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Chapter 2. Technology. Computer categories. O’Brien 48. Traditional categories: small , mid-range and large mainframes and super computers Application categories: host-computers, database servers, transaction systems and central systems. Mainframes. Traditional categories:
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Chapter 2 Technology
Computer categories O’Brien 48 • Traditional categories: • small , mid-range and large mainframes and • super computers • Application categories: • host-computers, database servers, • transaction systems and central systems Mainframes • Traditional categories: • minicomputers, mid-rang systems • Application categories : • departmental systems, network servers, technical • workstations , workgroup systems Minicomputers • Traditional categories : • portable , desktop and minitower-computers • Application categories : • personal computers, multi-user systems, netwerk-servers • technical , office and professional workstations Microcomputers
Trends in Computer Characteristics Generation Fist Second Third Fourth Fifth Size Room Closet Desk Dessktop Credit card? Circuitry Vacuum Tubes Transistors IC’s LSI’s VLSI ReliabilityHours Days weeks Months Years? Instuct/secHundreds Thousands Milions Tens of millions Billions? Memory Thousands 10s Thousands 100s Thousands Millions Billions? Price/M instr $ 10 $ 1.0 $ 0.1 $ 00.01 $ 0.0001? O’Brien p 50
Categories • Microcomputers or personal computers • Midrange computers or minicomputers • Mainframe computers • Supercomputers • Computer Networks • client/server systems • network computers O’Brien 51-54
Client/Server Host system super server Client Server • types • Functionality O’Brien p 55
Multimedia Computersystemen O’Brien p 56
Multimedia • Technologies : Languages HTML, JAVA • Hypertex • Hypermedia • Elements • CDI compact disk interactive • Compressed audio • Computer edit systems • Digital audio • DVI digital video interactive • MIDI musical instrument digital interface • Sound card • Video capture card O’Brien p 57-58
Input device inputs data and instructions into the CPU Output device Design of a computer system O’Brien 60 Central processing unit CPU Control Unit Translates instructions and manages processing Arithmetic/Logical unit (ALU) Executes arithmetic operations and compares Internal storage unit Stores data and instructions during execution • Keyboard • mouse • touch screen • optical scanner • light pen • speech input • barcode • .... • video screen • printer • loudspeaker • video • ... External storage Stores data and programs for the applications
Peripheral Devices O’Brien 63 - 79 • terminals • video, hand terminals, intelligent terminals, transaction-terminals (POS), ... • Pointing devices • pictogram, mouse, trackball, joystick, touch-sensitive, light pen, graphical tablet • Terminal input/output • LCD, plasma, video-output, impact printers, laser printer, inktjet printer • Speech input/output • Optical and magnetic recognition (OCR , MICR) • Storage: tape, magnetic disk , optical disk (ROM , WORM)
The “Von Neumann” Computer I N T E R F A C E I N T E R F A C E Data memory R E S U L T S Arithmetic unit D A T A Control unit Program memory Programmer Interface
Computer Architecture Input and Output Converters translate the external representation into an internal representation or the other way around. eg: keyboards, video screens , printers, barcode readers, magnetic cards, sensors, ... Data memory Temporary storage of data . intermediate results ( eg. program variables ) . input/output buffers
Computer Architecture 2 Program memory Contains the instructions that go via the program interface to the CPU and that will be executed one by one. Central memory A set of numbered cells that can contain a binary number. Terminology: . word . address Program variables represent an address
Central Memory 00 01 02 03 04 05 06 address contents 10 11 12 13 14 15 20 21 22 23 24 25 In most computers , data memory and program memory are only logically separated
Storage Primary RAM ROM Semiconductor memory Access speed increases Storage capacity decreases Cost/byte increases Magnetic disks Secondary Magnetic tape Optical disk Tekst: O’Brien p 74
Computer Architecture 3 Arithmetic and Logical Unit This unit is responsible for the processing of the data read from, and rewritten into the data memory. The unit can compare the contents of memory cells and execute basic operations. The Control Unit This unit reads the instructions one by one from the program memory , decodes them and sends the appropriate signals to the other components.
Peripheral Memory . Uses no electrical energy . Usually stored in blocks of hundreds of words , which are moved as one block into the central memory . Magnetic material in permanent movement - disk memory < 1/10 sec : allows " random access " - Magnetic tapes : sequential memory . Optical material - CD-ROM : to distribute large amounts of data - WORM : archiving
Usage of Memory Price per bit Access Time Registers Registers: Very fast memory ( < 100 ns ) in arithmetic and control unit Central memory: ( between 50 and 500 ns ) These types of memory use integrated circuits and use electrical energy. The content is lost with a power supply interruption. central memory Mass storage ( disk - tape )
Memory capacity Kilobyte: one thousand bytes Megabyte: one million bytes Gigabyte: one billion bytes Terabyte: one trillion bytes Time Millisecond: one thousandth of a second Microsecond: one millionth of a second Nanosecond: one billionth of a second Picosecond: one trillionth of a second Units O’Brien 61
Memory Access Time price 100 I.C. 10 1 Disk Tape CD-ROM -8 -6 -4 -2 10 10 10 10 1s access time
Coding Data Numerical Data - integer : binary numbers 1. 2 + 0. 2 + 1. 2 + 0. 2 + 1. 2 = 10101 b = 21 d - real numbers mantissa and exponential part 4 3 2 1 0
ASCII computer codes O’Brien 61 char dec hex oct binary char dec hex oct binary A 065 41 101 01000001 B 066 42 102 01000010 C 067 43 103 01000011 D 068 44 104 01000100 E 069 45 105 01000101 F 070 46 106 01000110 G 071 47 107 01000111 H 072 48 110 01001000 I 073 49 111 01001001 J 074 4A 112 01001010 K 075 4B 113 01001011 L 076 4C 114 01001100 ..... 0 048 30 060 00110000 1 049 31 061 00110001 2 050 32 062 00110010 3 051 33 063 00110011 4 052 34 064 00110100 5 053 35 065 00110101 6 054 36 066 00110110 7 055 37 067 00110111 8 056 38 070 00111000 9 057 39 071 00111001 : 058 3A 072 00111010 ; 059 3B 073 00111011 .....
Complex Configuration LAN/WAN Remote Data Base
Hardware Schema Microcomputer Central Microprocessor Supporting Microprocessor RAM ROM other system management and equipment Internal memory System bus Keyboard Interface Display Interface CD-ROM Interface Serial Interface Diskdrive Interface Parallel Interface ... ... Keyboard Video screen CD-ROM Modem Diskette station Printer
opc. = operation code op.1 = address in memory of the first operand op.2 = address in memory of the second operand next = address in the program memory of the next instruction next1 = address of the next instruction if a condition is true next2 = address of the next instruction if a condition is false Instructions Information processing instructions opc. op.1 op.2 res next Control instructions opc. op.1 op.2 next1 next2
Program Example Computer controlled door Data memory Arithmetic unit Control unit Program memory Programmer Interface
Computer Controlled Door D1 P2 D2 P3 P3 P4 D2 P5 D2 P6 D1 P7 P3 P8 P1 P9 DDA P1 1 2 3 4 5 6 7 8 9 STO STO EQ? MUL ADD ADD NE? NE? STO 0 0 KFL D2 D2 D1 D1 D2 1 - - 0 10 KDA 1 3 207 - KFL key flag KDA key data DDA door data D1 number of digits read D2 value read
Usage of P-register Control Unit P - register or ordinal counter +1 P-register I-register Program Memory Information processing instructions opc. op.1 op.2 res opc. op.1 op.2 next Control instructions
Door program with P-register - - 0 10 KDA 1 3 207 - - 1 2 3 4 5 6 7 8 9 10 STO STO EQ? MUL ADD ADD NE? NE? STO JMP 0 0 KFL D2 D2 D1 D1 D2 1 - D1 D2 P3 D2 D2 D1 P3 P1 DDA P1
Client server Clients comm. server DB. server DB. server Clients comm. server DB. server O.A. server