz (MHz or GHz). One MHz equals 1,000,000 cycles per second while a gigahertz represents one billion cycles. (Millisecond = one millionth of a second, Nanosecond = one billionth of a second). The original IBM PC operated at 4.77 MHz, whereas today chip manufacturers are all running over 2 GHz.

Although digital computers have many applications, basically, the CPU can execute only THREE BASIC TASKS: 1.perform arithmetic, 2.test relationships, 3.and move data around.

But it can do these operations billions of times in one second (BIPS).

A CPU is the single most important descriptor of a computer. For example, if I were to ask what type of computer you have, your response might be a Pentium II running at 366 megahertz.

Different IBM compatible microprocessor chips from beginning to now:

INTEL: 8086, 80286, 80386, 80486, Pentium or P5, Pentium II , Pentium III, Pentium IV, Dual and Quad Processor

   The only competitor with Intel is AMD:    AMD K-6, K6-2, AMD ATHLON , AMD ATHLON XP, AMD Phenom Dual and Quad

Each microprocessor runs at a different clock speed such as a Pentium I runs between 60 and 166 megahertz (1 million clock cycles per second). Pentium III started at 450 MHz and up while the latest Pentium IV is now above 2 GHz.

Another way to measure the speed of a computer is by MIPS or BIPS. This is probably the most accurate way except that some CPU's are RISC (Reduced Instruction Set Computer) chips and others are CISC (Complex Instruction Set Computer) chips.

3 PARTS OF CPU

  1. ARITHMETIC LOGIC UNIT - Mathematical and Logical functions

                             add, subtract and comparisons

  2. CONTROL UNIT - Interprets instructions, directs events

     uses system clock for timing, system bus for communications.

                                    data, control, address

  3. INTERNAL(PRIMARY MEMORY)

     Made up of RAM and ROM BIOS.  ROM is permanent memory while RAM is lost every time power is shut off.

Although computer technology has advanced at an incredible pace, the basic architecture of the original machines have not changed much. All computers still process information in the same basic pattern. The CPU FETCHES, DECODES, EXECUTES, AND STORES RESULTS.

STEP 1: The CPU fetches an instruction from internal memory.

STEP 2: The Arithmetic Unit decodes the instruction.

STEP 3: The Arithmetic Unit executes the command.

STEP 4: The result is stored back in RAM memory.

Typical ATX Motherboard

The Motherboard is the primary circuit board inside the computer that connects most all of the components. The CPU chip is mounted on a ZIF socket on the motherboard. Also included on the motherboard is the Bios (Basic Input Output System) chip, sockets for RAM internal memory, ATA / EIDE sockets for the floppy and hard drive cables, and expansion slots for the add-in cards. Common add-in cards are video cards, sound cards, SCSI cards, and network / modem cards. Types of expansion slots for these add-in cards include AGP,PCI, and ISA. These expansion slots are very important as they facilitate most additional equipment. PCI and AGP are superior to ISA for connection speed.

Motherboards use different types of electronic chips, know as chipsets such as Intel brand. They also use two different CPU processor types. Intel makes the Pentium brand CPUs. The other CPU type is the "Socket 7", made by Intel and AMD.

Motherboards come in many configurations. Depending on the type of BIOS and the chipset used, the speed of data transfer, and corresponding speed of the CPU chip can be varied. Increasing CPU speeds dictate newer chipsets, and new motherboard configurations. For example. a motherboard purchased six months ago, may well not be able to support the newest CPU chip because of the speed. CPU and motherboard speed is noted in megahertz or MHz. A megahertz is a million hertz or one million clock cycles per second. The clock of the computer is a circuit that generated out a series of evenly spaced pulses. Switching activity occurs when the computer is sending out a pulse. Thus a 500 MHz computer is generating 500,000,000 pulses per second.

Random Assess Memory (RAM) are the memory chips that fit into SIMM sockets on the motherboard. Along with the increasing speed of the CPU chips, the memory chips are also increasing in speed. The number of "pins" on each of the RAM chips increases with the speed of the chip. Chips have increased from 30 pin to the current 168 pin. Speed in the 168 pin RAM has increased from 100 MHz to 133 MHz in approximately 6 months. New chips in the 256 MHz are on the horizon.

Most motherboards come with a manual, which describes the operating parameters and CMOS/BIOS setup. This manual and any software drivers need to be kept with the computer.

Typically, two fans located inside the computer, keep the computer cool. One fan is located on the CPU. A second fan is located inside the power supply. If either of these fans fail, problems develop with the motherboard or power supply because of heat buildup. The power supply provides the electrical power to your PC. It actually is a transformer because it converts 120 volts AC to 12.5 volts DC.

Outside the computer are the monitor, keyboard, and mouse, which plug directly into the motherboard ports. Printers and scanners usually plug into USB (Universal Serial Bus) ports. They are popular now because they offer plug-and-play compatibility by recognizing any USB device as soon as its plugged in.

Buffer or Cache - is a temporary storage area between a fast and a slow device. It speeds up access between the CPU and other external devices.

GENERAL MISNOMER CONCERNING CPU SPEED

The CPU speed is just one factor but there are many other factors that make up the general operating speed of your computer. For example, a 500 MHz Pentium III CPU would be hampered if it had only 16 megabytes (MB) of RAM to operate with. In that case, a 350 MHz Pentium II CPU with 128 MB of RAM would be much faster within most applications on the market today. Also the speed of the overall computer system depends on other things such as the access speed of the hard drive and/or CD-ROM drive. When online slowdowns occur such as slow Internet access, it has nothing to do with your computer and everything to do with your connection device. Consider DSL or Cable telephone connection rather than the standard phone lines. As mentioned above, buffers and cache do speed up processing as well. This is why some chips such as the Intel Celeron are slower than the Pentium and AMD comparative chips. Also the system bus width is very important. Your bus is a highway of 64 to 128 parallel wires, which connect devices on the motherboard. A Pentium 60 MHz has a 32 bit bus (32 parallel wires) while a 100 megahertz 486 has only a 16 bit bus, therefore the Pentium is about the same process speed even though it runs at a slower megahertz. HARDWARE HAS OUT PACED SOFTWARE SO DON’T BUY THE PREMIERE HARDWARE SYSTEM UNLESS YOU HAVE MORE MONEY THAN BRAINS.

2. INPUT DEVICES

KEYBOARD most common

PUNCH CARD READER

MOUSE and JOYSTICK

MICR (Magnetic Ink Char. Readers) used for bank checks, & MAGNETIC STRIPS on credit cards

Optical Recognition such as BAR CODE or OCR (Optical Character Readers)

TOUCH SCREEN

LIGHT PENS

IMAGE SCANNERS

SPEECH RECOGNITION – I think it will be popular in the near future

VIDEO CAPTURE

3. OUTPUT DEVICES

  1. MONITOR

Made up of Pixels(dots of light) which determine resolution along with dot pitch(distance between pixels .28 standard) . LCD monitors are one of the reasons that laptops are more expensive than typical desktop machines.

  2. PRINTERS

       CHAIN or BAND, or called LINE PRINTERS - super fast printers!

       DOT MATRIX  (not letter quality, slow, inexpensive, and almost extinct)

       INK JET *-probably best value

       THERMAL

       LASER (professional quality desktop publishing)

  3. PLOTTERS

  4. SOUND OUTPUT Sound cards connect to speakers.

  5. VIDEO OUTPUT  Create video tapes

  6. VIRTUAL REALITY HEAD SETS  The monitor of the future

4. SECONDARY STORAGE DEVICES

(non-volatile memory outside the CPU)

1. MAGNETIC TAPE (Sequential Access) cassette and reel to reel, Stored on 8 tracks. 800 bpi (bytes per inch) to 6250 bpi. Used only for backing up data on the hard drive in case of emergency.

2. DISK DRIVES Floppy diskettes are old technology. FIXED HARD DRIVES ARE SEALED AND HAVE TREMENDOUS STORAGE CAPACITY (80 Gigabytes are common for micros) AND ALSO ARE FASTER ACCESS THAN DISKETTES. Hard drives have steadily increased in storage capacity over the last ten years. Head Crashes are a major problem with hard drives so it is wise to back-up all data on another medium because they are one of the most delicate components of your computer..

3. OPTICAL STORAGE - involves lasers, most are read only, and slower than hard drives in most cases. Most software now comes on CD-ROM and you usually install parts or all of it on your hard drive before you can use it. Optical storage has the highest potential capacity for secondary storage mediums.

TYPES OF OPTICAL STORAGE

CD-ROM compact disk read only memory (most common)

CD-R (Recordable) - write once read many

CD-RW Recordable rewritable media.

4.USB FLASH MEMORY STICKS The newest secondary storage device has taken over for diskettes.

SOFTWARE

Software includes all information stored in your computer including your data and programs/instructions. Software is stored in files, which have to be stored on permanent storage devices such as diskettes (referred to as A: or B:), hard drives (C:), Optical disks, or zip disks.

Some drives such as your hard disk drive (C:) has the potential to store millions of files. Therefore you need to partition or categorize these files into folders (some times called subdirectories). The root directory is the base folder area where you are not in any folders or subdirectories.

THREE MAIN TYPES OF SOFTWARE

            -   Operating Systems

            -   Application software

            -   Programming Languages

1.)OPERATING SYSTEMS manage and control hardware and provide utility services to software, programmers and users.

Mainframe O.S.s are much more complicated because they have to juggle multiple users and programs at the same time

 (this is called timesharing).

Popular operating systems for microcomputers are:

DOS

UNIX - allows Multitasking and timesharing.

WINDOWS  - most common P.C. O.S.; many versions such as 3.1, 95, 98, NT, 2000, and XP.

2.)PROGRAMMING LANGUAGES - a batch of commands which are compiled

into machine language in order to create application software.

Different Generations of programming language

  1st generation - machine code

  2nd generation - Assembler uses a compiler

  3rd generation -

             COBOL and RPG    - business

             BASIC AND PASCAL - micros

             C and Fortran    - scientific

  4^th, 5^th generation - CASE Computer Aided Software Engineering

3.)APPLICATION SOFTWARE

  MAJOR TYPES OF APPLICATION SOFTWARE for P.C.'s

      1.WORD PROCESSING and desktop publishing

        Thesaurus, grammar checks, mail merge, etc.

      2.DATA BASE MANAGERS- an electronic filing cabinet

                    Simple file manager vs. DBMS

                    dbase ,paradox are examples

      3.SPREADSHEETS- is an electronic worksheet

                    Quattro, Excel, lotus are examples

      4.GRAPHICS    CAD software used by engineers to create precise specifications and blueprints.

                    Paint/draw software – A great tool for artistic work of graphics

                    Presentation software

                    Games

                    Educational software

      5.TELECOMMUNICATION / NETWORKING SOFTWARE

        Described below

TELECOMMUNICATIONS

A NETWORK is two or more computers linked by telephone lines.

Computers can communicate with remote users, other computers and

computer devisés (secondary storage, etc.).

Why network?

    1. Cost effective sharing of resources and data.

A minicomputer with 40 dumb terminals might cost over double what a

network with 40 micros would cost.

    2. Enhanced communication increases productivity.

ex.(client/server)(laptop salesman connect to server)

ex.(real estate office connects to headquarters)

ex.(direct data links between companies and suppliers)

4 MAIN CHANNELS OF COMMUNICATION

Microwave relays, Coaxial cable, Twisted pair, Fiber optics

MAKING THE CONNECTION IN A NETWORK

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MODEM - modulator demodulator converts digital form to analog audio

signals (two sound frequencies to represent ones and zeros).

Baud rate is very important when purchasing a modem

Used to be 300 BPS (bytes per second), now 33.6k and up are standard.

An internal modem means it will connect to an expansion board while

an external modem is a separate unit outside the CPU case.

TWO TYPES OF NETWORKS

1.)LOCAL AREA NETWORKS (LANs) - Computers linked within one local

area (not long distance).  All telephone cable is installed by

whoever sets up the network; none of the cabling is leased from AT&T

or any other telephone company.  Can be very simple such as sharing a

printer or very sophisticated connecting hundreds of different

computers, platforms and peripherals.

Peer-to-Peer Networks are really simple ones in which several P.C.'s

are connected with a single cable and can directly connect with one

another.  Most networks are more complex and have a server or host

computer which controls the network.

MAKEUP OF TYPICAL LAN:

·         FILE SERVER,

·         COAXIAL CABLE,

·         OPERATING SYSTEM FOR NETWORKING,

·         NETWORK INTERFACE CARDS.

·         EQUIPMENT SUCH AS MULTIPLEXOR, CONCENTRATOR, HUB, ROUTER, GATEWAY, BRIDGE.

2.)WIDE AREA NETWORKING - Is a long distance network which spans an

area too great to wire in-house.  The Internet is an example.

The potential for WANS in businesses is just being tapped. Improved

productivity in internal business applications as well as external

applications are constantly being found due to instant communication

between computers over long distances.

INFORMATION SUPERHIGHWAY ON THE INTERNET - The Internet is the largest network in the world. It has over a hundred million users in virtually every country in the world. It is the 1^st and only mass telecommunication path leading to the 5^th generation of computing where we will eventually reside in cyberspace.

EXPLORER IS THE MOST POPULAR COMMUNICATION PROGRAM TO ACCESS OR BROWSE THE INTERNET. It uses hypertext to access information as well as URL addresses. Search engines on the web are the best way to find a particular address if the URL is unknown. Meta search engines such as IXQUICK.COM allow you to traverse several search engines at one time.

Intranet is using the Internet interface in order for telecommunication within a business.

A meta search engine is a search engine that searches several search engines. An example is www.IXQUICK.com

Software Terms:

Patches: small pieces of software code created to fix problems found in a larger software package.

Updates: New versions of software incorporating bug fixes or patches, but not typically new features or enhancements.

Upgrades: New versions of software incorporating new features or enhancements.