Topic 4 - Computer Systems (key points of spec) Flashcards
4.1 - Define the terms hardware and software and understand the relationship between them.
Hardware is the physical component of a computer. Software is the programs that run on a computer.
A relationship between them is that a computer system can’t function without software AND hardware.
4.3 - Explain what is meant by: system software, application software
System software is any software that assists with the running or management of the computer system. Application software is any software added to the system that enables the user to perform a task.
4.3 - Give examples of both types of software.
System software:
game engines, utility programs, encryption, backup
Application software:
word processors, internet browsers, games
4.3 - What does the operating system handle the management of?
processors, memory, i/o devices, applications, security
4.3 - What is the need for operating systems and utility programs?
Operating systems control computer hardware and act as an interface with application programs. Utility software helps to manage, maintain and control computer resources.
4.4 - Explain the von Neumann architecture
Von Neumann architecture is the design upon which many general purpose computers are based
4.4 - Explain the role and operations of main memory and the following major components of a central processing unit (CPU)
Memory is the area where the computer stores or remembers data. Memory provides the CPU with its instructions
4.4 - Explain the role and operations of the Arithmetic Logic Unit
Performs two sets of operations on data. Arithmetic operations (+-), logical operations (is A>B?)
4.4 - Explain the role and operations of the Control Unit
control unit coordinates and controls all of the activities taking place within the CPU. it decodes instructions and executes them. also receives signals from the system clock
4.4 - Explain the role and operations of the Clock
controls the timing of the processor, synchronizes all CPU operations
4.4 - Explain the role and operations of the bus
collection of wires through which data is transmitted from one component to another. used to send control signals and data between the processor and other components
4.4 - Explain the effect of the clock speed on the performance of the CPU.
higher clock speed determines how many cycles the CPU can deal with in a second
4.4 - Explain the effect of the number of processor cores on the performance of the CPU.
multiple cores will give the CPU more power to run multiple programs at once but some of the extra speed will get used up as the cores have to communicate with each other through channels.
4.4 - Explain the effect of the cache size on the performance of the CPU.
the bigger its cache, the less time a processor has to wait for instructions to be fetched.
4.4 - Explain the effect of the cache type on the performance of the CPU.
the higher the memory size, the more powerful the cache size.
4.4 - Understand the fetch-execute cycle.
fetch: the next instruction is fetched to the CPU from main memory.
decode: the instruction is decoded to work out what it is
execute: the instruction is executed.
4.4 - Understand the differences between Main memory and secondary storage.
Main memory:
volatile, fast to read/write, directly accessible by the CPU.
Secondary Storage:
non-volatile, slow to read/write, not directly accessible by CPU.
4.4 - Understand the differences between RAM and ROM
ROM can be read not written, helps boot up the computer, used a lot in embedded systems such as dishwashers, microwaves, etc
RAM can be read and written, it is volatile and used to store running programs and operating systems.
4.4 - Understand why Secondary Storage is required.
Secondary storage is needed to keep programs and data. Without it, all programs and data would be lost the moment the computer is switched off.
4.4 - Explain the operations of solid-state storage
Data is recorded onto solid memory chips without any moving parts. SSD’s use electrical circuits to store data.
4.4 - Explain the operations of magnetic storage.
mechanical parts move over disks surface to read and write data magnetically.
4.4 - Explain the operations of optical storage
lasers read and write data using light.
4.4 - list advantages and disadvantages of magnetic storage
advantages:
cheap, large storage capacities, fast write speed
disadvantages:
lots of mechanical parts, durability is an issue
4.4 - list advantages and disadvantages of optical storage.
advantages:
cheap, portable, takes up little space physically
disadvantages:
less storage capacity, easily damaged, slow write speeds.
