IMD 203 - Ch01

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

2IMD203 : IT Maintenance & Support Service 1

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

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mmmm mmm

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


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


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


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


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


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



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


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



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)



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



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



Figure 1-16 Hard drive with sealed cover removed


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



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



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



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



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



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



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


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


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


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


IMD 203 - Ch01

Education

Transcript of IMD 203 - Ch01