Computer Systems

Programs that the computer system runs

The physical components that make up the computer

system software manages the computer system resources and acts as a platform to run application software

application software is software that performs end-user tasks

A collection of programs that manage and control the computer. Connects the hardware with the software

• oranising the CPU and it’s processing tasks • memory managment and allocation • communicating with input/output (I/O) devices • providing a platform for applications to run on • managing security security and user accounts

It allocates the times each program has with the CPU, it allows multi tasking

Paging - allocation of memory, what goes in the RAM or secondary storage

Allows instructions to be exchanged within peripherals (input output devices) , the have different languages.

Individual users can be created and deleted, Access levels to users Passwords and usernames

Helps to maintain the systems Utility programs help maintain or configure a computer

🟣encryption (security) 🟣defragmentation 🟣virus scanner 🟣back ups 🟣compression

Takes fragmented files in the hard drives and puts them together, so that when the file is needed time won’t be wasted finding it. (Decreases time read/write head spends moving back and forth across the disk))

Made to high capacity secondary storage devices or the cloud, in case data is lost to hacker

It fetches , decides and executes instructions Controls hardware and moves data around the computer

The arithmetic logic unit does arithmetic and logical calculations

Small amounts of High speed memory contained within the CPU. PC MAR MDR CIR

Small amount of high speed RAM. Temporarily holds data and instructions that the processor is likely to reuse

Co- ordinates all of the computer components by sending out regular electrical pulses which synchronises all the components. The frequency is known as the clock speed

Data and instructions are stored together and have memory addresses

The more pulses per second , the more FED cycles can be performed. This could lead to over heating tho

The larger the chance is , the less time a processor has to wait for instructions to be fetched

Then more instructions can process in a given space of time, but some instructions rely on the previous so is not proportional to speed.

🟣the CU reads the memory address of the next instruction 🟣this instruction is copied to the registers 🟣the address is incremented by 1 🟣the instruction is decoded by the CU 🟣the instruction is performed Eg: ALU performing a calculation, data being stored into memory