Section 2 - Systems Software Flashcards
What is an operating system?
An operating system is a program or set of programs that manages the operations of the computer for the user.
What is the Operating Systems job?
The operating systems job is to act as a bridge between the user and the computer’s hardware.
What is the loader?
The loader is a small program held in the ROM, when a computer is switched on, the loader in the ROM sends instructions to load the Operating system by copying it from storage into RAM
What functions is the operating system responsible for?
Memory management, Interrupt service routines, Processor Scheduling, backing store management, management of all inputs and outputs.
What does “Memory management” mean for the operating system?
Memory management means that multiple applications need to be able to be run in tandem, where the Operating System is responsible for the allocation and management of space which these applications take up.
What is an Interrupt?
An interrupt is a signal from a software program, hardware device or internal clock to the CPU. and they are split up into software interrupts and hardware interrupts.
What is a Software Interrupt?
A Software Interrupt is an interrupt that occurs when an application program terminates or requests certain services from the operating system.
What is a Hardware Interrupt?
A Hardware Interrupt may occur when an I/O operation is complete or an error involving the hardware of a computer occurs.
What is another reason for Interrupts occuring?
Interrupts also occur regularly and are triggered by a timer, this is used to indicate that it is the turn of the next process to have processor time, and because of this, multi-tasking can occur.
What is an Interrupt Service Routine?
The Interrupt Service Routine is the process that occurs whenever an interrupt is called, with each classification of interruption leading to a different routine being run to service it, depending on the priority of the interrupt, such as a Power-fail interrupt being given the highest priority, followed by a clock interrupt and then an I/O device sending a signal.
