1.2.1 OS Flashcards
What is a multi-tasking operating system
running multiple programs apparently simulatenously
What is a multi-user operating system
Allows more than one user to access a computer’s resources at one time.
what is a distributed operating system
Allows multiple computers to work together as a single system
What is an embedded operating system
Built into a device, oftern with limited resources.
What is a real-time operating system
Guaranteed to carry out actions within a given period of time.
what is a virtual machine?
A program that has the same functioinality as a physical machine.
Why would you use a cirtual machine to run different operating systems.
- A program could be OS specific
- you may be developing an app for different platforms(OS)
What is itermediate code
it is a compromise between compiled and interpreted programs. It is an efficient representation of the source code.
What are the advantages of intermediate code with virtual machines
- any device with the virual machine software can run the program
- Programs are very portable between system types.
- source code not visable
What is the functions of an operating system?
- Manage hardware
- Manage programs being installed and run,
- manage the security of the system
- provide an interface between the user and the computer
State functions of an OS.
- memory management
- provide a user interface
- manage hardware/peripherals
- manage CPUI usage / handles interrupts
- providing secuirty
- provide platform to run other software
- provide utilities for system maintenance.
State the name of the type of memory management used to diuvide memory into equally sized chunks.
Paging
Describe how the operating system would use virtual memory to load program C.
- Os uses area of secondary storage as virtual memory
- move unused pages / parts of other applications into virtual memory.
- loads program C into (physical) memory.
Explain why using a risc processor rather than a cisc processor is likely to result in increased battery life.
- RISC has a smaller instruction set than CISC.
- RISC has less tranisters than CISC
- means less power is reqiured.
define the term embedded opperating system
system software/ software used to manage the device,
which is built into the device itself
stored in the device’s ROM
specific to the hardware / purpose
What is the kernel and what is its purpose.
Ther kernal is the core of the OS,
- managing system resources
- scheduling processor time
- sending/receivig data from device
What does memory management ensure?
- adequate RAM is allocated
- That programs do no interfere with each other’s use of memory
- Program sharing of RAM is controlled for secuity reasons
- memory is used efficiently.
What is segmentation
The splitting of a program into logical coponents
What is paging
splitting a program into blocks of the same size
What is virtual memory
The use if secondary storage as an extension of the computers physical memory.
What is a scheduler?
A program that manages the amount of time different processes have in the CPU.
Name the 5 scheduling algorithms
- round robin
- First come first served
- shortest job first
- shortest remaining time
- multi-level feedvack queues.
What is an interrupt
Different devices and processes may need the processors attention at various times, they signal the processor for attention via an interrupt.
What data structure is used while interrupts are being serviced
A stack
What is the purpose of BIOs
- check hardware components are functioning
- When complete a boot leader begins to load the operating system into memory.
