Department of Computer Science
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Faculty of Civil Engineering, Brno University of Technology
INFORMATION
TECHNOLOGY
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code of course: BU01
Content of course
• Introduction - 4 lectures
•how computers work
•how PCs work
•peripheral devices
•computer networks
•algorithm, program, data
• Operational systems - 2 lectures
•classification and global properties
•standard OS: file system, processes, policies
•using Unix, Windows
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Content of course - cont.
• Text processing - typography
•Principles of computer typography - 1 lecture
•WYSIWYG text processing and DTP (MS Office)
- 6 practices
•Markup languages (HTML) – 5 practices
• Computer graphics and image processing
• Databases and spreadsheets
•Principles of data modeling and database systems
- 1 lecture
•Calculations in spreadsheet environment
- 5 practices
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Basic Information
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• http://www.fce.vutbr.cz
• student server http://study.fce.vutbr.cz )
• computer classrooms – in winter change one's shoes!
• Lectures: classroom B432, typically Tuesday 16:00
• Practices: B427, typically Monday 16:00
• Tests and credit:
•Simple calculation in MS Excel
•Knowledge testing of information technology
Department of Computer Science
Faculty of Civil Engineering, Brno University of Technology
How do the computers work
Goal: unification of knowledge of technologies used in
computer science
Approach: great simplification
Content:
• CPU and operational memory - main parts of
computer
• instruction processing in computer
• main computer architectures
• CPU and memory communication
• peripheral devices and their controllers
• permanent and external memory
• program and machine code
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Main parts of computer
Basic information structure
7.
6.
5.
4.
3.
2.
1.
0.
0
1
0
1
1
0
0
1
5
9
Byte (59Hex = 89Dec)
Address
Content
00000000
01001011
00000001
10000010
00000010
01001111
00000011
10101011
00000100
00001000
Bi-directional
communication
CPU
RAM
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Instruction cycle
Address
Content
Phases of cycle
00000000
01001011
• Instruction fetching
• Instruction decoding
• Instruction performing
00000001
10000010
00000010
01001111
00000011
10101011
00000100
00001000
CPU
Instruction table of CPU
Content
00000000
00000001
00000010
What to do
No operation
Jump over next address
...
RAM
Input-Output
devices
• Each
device has its own controller
that transforms the other
type of information into binary one
• Controller accesses to the partial part of RAM
• Device types:
• Write only to the memory - input device (e.g. keyboard)
• Read only from the memory - output device (e.g. monitor)
• Read/write - input-output device (e.g. disk memory)
RAM
• Direct communication between CPU and controller - I/O
ports
CPU
Peripheral
device
controller
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Architecture according to Von Neumann
• Computer consists of processing unit, memory and
I/O devices
• Computer structure is not depended on the solved
problem
• Memory is divided into the same cells. Access to the
cells is enabled through their addresses
• Cells of memory contain both instructions and
data distinguishable only by context
• Program is composed of sequence of instructions
executed step by step excluding jumps
• Addresses, instructions and data are represented in
binary form
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Central processing unit
Arithmetic-logic
unit
Controlling unit
Registers
Instructions
Data
RAM
CPU
Instructions
• transfer - moving data between registers of CPU
and cells of RAM
• arithmetic - adding, subtracting, multiplying, …
typically operate with data in registers
• logic - log. conjunction, disjunction, rotation, shift, …
typically operate with data in registers
• jumps - condit. commands, calling subroutines, …
• input-output - moving data between registers of CPU
and I/O ports of controllers of peripheral devices
• others - controlling, …
CISC (Complex Instruction Set Computer)
RISC (Reduced Instruction Set Computer)
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Memory
• Device for storing the information (binary encoded
data and instructions)
• Capacity of memory (amount of storable
information) is measured in bytes
• Memory is divided into the same cells - minimal
addressable units
• Two types of memory:
• operational (internal) - main part of computer
realized by integrated circuits. Depends on the
source of el. energy.
• peripheral (external) - stores data permanently,
information is not accessible directly by CPU.
Cheaper, slow (disks, CD-ROM, floppy, ZIP, …)
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Caches
Operational memory
Magn. disk
Magn. tape, (optical disk)
Access time increases
Registers
Capaity incerases
Cost of bit increases
Memory hierarchy
Units for capacity of memory
Prefixes used for multiply coefficients slightly differ
from the ones in SI standard:
1 KB = 210 B = 1 024 B,
1 MB = 220 B = 1 048 576 B = 1 024 KB,
1 GB = 230 B = 1 073 741 824 B,
1 TB = 240 B = 1 099 511 627 780 B.
64 KB = 65 536 B, 512 KB = 0,5 MB, …
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CPU - RAM communication
Internal bus
CPU
RAM
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I/O control.
data
address
control
Internal (system) bus
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• Set of conductors with el. signals
• Three parts of bus with signals of the same meaning
•Data part - transfer of data between CPU and RAM,
16, 32, 64 bits wide corresponding to the type of processor
•Address part - transfer of addresses from CPU to RAM,
16-64 bits wide determines limit capacity of memory
•Controlling part - controls the flow of information through the
bus
• Asynchronous commun. (handshaking on contr. part):
•CPU: I have the address for you on the address part of bus
•RAM: I have the data (content of address) for you on the data
part of bus
• Synchronous communication (preferred):
• Independent bus clock determines the phases above
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Generation of computers
Possible classification according to the used
components
Gener.
Year
Basic component
Speed
(Instr./s)
0.
1940 Relay
<10
1.
1950 Electron tube
<1.000
2.
1958 Transistors
<10.000
3.
1964 Integ. circuits
<100.000
3½.
1972 LSI
<1.000.000
4.
1981 VLSI
<109
Bugs in computer software
Grace Murray Hopper, working in a temporary World
War I building at Harvard University on the Mark II
computer, found the first computer bug beaten to
death in the jaws of a relay. She glued it into the
logbook of the computer and thereafter when the
machine stops (frequently) they tell Howard Aiken
that they are "debugging" the computer. The very first
bug still exists in the National Museum of American
History of the Smithsonian Institution. The word bug
and the concept of debugging had been used
previously, perhaps by Edison, but this was probably
the first verification that the concept applied to
computers.
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Bugs in computer software
„First actual case of bug being found.“
September 9th, 1945
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Beginning of computers
Electr. computer
ENIAC (1945)
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•
•
•
17 648 elect. tubes
mass 30 t
supply 140 kW
cooled by two
aircraft motors
• programmable through jumpers on the spec. desk panel
• till 1946 top secret
• Electronic Numerator, Integrator, Analyzer and Computer
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Program and subprogram
programmer
Native
language
compiler
Programming
language
Instructions
for CPU
(machine
code)

Procedural languages
(Algol, Fortran, Pascal, C, C++, …)
 Nonprocedural languages
(Prolog, Lisp, query languages, …)
 Interpreted languages
(Basic, Java, Pearl, …)
Realization of subprogram in machine code - stack
Advantages of using subprogram
•memory saving
•well arranged programming
•mechanisms of interrupt
Disadvantages
•slightly slower
Literature
• http://www.maxmon.com/history.htm
• http://www.cs.virginia.edu/brochure/museum.html
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