Presentation on theme: "What is a computer? –A computer is a device capable of performing computations and making logical decisions at speeds millions and even billions of times."— Presentation transcript:
What is a computer? –A computer is a device capable of performing computations and making logical decisions at speeds millions and even billions of times faster than those of human beings. Computers process data under the control of sets of instructions called computer programs. These programs guide computers through orderly sets of actions that are specified by individuals known as computer programmers.
Computer Organization –Central processing unit (CPU) Arithmetic and logic unit (ALU) Control unit (CU) –Memory unit –Input unit –Output unit Secondary storage unit
Computer hardware history First generation, 1940s –Vacum tubes: cost, size, energy requirements Second generation, 1950s –Transistors –Programming languages were developed Third generation, 1960s –Integrated Circuit (IC) Future –More computing power, smaller, more reliable, faster, cheaper, networked –Programmers needed to write new programs –Programmers needed to update older programs
Evolution of Operating Systems Single-user batch processing Operating systems (software) were developed Multi-programming Timesharing UNIX (C was developed to write it)
Programlama Nedir? Programming is the ability to talk to the computer in a language it can understand and using grammar and syntax that it can follow to get it to perform useful tasks for you. You write code and the computer interprets your request and does something. Doing something is a vital part of programming. Step-by-step instructions
Programlamanın Erken Tarihçesi 1822, Charles Babbage –Difference machine: a single-purpose machine that could ultimately only carry out one operation –Analytical engine: This engine would contain the basic components of a modern computer and led to Babbage’s being called the “father of the computer.” an inability to clearly document and convey his ideas!
Programlamanın Erken Tarihçesi 1854, Charles Boole –Described the symbolic logic system 1890, A.B.D. Nüfus sayımı –necessity is the mother of invention –data processing equipment 1946, ilk programlama dili “Plankalkül” –By Konrad Zuse, for Z-3 computer –Birth of modern programming
Programlamanın Erken Tarihçesi 1945, “bug” kavramının doğuşu –“debugged” –“debugging a computer” –“debugging a computer program” 1949, development of “Short Code” –code had to be made into machine-readable code by hand
Programlama Dilleri Makine dili Assembly dili Yüksek düzeyli diller
The difficulty of a programming language comes down to how far it is removed from natural written language.
Makine dili Any computer can understand only its own machine language directly This machine language is defined by the computer’s hardware design Consists of streams of numbers Machine dependent Makine dili örnek kodu 01000110 11000100 10111011 00011101
Assembly Dili Makine dili yavaş, sıkıcı ve hataya açık English-like abbreviations to represent the elementary operations of the computer These abbreviations formed the basis of assembly languages Translator programs called assemblers convert assembly lanuage programs to machine language Assembly dili örnek kodu ADD A, 6 MOV A, OUT LOAD B SUB B, A
Yüksek düzeyli diller Assembly languages still required many instructions to accomplish even the simplest task To speed up the programming process, high- level languages, in which single statements accomplish substantial tasks, were developed. Translation programs called compilers convert high-level language programs into machine language. Looks almost like everyday English Yüksek düzeyli dil örnek kodu Sayı3 = Sayı1 + Sayı2
Yüksek Düzeyli Dillerin Gelişim Süreci 1954-1957, Fortran (by IBM), for creating scientific and engineering applications, first commercial high-level programming lang. 1959, Cobol, Commercial applications requiring manipulation of large amounts of data Late 1960s, Pascal, for academic use New offerings build on aspects of their predecessors 1967, BCPL, for writing OSs, software, compilers 1970, B, early versions of UNIX 1973, C, UNIX, major operating systems 1975, BASIC 1980s, C++, object-oriented programming (OOP) 1995, Java, create dynamic content for Web pages and for consumer devices 2000, C#, designed specifically for the.NET platform
Neden bir çok programlama dili var? each type of computer (hardware) really only understands one language –001110100011001010110010001101001011011110111010101 110001100100000011000010110111001100100001000000110 100101100110001000000111011101100101001000000110100 001100000011010010110111000100000011000100110100101 101110011000010111001001111001001000000011101110110 100101110100011010000010000011011110111010101110010 001000001100011011011110110110101110000011101010111 010001100101011100100111001100100000111010101110011 011010010110111001100111001000001101001011101000010 000001100001011 A program (either an interpreter or a compiler) is required to convert the code from text into a binary language that the computer can decipher.
Programs needed to create programs –Development Environment: A development environment is a program that you use to type the code into. –Compiler: A compiler is a program that changes the code you type into code that the computer can understand.