Isletim Sistemi Tarihçesi

• ILK NESIL iSLETIM SISTEMLERI (1945 – 1955)

1940 larda Howard Aiken, John von Neumann, Jpresper
Eckert ve William Mauncley VAKUM TÜPLERI kullanarak
ilk hesap yapabilen motorlar üretmislerdir.

Von Neumann architecture
The term Von Neumann architecture, also known as the Von Neumann model or the Princeton architecture, derives from a 1945 computer architecture proposal by the mathematician and early computer scientist John von Neumann and others
This describes a design architecture for an electronic digital computer with subdivisions of a processing unit consisting of an arithmetic logic unit and processor registers, a control unit containing an instruction register and program counter, a memory to store both data and instructions, external mass storage, and input and output mechanisms
http://en.wikipedia.org/wiki/Von_Neumann_architecture



The Von Neumann architecture has been incredibly successful, with most modern computers following the idea.
You will find the CPU chip of a personal computer holding a control unit and the arithmetic logic unit (along with some local memory) and the main memory is in the form of RAM sticks located on the motherboard.
But there are some basic problems with it. And because of these problems, other architectures have been developed.
http://www.teach-ict.com/as_as_computing/ocr/H447/F453/3_3_3/vonn_neuman/miniweb/pg3.htm


The Von Neumann architecture:
The Von Neumann architecture is a design model for a stored-program digital computer.
Its main characteristic is a single separate storage structure (the memory) that holds both program and data.

Some important features of the Von Neumann architecture are:

1. both instructions (code) and data (variables and input/output) are stored in memory;
2. memory is an collection of binary digits (bits) that have been organized into bytes, words, and regions with addresses;
3. the code instructions and all data have memory addresses;
4. to execute each instruction, it has to be moved to registers;
5. only the registers have the “smarts” to do anything with the instructions; memory locations have no “smarts”;
6. to save a result computed in the registers, it has to be moved back to memory;
7. the granularity of instructions at the machine or assembler level is much smaller than the granularity at the MATLAB programming language level; that is, each MATLAB instruction corresponds to many machine instructions;
8. operating systems and compilers keep the instructions and data in memory organized so it doesn't get mixed up together;
9. if a program execution goes past its legal last instruction (for example) it can overwrite other instructions/data in memory and cause strange things to happen;
10. one of the advantages of modern operating systems and compilers is the concept of relocatable code — that is, code that can be loaded and run from any location in memory.

http://last3.in/2010-11/CSE101/lectures/10-von-neumann-notes.html

• IKINCI NESIL, TRANSISTÖRLER VE TOPLU  IS(BATCH) SISTEMLERI

Bu makineler müsterilere satilabilecek hale ve
güvenilirlige gelmislerdi. Çok pahali oldugu için büyük
kurumlar, devletler ya da üniversiteler alabiliyordu.
Bir is yaptirmak için program FORTRAN ya da
ASSEMBLER ile bir kagida yazilir. Sonra bu program
delikli kartlara aktarilir. Bu kartlar sirasiyla makinelerde
isletilirdi.

• ÜÇÜNCÜ NESIL (1965-1980) ENTEGRE DEVRELER VE ÇOKLU PROGRAMLAMA (Multi Programming)

Eskiden bir is çalisirken I/O nedeniyle beklediginde baska
bir is çalismazdi. OS/360 ile bellek birden fazla parçaya
ayrilmis ve her parçada baska isin çalismasi saglanmistir.
Bir isin çalismasi I/O için askiya alindiginda, bellekteki
baska bir ise geçilirdi.
Diger yeniligi kartlardaki programlari diske okumasi ve
programlari diskten yüklemesidir

• DÖRDÜNCÜ NESIL  (1980-1990) KISISEL BILGISAYARLAR

LSI(Large Scale Integration) büyük ölçekli entegre
devrelerin gelistirilmesi ile (1 cm slikon üzerinde yüzlerce
transistör vardir) kisisel bilgisayarlar üretilmistir


http://members.comu.edu.tr/msahin/courses/isletim_sistemi_giris/ders02.pdf

• An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. 

https://en.wikipedia.org/wiki/Operating_system

• An operating system is a program that acts as an interface between the user and the computer hardware and controls the execution of all kinds of programs.

Following are some of important functions of an operating System.

    Memory Management

    Processor Management

    Device Management

    File Management

    Security

    Control over system performance

    Job accounting

    Error detecting aids

    Coordination between other software and users

https://www.tutorialspoint.com/operating_system/os_overview.htm

• An operating system is a set of programs that lies between applications software and the computer hardware. Conceptually the operating system software is an intermediary between the hardware and the applications software.

An operating system has three main functions: (1) manage the computer's resources, such as the central processing unit, memory, disk drives, and printers, (2) establish a user interface, and (3) execute and provide services for applications software.

https://homepage.cs.uri.edu/faculty/wolfe/book/Readings/Reading07.htm

• Computer = HW + OS + Apps + Users

OS serves as interface between HW and ( Apps & Users )

OS provides services for Apps & Users

OS manages resources ( Government model, it doesn't produce anything. )

https://www2.cs.uic.edu/~jbell/CourseNotes/OperatingSystems/1_Introduction.html