Chapter 4 Software: Unit 4.1: Types of Software and Interrupts Part 2 Flashcards
What are the functions of the operating system?
Human computer interface (HCI)
Multitasking
Platform for running application software
Management of user accounts
Managing files
Hardware peripheral management (including drivers)
Memory management
Interrupt handling routines
Security
Define CLI
Command Line Interface
Requires a user to type in instructions in order to choose options from menus, open software, etc.
There are often a number of commands that need to be typed in, therefore the user has to learn a number of commands just to carry out basic operations, which makes operations slow as the user has to manually type the commands in every time an operation has to be carried out.
The advantage of CLI is that the user is in direct communication with the computer and is not restricted to a number of pre determined options.
Define GUI
Graphical User Interface
Allows the user to interact with a computer using pictures or symbols (icons) rather than having to type in a number of commands.
Simply selecting any of the icons from the screen would automatically load the app into the phone ready to be used.
GUIs use various technologies and devices to provide the user interface.
One of the most common is WIMP (windows icons menu and pointing device), which was developed for use on PCs.
What are the advantages of CLI?
The user is in direct communication with the computer
The user is not restricted to a number of pre-determined options
It is possible to alter computer configuration settings
Uses a small amount of computer memory
What are the disadvantages of CLI?
The user needs to learn a number of commands to carry out basic
operations
All commands need to be typed in which takes time and can be error prone
Each command must be typed in using the correct format, spelling, and so on
What are the advantages of GUI?
The user doesn’t need to learn any commands
It is more user-friendly; icons are used to represent applications
A pointing device (such as a mouse) is used to click on an icon to launch the app – simpler than typing in commands
What are the disadvantages of GUI?
Uses up more computer memory than a CLI interface
The user is limited to the icons provided on the screen
Needs an operating system
What are the functions of the memory management?
Manages the primary storage (RAM) and allows data to be moved between RAM and HDD/SSD during the execution of programs
- keeps track of all the memory locations
- carries out memory protection to ensure that two competing applications cannot use the same memory locations at the same time. If this wasn’t done the following might happen:
– data would probably be lost
– applications could produce incorrect results
– potential security issues
– in extreme cases, the computer could crash
What is the function of the security management?
Ensures the integrity, confidentiality and availability of data.
This can be achieved as follows:
- carrying out operating system updates as and when they become available
- ensuring that anti virus and other security software is always up to date
- communicating with, for example, a firewall to check all traffic to and from the computer
- making use of privileges to prevent users entering ‘private areas’ on a computer that permits multi-user activity
- maintaining access rights for all users
- offering the ability for the recovery of data (and system restore) when it has been lost or corrupted
- helping to prevent illegal intrusion into the computer system
What is the function of the hardware peripheral management?
Hardware management involves all input and output peripheral devices.
Hardware management:
- communicates with all input and output devices using device drivers
- uses a device driver to take data from a file and translates it into a format that the input/output device can understand
- ensures each hardware resource has a priority so that they can be used and released as required
- manages input/output devices by controlling queues and buffers
What are the main tasks of the file management?
The main tasks of file management include:
- file naming conventions which can be used
- performing specific tasks
- maintaining the directory structures
- ensuring access control mechanisms are maintained
- ensuring memory allocation for a file by reading it from the HDD/SSD and loading it into memory
What is the function of multitasking?
Multitasking allows computers to carry out more than one task at
a time, which will each share the hardware resources under the control of the operating system software.
To make sure that multitasking operates correctly, the operating system needs to constantly monitor the status of each of the processes under its control.
- resources are allocated to a process for a specific time limit
- the process can be interrupted while it is running
- the process is given a priority so it can have resources according to its priority
Using multitasking management, main memory, HDD/SSD and virtual memory are better managed making the most effective use of CPU time.
Describe the process of the running of applications.
The application software will be under the control of the operating system and will need to access system software such as the device drivers while it is running.
Different parts of the operating system may need to be loaded in and out of RAM as the software runs.
Describe the process that a computer takes while starting up.
When a computer starts up, part of the operating system needs to be loaded into RAM – this is known as booting up the computer (or a bootstrap loader).
The start-up of the computer’s motherboard is handled by the BIOS, which tells the computer where the storage device that holds the operating system can be found; it then loads the part of the operating system that is needed and executes it.
The BIOS program is stored in a special type of ROM, called an EEPROM. EEPROM is a flash memory chip, which means its contents remain even when the computer is powered down. However, it also means the BIOS can be rewritten, updated or even deleted by a user.
However, while the BIOS is stored on an EEPROM, the BIOS settings are stored on a CMOS chip.
The CMOS is powered up at all times via a rechargeable battery on the motherboard.
Once the CMOS is restarted, it will access the same BIOS
program from EEPROM, but the settings will now be the default factory settings.
Define interrupt
Signal sent from a device or from software to the microprocessor. This will cause the microprocessor to temporarily stop what it is
doing so that it can service the interrupt.
Interrupts allow computers to carry out many tasks or to have several windows open at the same time.
