chapter 5

Question 1

what are the key management tasks of an OS

Answer 1

• provision of a user interface
• provision of a software platform
• memory management
• file management
• security management
• process management
• hardware management
• error checking and recovery

Question 2

how does the os manage memory

Answer 2

• allocates memory to processes and keeps track of memory locations
• manages paging, segmentation, and virtual memory // moves data from secondary storage when needed
• reclaims unused blocks of memory (RAM)
• prevents two programs from occupying the same area of RAM at the same time.

Question 3

a user interface allows…

Answer 3

a user to communicate with the hardware

Question 4

file management

Answer 4

• creates files/folders
• renames files
• controls access

Question 5

security management

Answer 5

• Creates accounts/passwords
• Checks access rights and prevents unauthorized access
• Provides recovery for lost data
• Ensures data privacy
• Provide anti-malware

Question 6

process management

Answer 6

• Decides which process to run next
• Supports multitasking
• Handles priorities

Question 7

utility software

Answer 7

• disk formatter
• virus checker
• disk repair software / disk contents analysis
• back-up software
• disk defragmenter
• file compression

Question 8

virus checker

Answer 8

• Checks for and then removes any viruses found
• Constantly checks all incoming and outgoing files

Question 9

disk formatter

Answer 9

• Prepare a disk for initial use
• checks all sectors and marks bad sectors.
• Makes existing data inaccessible

Question 10

disk repair

Answer 10

• To check for and fix inconsistencies on a disk
• Checks for and marks any errors/bad sectors on the disk
• Resolves any errors on the disk

Question 11

back-up software

Answer 11

• to make a copy of data at regular intervals
• so that if it lost it can be retrieved

Question 12

defragmentation software

Answer 12

• Reorganizes disk contents into contiguous memory sectors
• Improve disk access times // Data/files can be loaded faster
• defragmentation also creates larger contiguous free space regions

Question 13

fragmentation

Answer 13

contents of file scattered across multiple sectors. fragmentation slows down computer performance and speed of file access

Question 14

what is a DLL?

Answer 14

• A shared library file
• Code is saved separately from the main .EXE files
• Code is only loaded into main memory when required at run-time
• The DLL file can be made available to several applications at the same time.

Question 15

features of an IDE

Answer 15

• Context sensitive prompts
• Syntax checking
• Pretty printing
• Single-stepping
• Breakpoints
• report/watch window
• compiler/interpreter

Question 16

context sensitive prompts

Answer 16

Displays a list of keywords or prompts that could be used

Question 17

dynamic syntax checks

Answer 17

errors are underlined by the IDE

Question 18

prettyprinting

Answer 18

involves color coordinated code, indentation, and built-in functions like def(). is used to make the groups of code more identifiable, and easier to code.

Question 19

collapsing code blocks

Answer 19

collapsing massive chunks of code

Question 20

single-stepping

Answer 20

you can execute a single node at a time, causing the program to pause after the node completes

Question 21

breakpoints

Answer 21

The breakpoint ends the program

Question 22

report window

Answer 22

shows how variables change in the program

Question 23

assembler

Answer 23

translates low-level code (assembly language) into machine code

Question 24

compiler benefits

these are also the features

Answer 24

Produces an executable file
User does not have access to source code
It will (probably) be faster to run the executable code
Code does not have to be compiled each time it is run
Does not need the compiler to be present at run-time

Question 25

compiler drawbacls

Answer 25

• Larger amounts of source code take time to compile
• Slower to produce the object code than an interpreter
• Code cannot be changed without recompilation
• The program will not run if there are errors
• One error may result in other false errors being reported
• Cannot test specific sections of code

Question 26

interpreter benefits

Answer 26

• Easier de-bugging because errors can be corrected in real-time. The effect of any change made to the code can be seen immediately
• Parts of the program can be tested, without all the program code being available.
• Reads each line then translates it and executes it
• Stops when an error is encountered // displays errors where it finds them

Question 27

interpreter disadvantages

Answer 27

• has to be present during run-time
• interpreted code runs slower than compiled code (compilers take longer to generate the code not run it) as it needs to be interpreted every time it is run
• no .exe file produced so users have access to source code