Answers to Self-check Tests and to the Case Study

307

Self-check Test 1 1.D 2. A 3. C 4. C 5. input, output, input, input, input 6. on-line, not essential, on-line, not essential 7. D 8. C 9. C

10. digital, analog, analog, digital, digital 11. A 12. D 13. B 14. A 15. B 16. A 17. A 18. D 19. B

The following table shows marks for the test against approximate GCSE grade.

Your score GCSE grade Comment

25 plus 20-24 16-19 14-15 less than 14

B to A D to C F to E G

you are doing fine! not bad, check back! more revision please! only just! you better start again!

Self-check Test 2 Grade F Questions 1. Auto-pilot, robots. 2. (a) 3, 1,2,5.

(b) Search for all GCE and replace with GCSE. (c) Laser. (d) 1. PC can be used for other packages.

2. Dedicated word processor will be specifically designed for the job and will have special keys, etc.

3. (a) Better at repetitive tasks, e.g. mass production. (b) Better at boring tasks, e.g. monitoring control

systems. (c) Better at complex calculations.

4. (a) Optical character reader. (b) Bar code reader. (c) Optical mark reader.

5. (ii) Dedicated. (iii) Real-time. (iv) Batch. (v) Multi-access.

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6. (a) B. (b) PASCAL. (c) C. (d) SORTing.

7. (a) 3, 9. (b) 4. (c) 1,2,7.

Grade C Questions 1. (a) B.

(b) arithmetic operations. 2. (a) A.

(b) combining them. 3. Direct, serial, direct.

4. (a) VO. (b) One letter limits use to 26 car manufacturers. (c) Quicker to type. (d) (i) To identify the record.

(ii) Unique to the vehicle. (e) (i) Car sale.

(ii) New car for sale. (iii) Price change.

5. X Y Z F 0 0 1 1 0 0 1 1 0 0 0 0 0 1 0 1 0 0 1 1 0 0 1 1 1 0 0 1 1 1 0 1

6. Counter Sum OUTPUT 1 0 2 12 3 26 4 37 5 47 5,5

7. So that the customer file can be updated. Records in both files need to be in the same order (customer number), as one record from each is read in to be compared and processed in batch mode.

Grade A Questions 1. A.

2. (a) Multi-access, time-sharing. (b) Polls terminals on a round-robin, allowing each

user a 'burst' (time-slice) of CPU time.

3. (a) Telephone, modem, communications software. (b) A database package. (c) PC must have the appropriate language trans­

lator. (See Chapter 8, page 155, for further explanation.)

4. (a) 1. Print requests spooled to a print queue and printed out in turn.

2. Screen message to user to try later.

(b) Shared data; security and control problems potentially increase.

5. (a) 1 Easier to use. 2 Quicker to use. 3 Unique.

(b) CUSTOMER file: customer number, name, address, telephone number. VIDEO (stock) file: video number, title, customer number (loaned to), date of loan.

(c) (i) Hardware 'outside' the computer. (ii) Keyboard for data entry; monitor for dis­

play; [printer for receipts].

(d) 1. Customer mailing list for other activities. 2. Evidence of customer credit-worthiness,

tastes and video ownership.

6. (a) Package: ready-made applications software. Integrated software: an applications package linking several applications (often modules of the same program).

(b) Spreadsheet; database; graphics. (c) 1. Easy transfer of data from one application to

another, e.g. spreadsheet figures into a report in the word processor.

2. Similar command structure in all modules -no need to learn different packages.

Self-check Test 3 1. (a) (i) random access memory

(ii) approximately 640 000 bytes of memory (iii) (1) speed - dot-matrix are usually faster

(2) quality of print - daisy is letter quality (3) capability - a daisy-wheel cannot print graphics

(b) The third option. Pick the best software first and then look for a suitable hardware configuration.

(c) Just in case the data on the original disk is lost or corrupted.

(d) Parallel running means running the new com­puter system along with the old (usually manual) system. It is advisable to do this because (a) you have an alternative if something goes wrong with the computer and (b) you can compare results for accuracy and completeness.

(e) (1) a non-technical description of what the software should do

(2) instructions for installing, loading and runn­ing the software

(3) instructions for operating the software (4) explanations of error messages

(f) (1) a better control of the shop's accounts -they will know who has what and how much has been paid.

(2) better stock control - easier to identify popular videos etc.

2. (a) (i) (1) start up and close down computer (2) monitor status of programs running on the computer

(ii) (1) ensure that no data gets lost in the organisation

(2) collect printed output and send it to appropriate section

(b) system specification and program documenta­tion

(c) (i) electronically programmable read only memory

(ii) replace chip (d) (i) punctuation/grammatical errors

(ii) interpreter or compiler will flag them (iii) program editor

(e) Increased automation in the car plant - intro­duction of robots on the production line etc. will account for the drop in plant staff. The growth in computer staff is attributable to the upgrading and development of computing within the com­pany as more computer-based systems come on stream.

3. (i) Application packages are designed to do a speci­fic task, e.g. payroll, although many are more general purpose, e.g. spreadsheet Utilities are systems programs which help man­age the computer system, e.g. to copy or delete a file.

(ii) In a real-time system, data is input and processed quickly enough to affect/control the outcome. This instantaneous processing means that the results can influence any further input. If you book an airplane seat, that record is 'locked' ie and updated ie reserved so that no one else can book it.

Interactive processing is where user and com­puter are in two-way communication throughout the period of use, e.g. entering data while the program is running.

(iii) A line printer prints a line at a time, a laser printer prints a page at a time.

(iv) Data validation is checking data for reasonable­ness, accuracy and completeness. Data verifica­tion is keying the same data in a second time and checking any differences.

(v) Data privacy is the confidential nature of certain data. Data security is the protection of data against accidental or deliberate misuse - loss, modification or disclosure.

4. (a) File - a collection of records, e.g. personnel Record - a collection of fields describing a

person or an item.

5.

309

Field - a detail or attribute about a person or an item, e.g. sex, date of birth

(b) NHS number, name, address, phone number, previous medical history

(c) (i) Accessed serially one after the other in a predetermined order (i.e. sorted)

(ii) Direct access means going straight to the record without having to read others

(d) (i) Patient reference number (could use NHS number)

(ii) Direct; sequential would be much too slow (iii) Hard disk (iv) Database management package

(e) Personal computer with hard disk and quality printer for word processing and a modem link for communications

(f) (i) Using a communications package, vIa modem and telephone link

(a)

(ii) Files may be incompatible because computers have different operating systems; data may be structured in different ways as doctors have built up their own system.

Field Type Length Example

customer number numeric 4 1234

name alpha 25 Mr Judy Cassells

address alpha 30 7 Andover Road

Winchester 5022 4DF

phone alpha 12 0962-558823

room number numeric 4 2914

date start numeric 6 201092

date end numeric 6 221092

(b) See (a): 87 characters per record, say 100 (there will be other fields), gives 100 X 3600 plus customers =360000 bytes

(c) See (a) (d) Building number 5, floor 4.

Show 36 bedrooms on screen For each bedroom there should be displayed;

• booking status (occupied/empty); • type of room (single/twin etc.); • present guest(s} if applicable; • expected checkout date.

(e) Unless the room booking file is updated in real time from the customer file the hotel will not have up-to-the-minute information about room occupancy.

Case-study - Worked Example 1 (a) (i) Implementation; (ii) investigation; (iii) mon­

itoring; (iv) analysis; (v) design. (b) (i) A. Up-to-date-information;

Quick information from all 8 shops; Relevant information, e.g. houses within a certain price range.

310

B. Details can be sent to prospective buyers much more quickly, thereby improving the chances of a sale.

C. Immediate, up-to-date information, im­proving the efficiency and effectiveness of the business.

(ii) Direct, immediate access necessary. (iii) Quiet. (iv) The digitiser can be used to scan house photo­

graphs into the computer. (v) A. To take details away for further study.

B. Page (laser) printer. Quality print; ability to print a mix of text and graphics; quiet (non-impact).

(vi) A. Database management software. B. No need to sort files, e.g. by price.

2. (a) (i) File; (ii) record; (iii) field. (b) Reference number, unique so that the relevant

record can be located on file. (c) Ensures that the search will extract property by

type effectively. (d) (i) Confidentiality; (ii) avoids possible bias and

need only release sellers' names with their per­mission.

(e) Reference number 6, N; address 25, A; property 2, A; bedrooms 1, N; date 6, N.

(f) Avoids wasted visits to houses. 3. (a) Searched

(b) (i) Reference numbers: 359413, 459656, 492144, 555921, 594356.

(ii) You get information that you ask for, not the complete list.

(c) Password protection. 4. (a) date; don't want to send repeat details.

(b) FAIL; PASS; FAIL; FAIL. (c) (i) Commercial advantage; contravenes Data

Protection Act. (ii) If you do not want your name and address passed on to other people, tick the box 0

(d) See document below.

PERSONAL DETAILS: Ref no. xxxx

TITLE: MRiMRSlMS FIRST NAME .... 1 ___ ....J SURNAME ,-I ___ ....J

ADDRESS: ____________ _

POSTCODE .... 1 ___ ....J

DETAILS OF PROPERTY SOUGHT:

UPPER PRICE LIMIT

NO. OF BEDROOMS

TYPE OF PROPERTY REQUIRED, e.g. FLAT ________ _

OTHER REQUIREMENTS

DATE xx:xx:xx

(e) All interested buyers are contacted. 5. See flowchart below.

(b) (i) Details on a VDU, compared with agent's original written details.

(ii) Reference number; to cross-reference with PROPERTY file.

(c) (i) Magnetic tape (flowchart symbol). (ii) Paper - print out.

(iii) Parent-child principle (file generations). (d) INPUT; VERIFY; SORT; UPDATE.

Index Absolute address 32, 165 Access code 283 Access time 39 Accounting software 161 Accumulator 164 Activator 85,243 Addressing modes 165 Addressing records 103 Alarm systems 240 Analog 8 Analog-to-digital converters 8, 243 Analysts' workbenches 256 AND gates 24 Application generators 256, 265 Application software 154-62 Applications programmers 282 Applications programs 154 Archive storage 36 Argument 98, 202 Arithmetic and logic unit (ALU) 5 Arrays 203 Artificial intelligence (AI) 168 ASCII codes 22 Assemblers 152 Assembly language 166 Asynchronous transmission 126 Audit trail 109,278 Authoring languages 168

Background jobs 152 Backing store 4,35-44 Back-ups 38, 104, 108 Badge readers 60 Ball printer 78 Banking (example) 240 Bar codes 59-60 BASIC 10, 167, 198-204 Batch processing 105, 126, 151,275 Baud rate 127 Binary arithmetic 19-20 Binary fractions 19 Binary numbers 18 Binary-to-decimal conversion 18 Bistable 23 Bit 17 Block coding 55 Blocks 36 Booting up 41, 150 Branches 200 Broadband 127 Bubble memories 44 Bubble sort 107 Buffer 34 Buffering 152 Bugs 189 Bureaux 279-80 Buses 164 Byte 17,36

Call-connect system 128 Capacitors 35

Cassette tape 38 CD-ROM 42, 44 CEEFAX 136 Central Processing Unit (CPU) 5, 35

169 Change-over methods 265-6 Character codes 22 Character printers 77 Check bit 22 Check digits 53-4 Clock 164 Clone 8 Closed subroutine 189 COBOL 167 Coding 54-5 Command flle 157 Command language 138 Commercial data processing 230-40 Communication processors 125 Communications 122-39 Communications controller 130 Communications software 124, 162 Compatibilty checks 53 Compilers 152, 190 Compile time 190 Computer aided design (CAD) 81,

160-1,241 Computer aided learning (CAL)

246-47 Computer aided manufacture (CAM)

245-6 Computer arithmetic 19-21 Computer based training (CBT) 282

see also CAL Computer bureaux 237-8 Computer control 243 Computer department 279 Computer managers 276 Computer operating staff 278 Computer output on microfllm (COM)

42 Computer programmers 277 Computers

advantages and disadvantages of 10 applications of 230-47 choosing 268 introduction to 2-15 and people 279-83 types of 6-8, 82-3

Concentrator 133 Conditional branch 200 Constant 198 Continuous motor 85 Continuous stationery 76 Control characters 22 Control program 243 Control and review 266 Control unit 5, 174 Conversational mode 81, 151 Conversational time sharing 124 Coursework and case studies 298 C (programming language) 167 CPU 5, 35, 169

Crime 284-5 Current instruction register 164 Cursors 52, 82, 175

Daisywheel printers 78 Database administrator (DBA) 101 Database management systems

(DBMS) 100-1, 155 Databases 99

advantages of 100 software for 100-1, 155

Data collection 50, 105 Data communications 122-39

advantages of 124 components of 124

Data control staff 278 Data description language (DOL) 101 Data encryption 132 Dataflow diagram 261 Data heirachy 97 Data input methods 50-62 Data logging 62, 240 Data manipulation language (DML)

101 Data preparation 278-9 Data privacy 283-4 Data processing, commercial 230-40 Data Protection Act 1984 284 Data security 284 Data transfer times 39,53-5, 105 Data validation 53-5, 105,235 Debugging 153, 184, 189 Decoders 26 Desk check 9, 190 Desk-top publishing (DTP) 161-2 Diagnostics 190 Dialogue design 51-2 Digital 8 Digital-to-analog converter 8, 243 Digitisers 61 Dimension 203 Direct access 36, 103 Direct addressing 165 Direct data capture 4, 51,234 Directory 102 Disk capacity 39 Disk drive 39 Diskettes 4, 38-44 Disk operating system, see DOS Disks 4, 38-44 Disk sector 38 Disk track 38 Distributed computer system 132 Distributed processing 124 Documentation (of program) 184,188 Document reader 3,56-60 DOS 153 Dot matrix printers 78 Drum plotters 81 Dry run 2, 10, 203 DTP, see Desk-top publishing

Dummy values 200 Dump 38,108

EBCDIC code 22 Edit 153 Electronic funds transfer (EFT) 240 Electronic mail (El'vI) 5, 136-8, 242 Electronic office (worked examples)

242-3 Elements 203 Employment, effects of computers on

281-3 End user support staff 277 Enquiry/response 122 EPROM 35, 127 Errors, of numbers 21 European article number (EAN) 59 Exchangeable disk packs 38-9 Execution error 190 Expert system 168 Exponent 21 Expression 198

Faceted codes 54 Fanfold paper 76 Fault-tolerant 6 FAX 136-7 Feasibility checking 53-4 Feasibility study 258 Feedback 8,152,245 Fetch-execute cycle 163-4 Fibre optics 126 Fields 97 File handling 204--5 File librarian 279 File recovery 102 Files 97,235

direct 124 generations of 108 processing of 102 security of 108-9 serial 102

types of 101 File security 108-9 File servers 130 File structure 104 Firmware 35, 150 Fixed-disk pack 39 Fixed point numbers 20 Flat-bed plotters 81 Flip-flop 26 Floating point numbers 20 Floppy disks 4, 40-2 Flowcharts 9, 186-8

program 186 symbols 187 system 187

Font 79 Footer label 37 Format

of disk 41 of statement 198

Forms designs 51-2

FOR-NEXT loop 200 FORTRAN 167 Fourth generation languages 256, 265 Friction feed 76 Front-ends 125 Full duplex 127 Function keys 83 Functions, programming 202

Games paddle 61 Gas bill, worked example 201-2 Gates, logic 24--5 Gateways 134, 136 Generations, of files 108 Gigabyte (Gb) 4 GIGO 2 Global variable 198 Graphics characters 22 Graphics packages 160 Graphics pads 61 Graphics workstation 83

Hacking 124 Half-duplex 127 Hand-held computers 82 Handover 266 Handshake 127 Hard copy 76 Hard disks 4,38-40 Hard-sectored disks 40 Hardware 3,55, 124 Hash total 105 Headcrash 39 Header label 37 Health and safety 282 Hexadecimal numbers 19 Hierarchical codes 54 High-Iecvellanguages 152, 166-8 History files 102 Hit rate 104 Host computer 81, 129 Housekeeping routines 153

Icon 83 Identifier 198 IF ... THEN 200 Immediate access store 34 Immediate addressing 165 Impact printers 77 Implementation 265-6 Implied addressing 165 Index addressing 165 Indirect addressing 165 Information systems 241-4 Information technology (IT) 4 Ink-jet printers 78 INPUT 199 Input devices 55-62 Input media 55-62 Input methods 50-62 Inputvalidation 53-5 Instruction format 164 Instruction set 162 Integrated circuits 23

Integrated project support environment 256

Integrated services digital network 128 Integrated software 154 Intelligent terminals 81 Interactive 81, 151 Interactive video 43 Inter-block gaps 36 Interfaces 3 International Standards Organization

124 Interpretative coding 55 Interpreters 152, 189 Interrupts 151 Inverse video 52 Inverters 24 IT, and society 280-6 IT departments 274--9 IT jobs 279 IT managers 276

Job control 151 Joysticks 61 Justification 156,176

Key, field 97, 155 Keyboard-avoiding devices 83 Keyboards 3, 82, 175 Key-to-storage systems 55-6 Key transformation 103 Kilobyte (kb) 4, 18,36 Kimball tags 60

Languages 162-7 Laptop computers 8 Large scale integration (LSI) 6, 35 Laser cards 44 Laser disks 42-3 Laser printers 79-80 Layout checks 53 LCD (liquid crystal display) 82 Library subroutine 202 Light pens 58-9 Limit checks 53 Line printers 77-8 LISP 168 Load 9, 164 Local area networks (LANs) 129-32

line 130 ring 130 star 129

Local processing 124 Local variables 198 Location 23, 165 Log 109 Logical errors 190 Logic circuits 30 Logic diagrams 24--6 Logic gates 23 Logic hardware 24 Log in 109 LOGO 168 Loops 200 Low-level languages 152, 162-6

Machine code ins tructions 164-6 Machine language 152 Magnetic disks 4, 38--42 Magnetic ink character recognition

(MICR) 57-8 Magnetictape 4,36-8 Mailmerge 155, 242 Mainframe 6 Main memory 34 Management information system 256 Mantissa 21 Mark reading 56-7 Master fIle 101 Megabyte (Mb) 4, 18,36 Memory 4,34 Memory addressing 164 Memory address register 164 Memory data register 164 Memory management 151 Menu 52 Merging, of fIles 107 Metal oxide semiconductors (MOSs)

35 MicrofIche 84 MicrofIlm 84 Microprocessors, control applications

of 243--4 Minicomputers 6, 133 Mnemonic coding 55 Modems 125 Modes 81 Modulation 125 Module, of a program 185 Module exchange 244 Monitors 81 Motherboards 35 Mouse 83 MS-DOS 150 Multi-access 151, 240 Multiplexor 126 Multiprocessing 152 Multiprogramming 133, 151 Multitasking 151 Multi-user system 100

NAND gate 25 Narrow band 127 Nested loop 200 Networks 4, 128 NLQ 77-8 Non-impact printers 77 NOR gate 25 Normalisation 21 Notepad computers 82 NOT gate 24 Number systems 18-21

Object program 152 Octal numbers 18-19 Off-line 38, 55 On-line 55

data entry 55, 128 On-line databases 138-9 On-line processing 104, 151

Open subroutine 188 Open systems interconnection 124 Operand 164 Operating environments 153 Operating staff 278 Operating systems 150-2 Operation code 164 Operations manager 280 Operators 200 Operator's console 7, 278 Operators (people) 278 Optical character reader (OCR) 57-8 Optical mark reader (OMR) 56-8 Optical storage systems 42--4 Organisational chart (of a computer

department) 275 OR gate 24 OS/2 8 Output 3,76 Overflow 21

Packages 154-62 Packed decimal 23 Packet switching 127 Page description language 79 Page printers 77, 79 Pagination 176 Paging memory 36 Paper feeding 76 Parallel computers 4 Parallel running 266 Parameter 202 Parity check/bit 36, 141 Partition (of a disk) 40 PASCAL 22, 167 Passwords 109,278 Payroll 105-8 People in computing 279-83 Peripherals 3, 55 Personal micros 6 Phased chang-over 266 Photovideotex 134 Pixels 81-2, 160 Plotters 80-1 Point of sale (POS) systems 59-60

237 Polling 151 Portable micros 8 Precedence (of operators) 200 Presence check 53 PRESTEL 134-6 PRINT 199 Printer drivers 79 Printers 77-80

paper for 55 selection criteria for 101 spacing charts 264 types of 78--80

Printer server 130 Print quality 77 Private branch exchange (PBX) 128 Procedures 202 Process control 8, 244 Program counter 164

Program design 184 Program documentation 184, 188 Program flowchart 186-8 Program generator 189 Program generator modules 161, 184 Programmable read only memory

(PROM) 35 Programmers 277

productivity aids for 265 Programming 188--9,263 Programming languages 162-8 Programming projects 299-300

using existing software 300-1 Programming steps 183 Programming tasks 191-203 Programming teams 185 Programs 8, 244 Program testing 190, 265 Program writing, in BASIC 198--204 Project work (for your exam) 298-301

hints on 299 ideas on 305

PROLOG 168 Prompt 81 Protocol 127, 162 Prototyping 262 Pseudocode 266 PSTN 134

Query languages 101,157,167

Random access 36 Random access memory (RAM) 34,

154 Range checks 53 Read only memory (ROM) 35 Read/write memory 23 Real time 152, 243 Records (of a fIle) 97 Recovery (of a flie) 108 Reference fIles 102 Registers 164 Relative address 165 Relay 85 REMarks (in a program) 199 Remote job entry (RJE) 124 Replication 159 Report fIle 102 Report generator 157 Reserved words 198-9 Resolution 81-2 Response frame 137 Response time 124, 151 RGB 82 Ring networks 130-1 RISC 163 Robotics 244-6 Rogue values 200 Rounding 21 Run 9 Run time 190

Scanners 61 Screen dump 82

Screens 81 Scroll 82 Search 102, 135, 139, 157 Search and replace 175 Sector (of a disk) 39 Security (of files) 108-9 Seek time 39 Self-checking number 53 Semi-conductor memory 4, 35 Sensor 62 Sequence control register 164 Sequential coding 55 Serial access processing 36, 102, 104 Serial coding 54 Shared files 130 Sheet feeders 76 Shift leader 200 Sign bit 20 Sign and magnetic codes 20 Silicone chip 4 Simplex 127 Simulation 241 Single-user systems 151 Small business micros 8 Smart card 60 Soft-sectored disk 40 Software 3, 150-68 Software safeguards 109 Software systems 150-81 Sorting 105, 203-4 Source document conversion 51 Source program 152 Speech input 61-2 Speech output 84-5, 128 Spell checker 156 Spooling 152 Spreadsheets 158-60 Sprocket holes 76 Stand-alone 81, 122 Star networks 129 Statements 198-9 Stationery 76 Stepper motor 85, 244 Storage 4, 25

classification of 34-6 levels of 36 size estimation of 104

Storage capacity 36 Storage density 45 Storage systems 34-42 String 17,22 Structure charts 184-6 Structured program design 184-6

I

Structured pmgramming procedures 185

Sub programs 202 Sub routines 188, 202 Subscripts 203 Supercomputers 6 Supermarket (worked example)

267-8 Switching circuit 24 Symbolic address 166 Synchronous transmission 126 Syntax errors 189 Synthesised speech 129 System flow chart 187,230 System maintenance 267 Systems analysis 256-68 Systems design 261-3 Systems development manager 276 System software 150-4 System specification 262 Systems programmer 276 System study and analysis 259-60

Tables 98 Tags 109 Tapes 4, 36-8 Tape streamers 38 Telecommunications 5, 126 Telesoftware 136 Teletext 136 Teletypes 126 Teleworker 227 Telex 136 Terminal emulation software 124 Terminals 81, 145, 150 Teminator (of data) 10 Test data 191,265 Testing (of program) 189-90 Text editor 156 Thermal printers 78 Thin-film memories 44 Time-sharing 151 Time-slice 151 Top-down 184 Touch-screen 83 Trace routine 190 Trace table 9, 153 Track 38 Tractor feed 76 Training for IT 280 Transaction file 101, 106 Transaction processing 123 Transaction terminals 126 Transcription error 53 Transistors 24, 85 Transport system control 244

Transputer 4 Trruncation (of numbers) 21 Truth tables 23-6 Turnaround document 57 Turnkey system 263, 279 Turtle 244 Twos complement 20 Type check 53

Unconditional branch 165,200 Unemployment 281 UNIX 151 Updating (offiles) 102 User identification (lD) 109 User-orientated Languages 167 Utilities (or service) programs 153

Validation 105 Value and network (VAN) 138 Variable 198 Verification 52,55, 105 Video digitisers 61 Videodisk 42 Video signal 82 Videotex 132 Viewdata 132 Virtual storage 36 Visual display units (VDUs) 4, 81

126 VLSI (very large scale integration) 24 Voiceband 127 Voice output 108-9 Voice recognition 61-2 Voice response systems 128 Volatile memory 35 Volume testing 265

Wide area network (WAN) 129,242 WIMP 153 Winchester disk 40 Windows 153 Word 17 Word addressing 23 Word lengths 17,23 Word processing 155 Work file 102 Workstation 81 WORM 42 Writing pads and tablets 61 WYSIWYG 82

X25 128

Zone bit 22

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