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1188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Software
2188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Hardware
Software brings the machine to life When a computer is using a particular program, it
is said to be running or executing that program. Two major categories of software
System software, i.e., Operating System Application software
SystemSoftware
ApplicationSoftware
234525543089...
Useful outputReal-world tasks
3188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Operating Systems The operating system tells the computer how to
interact with the user and how to use devices such as the disk drives, keyboard, and monitor. The operating system is continue to run until the computer is turned off.
When a computer is turned on, it goes through steps to prepare itself to run user's application: Run system software located in ROM BIOS. Next, the computer runs the operating system in
diskette, hard disk, or other storage devices. After the computer finds and runs the operating
system, the user can issue commands to the computer.
4188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Application software Application software is a program that help
people accomplish specific tasks. Thousands of application are available; however
some major categories that likely to be encounter are: Word processors Spreadsheets Database management software (DBMS) Multimedia, graphics and presentations Utilities Communications
5188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Word Processors
6188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Spreadsheets
7188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Graphics
8188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Presentations
9188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Data
10188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Transforming Data into Information Computers cannot understand anything about us.
All they can do is recognizing two distinct states produced by electricity, magnetic polarity, or reflected light.
All they can understand is whether a switch is on or off. The CPU consists of several million tiny electronic switches
called transistors. A computer assembling its individual on/off switches into
patterns that are meaningful to us. In strictest sense, data consists of the raw numbers that
computers organize to produce information. Computers turn raw, separated data into meaningful
information.
11188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Data and Information
12188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
How Computer Represents Data To a computer,
everything is a number.
For computer, the sentence "Here are some words" is represented by:
Here
are
some
words
0100 10000110 01010111 00100110 01010010 00000110 00010111 00100110 01010010 00000111 00110110 11110110 11010110 01010010 00000111 01110110 11110111 00100110 10000111 0011
13188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Number Bases A number base is a specific collection of symbols
on which a number system can be built. The number base familiar to us is base 10, upon
which the decimal number system is built. There are ten symbols, 0 through 9, used in decimal system.
When we need to represent a number greater than 9 we use two symbols together; as 9 + 1 = 10.
Each symbol in a number is called a digit, so 10 is a two-digits number.
14188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Other Number Systems Binary: Base 2 Octal: Base 8 Hexadecimal: Base 16
15188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Number Base Systems
Decimal Binary Octal Hexadecimal
0123456789101112
01101110010111011110001001101010111100
012345671011121314
0123456789ABC
16188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
(cont'd.)
Decimal Binary Octal Hexadecimal
13141516171819202122232425
11011110111110000100011001010011101001010110110101111100011001
15161720212223242526273031
DEF10111213141516171819
17188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Numbers in a computer In a computer, all data must be reduced to
electrical switches. A switch has only two states --”ON” or “OFF” -- so it has only two numeric symbols. 0 stands for “OFF”, and 1 stands for “ON”.
Computers function in a binary number system (base 2).
When a computer needs to represent a quantity greater than 1, it uses the second digit.
18188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Bits and Bytes When referring to computerized data, each
switch -- whether on or off -- is called bit. The term bit is a contraction of binary digit. A bit is the smallest possible unit of data.
To represent anything meaning -- that is to convey information -- the computer needs groups of bits.
The larger unit of data is the byte, which is a group of 8 bits.
19188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
(cont'd.) With one byte, the computer can represent up to
256 different values because it is possible to count from 0 to 255 with 8 binary digits (one byte).
One byte combination is an enough unit to represent all the (English) characters on the keyboard, including all letters (uppercase and lowercase), numbers, punctuation marks, and other symbols.
20188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Character Codes The programmers need a standard code which is
group of numbers to represent or stand for letters of the alphabet, punctuation marks, and other symbols. ASCII Unicode
21188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
ASCII The American National Standard Institute (ANSI)
solution to represent the symbols with bits of data was the ASCII character set. ASCII = American Standard Code for Information
Interchange Today ASCII is the most common character set
used. ASCII is the seven bits code. The ISO (International Standard Organization)
standard expanded on the ASCII character set, to offer different sets of characters for different language group.
22188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
(cont'd.)
Dec Hex Code32333435363738394041424344454647
202122232425262728292A2B2C2D2E2F
space!“#$%&'()*+,-./
Dec Hex Code Dec Hex Code4849505152535455565758
64656667
303132333435363738393A..
40414243
0123456789:
@ABC
686970
90919293949596979899
100101
404142..
5A5B5C5D5E5F606162636465
DEF
Z[\]^_`abcde
23188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Unicode Unicode Worldwide Character Standard
represents each symbol by two bytes --16 bits. With two bytes, a Unicode character can be any
one of more than 65,536 different characters or symbols.
Many software publishers, including Microsoft, Netscape, and Accent, encourage their developers to use Unicode in their programs.
24188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Users Job related to computer
Computer engineers System administrators Network administrators System analysts Programmers Software testers System maintainers
25188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
(cont'd.) Many jobs use computer as a tool.
Accountants Draftsmen Animators Data entry worker Customer support specialists
26188 110 Computer Programming : Chapter 1.3 – Software | Data | Users
Responsibility of the users Keep computer from malicious software
Virus, worm, trojan, spam, internet fraud Anti virus/spyware Update software, patches
Recognize limitations of computer systems Hardware errors ~ design error, hardware failure Software errors ~ OS, applications Applying wrong ways
Use computer for working The Computer Crime Act B.E. 2550