5 - Operating Systems Flashcards
(27 cards)
What are the three types of application software?
General purpose / off the shelf
Bespoke
Special purpose
What is general purpose software?
Standardised software available to the general public e.g. Microsoft word
What is bespoke software?
Custom software which is made specifically for the client e.g. eBay’s website
What is special purpose software?
Special purpose software is a software written for a singular task
Name four types of utility software
Virus scanner
Disk defragmenter
System monitor
File manegement
What do virus scanners do?
Scans the computer for potential viruses, by checking for malicious code. Updates weekly to check for new types of malicious code.
Explain how disk defragmenters work
When data is stored on a hard drive the programs often get broken up.
This means it will take longer to read each program as the hard drive has to constantly jump around. To stop this disk defrag places all the parts of a program next to each other.
What does a system monitor do?
Monitors the computers performance and system resources
What is file magement
Creates an organised system of files allowing data to be accessed easily
Advantages of bespoke software
Can be customised to specific needs
Code can be altered upon request
Disadvantages of bespoke software
Expensive.
No online support or guides.
Doesn’t receive constant updates.
Long wait time while being developed.
Software companies make code complicated so clients can’t go to other companies.
Companies go out of business so source code may not be accessible.
What is the operating system
A set of programs that manage the computer hardware to hide the complexities from the user.
What tasks does the operating system manage?
File management
Processor management
Peripheral management
Battery management
Name the two methods of process management
Round robin
Scheduling
What is scheduling?
Assigning a priority ranking and allocating higher priority tasks more processing time
What is round robin CPU allocation
Each task is allocated an even amount of processing time
Benefits of scheduling over round robin
High priority tasks are completed quickly
Benefits of round robin over scheduling
Lower priority tasks are still executed as they are assigned the same amount of processing time
Explain virtual memory
- Space in the hard drive is used as extra storage for currently open programs.
- The physical memory is split into fixed size pages so the RAM can easily find the data
Advantages and disadvantages of virtual memory
Allows the computer to continue running even when the RAM is full.
However this process is very slow.
What are library programs
Collections of routines which are shared by multiple programs. This is why all Microsoft office programs look the same: because they all use the same libraries.
What is a DLL
Dynamic Link Libraries are collections of small programs that larger programs can load. E.g. communicating with the printer
Advantages of libraries
- Allows sharing of code across platforms.
- Saves memory as routines are only loaded when needed
- Reduces the time taken to write programs
What is the key disadvantage of DLLs?
Some programs may alter DLLs without authorisation which may corrupt them.
