操作系统第一章课件

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Network operating systems and distributed operating systems
• Network operating system:
– The users are aware of the existence of multiple computers and can log in to remote machines and copy files from one machine to another, each machine runs its own local operating system and has its own local user (or users)
• 1.2.2 Second generation (1955-1965) Transistors and batch systems
– Typical OS:FMS(the Fortran monitor system) and IBSYS (IBM’s operating system for the 7049);
• Micro-architecture level: in which the physical devices are grouped together to form functional units, this level consists of:
– Registers internal to the CPU – A data path containing an arithmetic logic unit: on some machines, the operБайду номын сангаасtion of the data path is controlled by software, called the micro-program
• 1.1.2 the operating system as a resource manager[※※※※]
– Each program gets time with the resource: Different programs take turns to use resource – Each program gets space on the resource: Each get parts of the resource
• Distributed operating system:
– Like a traditional single-processor system, even though it is composed of multiple processors. The users should not be aware of where their programs are being run or where their files are located; that should all be handled automatically and efficiently by the operating system
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The Operating System Zoo
• 1.3 the operating system zoo • Some important operating system:
– – – – – – – Mainframe operating systems Server operating systems Multiprocessor operating systems Personal computer operating systems Real-time operating systems Embedded operating systems Smart card operating systems
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User mode and kernel mode
• Kernel mode (supervisor mode): [※※※※]
– The programs in it can be protected from user tampering by the hardware – The operating run in it
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personal computer
• 1.2.4 the fourth generation (1980-present) personal computers
– With the development of LSI(large scale integration) circuits,the age of the personal computer dawned – CP/M,MS-DOS: based on users typing in commands from the keyboard – Windows,Linux/Unix: use GUI,and are user friendly – Windows95,Windows 98:still contain a large amount of 16-bit Intel assembly language – Windows NT:a full 32-bit system – Unix/Linux:strongest on workstations and other high-end computers, such as network servers – Unix/Linux: true multi-users,multi-tasks OS
• User mode: [※※※※]
– Compilers and editors run in user mode – If a user does not like a particular compiler, he is free to write his own
• The distinction between kernel mode and user mode, however, is sometimes blurred in embedded systems and some other systems
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Physical devices and micro-architecture level
• Physical devices consists of :
– – – – Integrated circuit chips Wires Power supplies Cathode ray tubes, and so on
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Machine language
• Machine language (instruction set architecture) it consists of:
– The hardware – Instructions visible to an assembly language programmer
– Dos,windows,Linux,and so on
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Early batch systems
cards 1041
Input cards
7049
output cards
1041
Print output
1.1.2 the second generation(1955-1965) transistors and batch systems (offline) • Early batch system – Programmers bring cards to 1401 – 1401 reads batch of jobs onto tape – Operator carries input tape to 7049 – 7049 does computing – Operator carries output tape to 1401 – 1401 prints output
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Structure of a typical FMS job
• Structure of a typical FMS job – 2nd generation
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multiprogramming
• 1.2.3 Third generation (1965-1980) ICs (integrated circuits )and multiprogramming • Multiprogramming system
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Timesharing and spooling
• Timesharing: each user has an online terminal,the CPU can be allocated in turn to the jobs that want service • Spooling: read jobs from cards onto the disk as soon as they were brought to the computer room – whenever a running job finished ,the OS could load a new job from the disk into the now-empty partition and run it
• The function of machine language:
– Moving data around the machine – Doing arithmetic – Comparing values
• The I/O devices are controlled by loading values into special device registers
Introduce
• • • • • • 1.1 What is an operating system 1.2 History of operating systems 1.3 The operating system zoo 1.4 Computer hardware review 1.5 Operating system concepts 1.6 System calls