• Learning objectives

Operating system

Define "Operating system"

• An operating system (OS) is a piece of system software which controls the hardware within a computer
• State the 4 functions of a operating system and explain further [4 marks]

Interrupts

• A signal sent from software/hardware to the processor
• When will Interrupts appear? (e.g.)

Buffers

Buffers are used in computers as a temporary memory area.

Example of use of Buffers:

• Buffers are essentially filled form the processor/memory unit and whilst these are emptied to the hardware device, the processor carries on with other tasks.

Applying the knowledge:

Describe the use of Interrupts and buffers in printers.

The interrupt is sent from the device to the printer’s processor to stop what it's doing and print the document, meanwhile, the data is sent to an area of memory called an buffer, while the buffer feeds the CPU, the printer prints the document, and once its finished printing, another interrupt is sent from the printer to the device, to let the device know its done printing and is ready to receive more data as the buffer is emptied.