fundamentals of computer processing

Fundamentals

of

Computer Processing

Computer SizesComputer Sizes Mainframes -- the first Supercomputers -- the largest Minicomputers -- the first effort to achieve reduced

size Microcomputers -- made possible by microprocessor

PC -- used by one person, or by a few people in the same area

Workstations, lap tops, notebooks, and palmtops

The Computer SchematicThe Computer Schematic

Processor = Control unit + ALU

The computer is a closed-loop system

Control Unit

Arithmetic and Logic Unit

Primary Storage Unit

Central Processing Unit(CPU)

TheComputerSchematic

Input DataOutputInformation

SecondaryStorage

Unit

Computer HistoryComputer History Prior to 1950s

Keydriven machines– (some were called bookkeeping

machines)

Punched card machines

Computer History Computer History (continued)(continued)

1951 -- first commercial computer (a UNIVAC I) installed at the Census Burea

1954 -- first computer installed in a business (another UNIVAC I at GE)

Early 1970s -- minicomputers Late 1970s -- microcomputers (TRS-80,

Commodore PET) 1982 -- IBM PC

Primary StoragePrimary Storage

Evolution in storage media:

Magnetic drums

Magnetic cores

Integrated circuits (1964)

Bits and Bytes (KB, MB)Bits and Bytes (KB, MB)

RAM and ROM

Cache memory

One kilobyte (1KB) is 210 bytes (1,024)

One megabyte (1MB) is 220 bytes (1,048,576)

Input DevicesInput Devices

Keyboard

Ergonomic considerations (human engineering, human factor considerations)

QWERTY keyboard vs. Dvorak keyboard

Pointing DevicesPointing Devices

Mouse Trackball Touch screen Light pen Remote control device

Source Data Automation Source Data Automation (SDA)(SDA)

Input bottleneck Optical character recognition (OCR) is big

in retailing– Supermarket scanners– Point of sale (POS) terminals

Magnetic ink character recognition (MICR) was big for banks starting in the late 1950s

Technologies used for Technologies used for POS TerminalsPOS Terminals

Mark readers Barcode readers Character readers Handprint readers

Speech RecognitionSpeech Recognition

Speaker dependent

Speaker independent

Output DevicesOutput Devices Displayed

– CRT, VDT– Flat-panel

Printed– Speed– Quality

Speech (audio response unit)– digitized or playback

Microfilm

Computer

ABC123

Plotters

Speech OutputDevices

Printers

Displayed OutputDevices

Means ofProducin

g Compute

rOutput

PrintersPrinters

Impact Nonimpact

Line Character

Dotmatrix

Daisywheel

Page LaserInkjet

Output Devices Output Devices (continued)(continued)

Plotters– Flatbed– Drum

Microform– Microfilm (roll)– Microfiche (sheet)

Tabular versus graphical versus narrative

SoftwareSoftware Input and output devices communicate

directly with the manager and are considered to have a direct role

Source data automation devices play an indirect role

Two main types of software -- system and application

System SoftwareSystem Software

Three main types:

– operating system– translators– utilities

Operating SystemOperating System Basic functions

– Schedule jobs– Manage hardware and software

resources– Maintain system security– Provide for multiprogramming– Handle interrupts– Maintain usage records

Language TranslatorsLanguage TranslatorsSoftware GenerationsSoftware Generations

– First -- machine language– Second -- assemblers– Third -- compilers and interpreters

»Procedure-oriented language»Problem-oriented language

– Fourth -- natural language (4GL)– Nonprocedural – Types of 4GLs (example: FOCUS)

Source

Program

Translate

ObjectProgram

OutputInputData

The Program is Translated Before the Data is Processed

1

2

MuchMuch

DSSDSSpowepowe

rr

LittleFriendlyFriendly UnfriendlyUnfriendly

User User friendlinessfriendliness

Database Database Query Query

LanguageLanguage

Modeling languagesModeling languages Very Very

high-level high-level languageslanguages

ReportReportwriterswriters

ApplicationApplication generatorsgenerators

Fourth-generation Languages Offer Unique Combinations of Fourth-generation Languages Offer Unique Combinations of Power and User FriendlinessPower and User Friendliness

GraphGraphgeneratorsgenerators

FOCUS Instructions to Prepare a Report

DEFINE FILE SALESREGION/A12=DECODE REGION(NE ‘NORTH EAST’

SE ‘SOUTH EAST’ MW ‘MID WEST’MA ‘MID-ATLANTIC’);

ENDTABLE FILE SALESHEADING CENTER“PRODUCT UNIT SALES ANALYSIS </1”SUM UNITS AND ROW-TOTAL AND COLUMN-TOTAL ACROSS REGION BY PRODNUM AS ‘PRODUCT NUMBER’END

Application SoftwareApplication Software Custom programming versus prewritten

packages Four categories of prewritten packages

1. General business2. Industry-specific3. Organizational productivity

GDSS, E-mail, project management, forecasting, stat packages

Application Software Application Software (continued)(continued)

4. Personal productivity (or application development software)»Word processing»Spreadsheets»Graphics»desktop publishing, etc.

Direct versus indirect roles of software

Application SoftwareApplication Software

C B I SSoftwareType

General BusinessIndustry-specificOrganizationalproductivity

DP MIS OA ESDSS

Personalproductivity

User FriendlinessUser Friendliness Guided dialog

– Menus– Form-filling

Context sensitive help– Help screen or help messages

Graphic user interface (GUI)– Icons, buttons, toolbars, and others

Error ControlError Control Error prevention

– Protected format Error detection

– Edit routines Error correction

– Edit commands

MultimediaMultimedia Combines different forms of computer

output, allows richer communication Began in late 1980s Multimedia in business

– accounting information systems (documedia)– MIS and DSS via graphs, three-dimensional

graphics and animation– office automation; workgroup computing,

desktop video– knowledge-based systems

The Multimedia System Development ProcessThe Multimedia System Development Process

Communications Communications ProfessionalsProfessionals

Information SpecialistsInformation Specialists UserUser

Define the problem

Design the concept

Design the content

Write the script

Design the graphics

Produce the system

Conduct user tests

Use the system

Maintain the system

Step 1

Step 2

Step 3

Step 4

Step 5

Step 6

Step 7

Step 8Step 9