Operating system

memory

it disappears when power is turned off.

Part of CPU

the ALU is where data is processed either by manipulating it or by acting upon it: it has two parts: Arithmetic part - which does exactly what you think it should - it performs the calculations on the data e.g. 101 + 11 = 1000 5 + 3 = 8 Logic part - deals with logic and comparisons. For example, it works out if one value is greater, less than or equal to another.

What is an operating system?

the software you see hen you turn on the computer and the last software you see when you turn off the computer.

types of memories

-DRAM -SRAM -SDRAM

Which is the function of an OS?

-Handles Input and Output ( I/O ) -Establishes the User Interface and Device drivers -Manages Programs and Manages Memory

Which of the following is are an example of a use for Cache Memory?

-Instruction Register (IR) -Memory Address Register (MAR) -Arithmetic Logic Unit (ALU)

Which of the following is TRUE regarding operating systems?

-Operating systems manage things such as CPU processor, memory, and disk space -provides a stable and consistent operating environment -The operating system acts as a traffic cop, a translator, and a resource manager. -The operating system mediates interactions among both internal and external components. -They manage the hardware and software resources of the computer system. - manage software

CPU

-can only do one thing at the time unless it is multicore!

which step are involved in Von_Neumann cycle?

-decode -update instruction counter

What form of memory (short term storage) cannot be changed on the motherboard?

-ssd Hard drive -cache memory

The Hyper link needs pentium __ chips which make a physical CPU show as two logical CPU's. Fill in the blank

4

What is a boot loader? What is a form of a boot loader that stays present after the OS loads?

A program that loads other software for the OS to start; BIOS.

What is one of the functions of the kernel?

Assigns task priority

Which program loads other software for the operating system to start?

Boot Loader

Which is true about Cache Memory?

Cache Memory stores the most recent data the CPU has accessed from RAM. use: Arithmetic Logic Unit The control unit the interface unit

Different interface

Command-Line - syntax is important, has keywords and requires lots of typing; e.g., DOS Menu-Driven - text based, pick items from a list using arrow keys and Enter. Graphical (GUI) - uses icons, mouse to point and click on items; e.g., Mac, Windows

Von-Neumann Concept

Control Unit: The Control Unit interprets instructions of the program and controls the other parts of the processor. Instruction Register: stores actual instruction which was loaded from memory before. Instruction Counter: stores memory address of the following instruction. Is incremented automatically after every command. Status Register (flags): information about the result of the last operation is stored here. Some instructions do different things depending on the flags. Decoder: reads the actual instruction and uses the flags if needed to find out what is to do. Signal Generator: here the commands for the other parts of the processor are generated. Execution Unit: The execution unit is the core unit of the processor. The arithmetic logic unit calculates (ALU), the registers are a very fast memory to keep the operands that are needed for the actual operation. Memory: The memory stores both data and instructions of the actual program. Data can be read and written to variable addresses. I/O Unit: Input from the environment, and output of the results are managed here.

Functions if OS

Handles Input and Output ( I/O ) Establishes the User Interface Manages Programs Manages Memory Device drivers example: UNIX Mac DOS Window XP Windows 7 Linux

The kernel can be described as the ________ of the modern Operating System.

Heart The kernel allocates resources to the other parts of the OS: Amount & Address of Memory Assigns task priority Determines cycles of operation needed Device I/O drivers Communication & Synchronization

What is the main goal of operating systems and are they necessary?

It combines/manages hardware and software resources, they are necessary for software to work

Hyper-Threading

Hyper-Threading is a feature of certain Pentium 4 chips that makes one physical CPU appear as two logical CPUs. It works by physically duplicating certain sections of the processor (those that store the architectural state), but not duplicating the main execution resources (ALU). It uses additional registers to overlap two instruction streams in order to achieve an approximate 30% gain in performance.

The Control Unit has three main jobs

It controls and monitors the hardware attached to the system to make sure that the commands given to it by the application software are used. For example, if you send something to print, the control unit will make sure the instructions are sent to the printer correctly. 2. It controls the input and output of data so that signals go to the right place at the right time. 3. It controls the flow of data within the CPU.

RAM Random

RAM is in contrast to sequential memory devices such as magnetic tapes, discs and drums, in which the mechanical movement of the storage medium forces the computer to access data in a fixed order. RAM is usually used for primary storage in computers to hold active information such as data and programs

Multi-Processing in the managing programs

More than one CUP running at the same time.

Storage

Storage refers to memory that persists after the computer is turned off (non-volatile). Storage devices include hard drives, flash drives, floppy disks and magnetic tape.

ROM - Read-only memory:

ROM - Read-only memory: In this type of storage, data is pre-recorded and can only be read (e.g., BIOS); it can not be removed. ROM is non-volatile and retained when the computer off.

Managing program

Single-task - Run one program at a time Multi-tasking - Run more than one program at a time Active program (Foreground application) Inactive program (Background application) Multi-threading - do more than one thing at a time (e.g., loading and printing) Multi-processing - more than one CPU running at the same time (e.g., Quad core)

Cache Memory stores the most recent data the CPU has accessed from RAM.

Traffic Cop Translator Recourse Manager

three functions of operating systems

handling input and output, establishing user interface, managing programs