imd 203 - ch01
TRANSCRIPT
Week 1Week 1Introduction to PC:Introduction to PC:PC HistoryPC HistoryHow Computer WorkHow Computer WorkComponenents of a PCComponenents of a PCa.a.Output DeviceOutput Deviceb.b.Input DeviceInput Device
IMD203 : IT Maintenance & Support Service 1
ObjectivesObjectivesLearn that a computer requires both
hardware and software to workLearn about the many different
hardware components inside of and connected to a computer
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Where did HCI innovations and philosophy come from?Who were the major personalities?What were the important systems?How did ideas move from the laboratory to the market?
Input/output devicesInput/output devicesInputInput OutputOutput
Early days connecting wires lights on displaypaper tape & punch cards paperkeyboard teletype
Today keyboard scrolling glass teletype + cursor keys character terminal + mouse bit-mapped screen + microphone audio
Soon? data gloves + suits head-mounted displayscomputer jewelry ubiquitous computingnatural language autonomous agentscameras multimedia
The lesson keyboards & terminals are just artifacts of today’s technologies new input/output devices will change the way we interact with
computers
From Image Shack web site //www.imageshack.us ; original source unknown
Eniac (1943)A general view of the ENIAC, the world's first all
electronic numerical integrator and computer.
From IBM Archives.
Mark I (1944)The Mark I paper tape readers.
From Harvard University Cruft Photo Laboratory.
IBM SSEC (1948)IBM SSEC (1948)
From IBM Archives.
Stretch (1961)Stretch (1961)A close-up of the Stretch technical control panel.
From IBM Archives.
Intellectual foundations
Vannevar Bush (1945) “As we may think” article in Atlantic Monthly
Identified the information storage and retrieval problem:new knowledge does not reach the people who could benefit from it
“publication has been extended far beyond our present ability to make real use of the record”
Bush’s MemexBush’s MemexConceiving Hypertext and the World Wide Web
a device where individuals stores all personal books, records, communications etc
items retrieved rapidly through indexing, keywords, cross references,...
can annotate text with margin notes, comments...can construct and save a trail (chain of links) through the
materialacts as an external memory!
Bush’s Memex based on microfilm records!but not implementedmmmm
mmmmmmm mmmmmm mmm
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J.C.R. Licklider (1960)
Outlined “man-computer symbiosis”
“The hope is that, in not too many years, human brains and computing machines will be coupled together very tightly and that the resulting partnership will think as no human brain has ever thought and process data in a way not approached by the information-handling machines we know today.”
J.C.R. Licklider (continued)Produced goals that are pre-requisite to “man-computer symbiosis”
Immediate goals:time sharing of computers among many userselectronic i/o for the display and communication
of symbolic and pictorial informationinteractive real time system for information
processing and programminglarge scale information storage and retrieval
J.C.R. Licklider (continued)
intermediate goals: facilitation of human cooperation in the design & programming
of large systems combined speech recognition, hand-printed character
recognition & light-pen editing
long term visions: natural language understanding (syntax, semantics,
pragmatics) speech recognition of arbitrary computer users heuristic programming
Significant Advances 1960 - 1980Mid ‘60s
computers too expensive for a single person
Time-sharing the illusion that each user was on their own personal machine led to immediate need to support human-computer interaction
dramatically increased accessibility of machinesafforded interactive systems and languages vs batch “jobs”community as a whole communicated through computers
(and eventually through networks) via email, shared files, etc.
Ivan Sutherland’s SketchPad-1963 PhD
Sophisticated drawing package introduced many ideas/concepts now found in today’s interfaces
hierarchical structures defined pictures and sub-pictures object-oriented programming: master picture with
instances constraints: specify details which the system maintains
through changes icons: small pictures that represented more complex items copying: both pictures and constraints input techniques: efficient use of
light pen world coordinates: separation of
screen from drawing coordinates recursive operations: applied to
children of hierarchical objects
From http://accad.osu.edu/~waynec/history/images/ivan-sutherland.jpg
Ivan Sutherland’s SketchPad-1963 PhDParallel developments in hardware:“low-cost” graphics terminalsinput devices such as data tablets (1964)display processors capable of real-time
manipulation of images (1968)
Douglas EngelbartThe Problem (early ‘50s)
“...The world is getting more complex, and problems are getting more urgent. These must be dealt with collectively. However, human abilities to deal collectively with complex / urgent problems are not increasing as fast as these problems.
If you could do something to improve human capability to deal with these problems, then you'd really contribute something basic.”...Doug Engelbart
Douglas EngelbartThe Vision (Early 50’s)
…I had the image of sitting at a big CRT screen with all kinds of symbols, new and different symbols, not restricted to our old ones. The computer could be manipulated, and you could be operating all kinds of things to drive the computer
... I also had a clear picture that one's colleagues could be sitting in other rooms with similar work stations, tied to the same computer complex, and could be sharing and working and collaborating very closely. And also the assumption that there'd be a lot of new skills, new ways of thinking that would evolve “ ...Doug Engelbart
Douglas EngelbartA Conceptual Framework for Augmenting Human Intellect (SRI Report, 1962)
"By augmenting man's intellect we mean increasing the capability of a man to approach a complex problem situation, gain comprehension to suit his particular needs, and to derive solutions to problems.
One objective is to develop new techniques, procedures, and systems that will better adapt people's basic information-handling capabilities to the needs, problems, and progress of society." ...Doug Engelbart
Document ProcessingDocument Processing– modern word processingmodern word processing– outline processingoutline processing– hypermediahypermedia
Input / OutputInput / Output– the mouse and one-handed the mouse and one-handed
corded keyboardcorded keyboard– high resolution displayshigh resolution displays– multiple windowsmultiple windows– specially designed furniturespecially designed furniture
Shared workShared work– shared files and personal shared files and personal
annotationsannotations– electronic messagingelectronic messaging– shared displays with multiple shared displays with multiple
pointerspointers– audio/video conferencingaudio/video conferencing– ideas of an Internetideas of an Internet
User testing, trainingUser testing, training
The Personal Computer
Alan Kay (1969) Dynabook vision (and cardboard prototype) of a notebook
computer:
“Imagine having your own self-contained knowledge manipulator in a portable package the size and shape of an ordinary notebook. Suppose it had enough power to out-race your senses of sight and hearing, enough capacity to store for later retrieval thousands of page-equivalents of reference materials, poems, letters, recipes, records, drawings, animations, musical scores...”
Ted Nelson 1974: “Computer Lib/Dream Machines” popular book describing what computers can do for people
(instead of business!)
The Personal Computer
Xerox PARC, mid-’70s Alto computer, a personal workstation
local processor, bit-mapped display, mouse modern graphical interfaces
text and drawing editing, electronic mail windows, menus, scroll bars, mouse selection, etc
local area networks (Ethernet) for personal workstations could make use of shared resources
ALTAIR 8800 (1975) Popular electronics article that showed people
how to build a computer for under $400
Commercial machines: Xerox Star-1981First commercial personal computer designed for “business professionals”
First comprehensive GUI used many ideas developed at Xerox PARC
familiar user’s conceptual model (simulated desktop) promoted recognizing/pointing rather than remembering/typing property sheets to specify appearance/behavior of objects what you see is what you get (WYSIWYG) small set of generic commands that could be used throughout
the system high degree of consistency and simplicity modeless interaction limited amount of user tailor ability
Xerox Star (continued)First system based upon usability engineering
inspired design extensive paper prototyping and usage analysis usability testing with potential users iterative refinement of interface
Commercial failure cost ($15,000);
IBM had just announced a less expensive machine limited functionality
e.g., no spreadsheet closed architecture,
3rd party vendors could not add applications perceived as slow
but really fast! slavish adherence to direct manipulation
Commercial Machines: Apple Lisa (1983)based upon many ideas in the Star
predecessor of Macintosh, somewhat cheaper ($10,000) commercial failure as well
http://fp3.antelecom.net/gcifu/applemuseum/lisa2.html
Commercial Machines: Apple Macintosh (1984)“Old ideas” but well done! succeeded because:
aggressive pricing ($2500)did not need to trail blaze
learnt from mistakes of Lisa and corrected them; ideas now “mature”
market now ready for themdeveloper’s toolkit encouraged 3rd party non-Apple software interface guidelines encouraged consistency between
applicationsdomination in desktop publishing because of affordable laser
printer and excellent graphics
Commercial Machines: Apple
Apple Macintosh (1984) “old ideas” but well done!
succeeded because: aggressive pricing ($2500) did not need to trail blaze
learnt from mistakes of Lisa and corrected them; ideas now “mature”
market now ready for them developer’s toolkit encouraged 3rd party non-Apple software interface guidelines encouraged consistency between
applications domination in desktop publishing because of affordable laser
printer and excellent graphics
Other events:MIT Architecture Machine Group
Nicholas Negroponte (1969-1980+) many innovative inventions, including
wall sized displays use of video disks use of artificial intelligence in interfaces (idea of agents) speech recognition merged with pointing speech production multimedia hypertext ....
ACM SIGCHI (1982) special interest group on computer-human interaction conferences draw between 2000-3000 people
HCI Journals Int J Man Machine Studies (1969) many others since 1982
You know now:
HCI importance result of:
cheaper/available computers/workstations meant people more important than machines
excellent interface ideas modeled after human needs instead of system needs (user centered design)
evolution of ideas into products through several generations pioneer systems developed innovative designs, but often
commercially unviable settler systems incorporated (many years later) well-
researched designs
people no longer willing to accept products with poor interfaces
IntroductionEnd users need not know how a computer worksTo add to your end user knowledge, study is
needed Studying this text will help you do the following:
Install new hardware and software Diagnose hardware and software problemsSolve hardware and software problemsEvaluate new hardware and operating systemsPass the A+ series of exams
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Hardware Needs Software to WorkHardware: physical portion of a computer
Components: monitor, keyboard, memory, hard driveSoftware: instructions used to manipulate hardware
Requirements: input, processing, storage, output All hardware operations are based on binary valuesBinary number system consists of two digits: 0 and 1Fundamental groupings of binary numbers:
Bit: binary digit that can take on values of 0 or 1Nibble: four bitsByte: eight bits
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Figure 1-2 All communication, storage, and processing of data inside a computer are in binary form until presented as output to the user
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PC Hardware ComponentsMost input/output (I/O) devices are external to case Most processing and storage devices are internalCentral processing unit (CPU)
Also called the processor or microprocessorReads input, processes data, writes data to storage
Elements required by I/O and storage devicesA method for CPU to communicate with the deviceSoftware to instruct and control the deviceElectricity to power the device
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Hardware Used for Input and OutputConnections to the case can be cabled or wirelessPort: access point located in back or front of caseChief input devices:
Keyboard: enhanced type holds 104 keysMouse: pointing device used to select screen items
Chief output devices:Monitor: visually displays primary output of
computerPrinter: produces output on paper (hard copy)
A+ Guide to Managing and Maintaining your PC, 6e 36
A+ Guide to Managing and Maintaining your PC, 6e 37
Figure 1-6 The two most popular output devices are the monitor and the printer
Hardware Inside the Computer Case
Most storage and processing occurs in the caseInternal devices common to most computers:
Motherboard containing CPU, memory, other parts Floppy drive, hard drive, CD drive for persistent storagePower supply with power cords supplying electricityCircuit boards for internal and external communicationCables to connect devices to all circuit boards
Expansion cards are installed in expansion slotsTwo types of cables: data (communication) and power
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Figure 1-8 Inside the computer case
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The MotherboardThe largest and most important circuit board
Also known as the main board or system boardContains the CPU, expansion slots, other devices
Categories used to group motherboard components Processing, temporary storage, communication, power
All devices communicate with CPU on motherboard A peripheral device links to motherboard via cableSome motherboard ports outside of the case:
Keyboard, mouse, parallel, USB ports, sound ports
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A+ Guide to Managing and Maintaining your PC, 6e 41
Figure 1-9 All hardware components are either located on the motherboard or directly or indirectly connected to it because they must all communicate with the CPU
A+ Guide to Managing and Maintaining your PC, 6e 42
Figure 1-10 A motherboard provides ports for common I/O devices
The Processor and the ChipsetCPU: chip that performs most data
processingChipset: group of microchips controlling data
flowPersonal computer (PC): chief focus of this
textMajor manufacturers of CPUs and chipsets
for PCsIntel Corporation, AMD, VIA, SiS, and Cyrix
A+ Guide to Managing and Maintaining your PC, 6e 43
A+ Guide to Managing and Maintaining your PC, 6e 44
Figure 1-12 This motherboard uses two chips in its chipset (notice the bus lines coming from each chipused for communication)
Storage DevicesPrimary storage (main memory):
Temporary storage used by the processorExample: RAM (random access memory)
Secondary storage (permanent storage):Enables data to persist after the machine is turned
offExamples: hard drive, CD, floppy disk
Analogy to primary-secondary memory relationshipBook stacks in a library are like permanent storageBooks can be moved to a desk (temporary storage)
A+ Guide to Managing and Maintaining your PC, 6e 45
A+ Guide to Managing and Maintaining your PC, 6e 46
Figure 1-13 Memory is a temporary place to hold instructions and data while the CPU processes both
Primary Storage
RAM (random access memory):Device providing temporary storageLocated on motherboard and on other circuit
boardsThree types of RAM boards (memory modules):
DIMM (dual inline memory module)RIMM (Rambus inline memory module)SIMM (single inline memory module)
RAM is volatile (data does not persist)ROM (read-only memory) is nonvolatile
A+ Guide to Managing and Maintaining your PC, 6e 47
A+ Guide to Managing and Maintaining your PC, 6e 48
Figure 1-14 A SIMM, DIMM, or RIMM holds RAM and is mounted directly on a motherboard
Secondary StorageHard drive
Case containing disks that rotate at high speedsAn arm with a read/write head traverses the platter
Integrated Drive Electronics (IDE)Technology used internally by a hard drive
ATA (AT Attachment) standardSpecifies motherboard-hard drive interface Types: Serial ATA or parallel ATA (Enhanced IDE)
Parallel ATA accommodates up to four IDE devices
A+ Guide to Managing and Maintaining your PC, 6e 49
A+ Guide to Managing and Maintaining your PC, 6e 50
Figure 1-16 Hard drive with sealed cover removed
A+ Guide to Managing and Maintaining your PC, 6e 51
Figure 1-18 Two IDE devices connected to a motherboard using both IDE connections and two cables
Secondary Storage (continued)Serial ATA standard
Allows for more than four drives in a system Applies only to hard drives and not to other drives
Some IDE devices: hard drives, Zip drives, CD driveFloppy drive
3.5-inch disk holding 1.44 MB of dataFloppy drive connector is distinct from IDE connectors
CD-ROM (compact disc read-only memory) driveStandard equipment for reading software distributions
A+ Guide to Managing and Maintaining your PC, 6e 52
A+ Guide to Managing and Maintaining your PC, 6e 53
Figure 1-22 A motherboard usually provides a connection for a floppy drive cable
Motherboard Components Used For Communication Among Devices Traces: circuits or paths that move data and powerBus: system of pathways and transmission protocolsData bus
Lines in a bus that carry the dataBinary bits correspond to voltage values of on or offData path sizes: 8, 16, 32, 64, or 128 bits wide
Main bus on motherboard (system bus, memory bus) Communicates with CPU, memory, and chipset
Pulse of system clock carried by line on motherboard
A+ Guide to Managing and Maintaining your PC, 6e 54
A+ Guide to Managing and Maintaining your PC, 6e 55
Figure 1-26 A data bus has traces or lines that carry voltage interpreted by the CPU and other devices as bits
Motherboard Components Used For Communication Among Devices (continued) Devices work according to beats (or cycles)Clock speed is measured in hertz (cycles/second)
One megahertz (MHz): one million cycles per secondOne gigahertz (GHz): one billion cycles per second
Common ratings for motherboard buses1066 MHz, 800 MHz, 533 MHz, or 400 MHz
Range of CPU speeds: 166 MHz to 4 GHzBuses for expansion slots: PCI, AGP, ISA
A+ Guide to Managing and Maintaining your PC, 6e 56
A+ Guide to Managing and Maintaining your PC, 6e 57
Figure 1-29 PCI bus expansion slots are shorter than ISA slots and offset farther; the one AGP slot is set farther from the edge of the board
Interface (Expansion) CardsSome names for circuits mounted in expansion
slots:Circuit cards, adapter boards, expansion cards, cards
Cards that connect the CPU to an external device:
Video: provides a port for the monitorSound: provides ports for speakers and microphonesNetwork: provides a port for a network cableModem: provides ports for phone lines
Determine a card’s function by identifying its port
A+ Guide to Managing and Maintaining your PC, 6e 58
A+ Guide to Managing and Maintaining your PC, 6e 59
Figure 1-31 This circuit board is a modem card and is mounted in a PCI slot on the motherboard
The Electrical SystemPower supply
Most important electrical componentConverts AC voltage external source to DC voltage Reduces voltage from 110-120 volts to 12 volts or
lessRuns a fan to cool the inside of the computer case
Temperatures > 185° F can cause component failure
Motherboard has 1 or 2 connections to power supply
A+ Guide to Managing and Maintaining your PC, 6e 60
A+ Guide to Managing and Maintaining your PC, 6e 61
Figure 1-35 The motherboard receives its power from the power supply by way of one or more connections located near the edge of the board or near the processor
Instructions Stored on the Motherboard and Other BoardsBIOS (basic input/output system)
Data and instructions stored on ROM chipsROM BIOS chips are a type of firmware
Three purposes served by motherboard ROM BIOS:System BIOS: used to manage simple devicesStartup BIOS: used to start the computerCMOS setup: used to change motherboard settings
CMOS RAM: includes date, time, port configurations
Flash ROM: ROM chips the can be overwritten
A+ Guide to Managing and Maintaining your PC, 6e 62
A+ Guide to Managing and Maintaining your PC, 6e 63
Figure 1-36 This firmware chip contains flash ROM and CMOS RAM; CMOS RAM is powered by the coin battery located near the chip
Advanced Configuration and Power InterfaceAlso known as ACPI Standards specifying a power saving featureEnables a system to power up by a keyboard Supported by most systems, such as
Windows XPAdvanced Power Management (APM)
Older BIOS power management standard
A+ Guide to Managing and Maintaining your PC, 6e 64
Plug and PlayAlso known as PnPStandard simplifying installation of hardware
devicesPnP BIOS begins process of configuring devicesPnP-compliant operating system completes
configurationESCD (extended system configuration data)
Plug and Play BIOSEnhanced version of PnPStores manual configuration steps
A+ Guide to Managing and Maintaining your PC, 6e 65
Summary A computer comprises hardware and softwareMain functions: input, output, processing,
storageData is stored in a binary format (1 or 0, on or
off)Input/output devices: keyboard, mouse,
printer, monitorMotherboard (system board): contains the
CPU, access to other circuit boards and peripherals
A+ Guide to Managing and Maintaining your PC, 6e 66
Summary (continued)Primary storage (RAM) is volatile (temporary)Secondary storage is nonvolatile (permanent)Parallel and serial ATA standards: enable
secondary storage devices to interface with the motherboard
Computer bus: system of communication pathways and protocols
ROM BIOS helps start PCs, manage simple devices, and change some motherboard settings
A+ Guide to Managing and Maintaining your PC, 6e 67