Fundamentals of computer
systems
Last edited time @October 1, 2023 9:37 AM
Status Done
Hardware and Software
Hardware → The physical parts of a computer, both internal and external.
It can be broken up into subsections:
External components (peripherals) → Referred to as input/output devices
(I/O devices). Mouse, Keyboard, printer etc.
Internal components (processing and storage) → processor, hard disk,
GPU etc.
Software
Software → any program that can run on a computer.
There are 2 main types of software:
Application software → programs that perform specific tasks that would need
doing even if computers didn’t exist. e.g editing text with programs such as
Word
System software → Software that is concerned with the running of the
computer itself. It for the management of the computer and not the tasks it
can complete.
Utility programs → programs that perform useful tasks that relate to the
running of the computer. They are usually supplied with the operating
system. Examples include compression software, disk clean-up and anti-
virus software.
Library programs → code, data and resources that called and used by
other programs. These tend to be essential for a computer to function.
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, Examples include managing memory, displaying text and graphics and
controlling dialog boxes.
Translators: compilers, assemblers and interpreters → programs that
convert programming language instructions into machine code (binary).
Operating system software → Software that acts as an interface between
the user and computer. It manages the overall operation of the computer.
It creates the virtual machine.
Virtual machine → the concept that all of the complexities of using a
computer are hidden from the user and other software by the
operating system.
The software is generally very large (1GB of ram, 16GB of hard drive) as
it performs lots of tasks, for example:
controls start-up configuration
sends signals to different controllers such as the hard disk controller.
recognises button presses and then processes them.
allocates memory
copes with errors
controls print queues.
Manages the users on a network.
Resource management
Processor → A device that carries out the computation on data by following
instruction, in order to produce an output.
The processor uses scheduling to give the illusion of multi-tasking. It does this
by alternating between different processes very rapidly. There are different
scheduling such as ‘round robin’ which allocates the same set amount of time
to each task and runs through each one. There is also dynamic scheduling
where the processor switches to a different task, if an application is idle.
Managing input/output devices
These connect to the processor and provide data to it. In order from them to
connect to the processor, the computer uses drivers which are special
program that allow the device to communicate with the processor and
computer.
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