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Computing Revision
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GCSE - Full Content
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, Explain the terms hardware and software ● Hardware are the physical aspects of a computer
system that can be touched
● Software are programs, written to run on a
computer system, includes programs that can
control and use the hardware.
● Hardware is the physical components of a system
whereas software is code that runs on the
hardware
Types of software ● Application software
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○ Application software enables the user to
carry out productive tasks
○ E.g web browser, word processor, video
editing, spreadsheet
● System software
○ Set of computer programs that are
designed to manage the computer
system
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○ Includes the OS and utility software
○ The OS is essential for the hardware to
run and for the user to interact with the
system
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Operating systems ● Operating system is the software that is used to
manage the hardware within a computer system
● Examples include e.g microsoft windows, Mac OS,
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●
android
Operating system is a link between the hardware
and the software
Functions of an operating system include:
○ Managing the human-computer
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interface
○ Moving data to and from secondary
storage and file management
○ Sharing memory between software
○ Scheduling the processor and
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multitasking of software
Utility programs ● Utilities are software tools that complement the
operating system in managing the smooth running
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of the computer system
○ Encryption
■ Software scrambles a file so
that if it is accessed by an
unauthorised user it can't be
understood
○ Anti-spam
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■ Software attempts to reduce
the amount of unwanted
emails received by an email
client
○ Backup
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■ Utilities make automatic
backups of files and disks
○ Defragmentation
■ Utilities reorganise the data
stored on a disk so that large
data files and program files
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are kept together rather than
spread out across a data
■ Speeds up data access
speeds
○ File compression
■ Utilities make files smaller in
size so that more can be fitted
onto a storage medium or to
make data transmission
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, ● Describe two different functions performed by an
operating system.
○ Memory management
■ Manages the computer's
memory
■ Schedules which processes
are to be executed
○ Processor management
■ Manage the computer's
processors (CPU)
■ Schedules which processes
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are to be executed
○ Managing storage
■ Manage secondary storage
devices
■ Loading data and programs
into the computer's memory
■ Storage space management
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Explain the ‘Von Neumann architecture’ ● Identified that data and programs could be stored
in the same memory
● Means only one set of RAM is required for storing
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both data and programs
● Don't need two separate sets of memory
Explain the role and operation of main memory and the ● ALU
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(CPU):
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arithmetic logic unit
control unit
clock
● CU
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Carries out arithmetic ( +, -, *,/)
Logical operations (AND, OR, NOT)
Manages the execution of instructions
Makes sure that all the components
perform their tasks at the correct time
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○ FDE Cycle
• bus ● Clock
○ Signal that synchronises tasks
○ Clock cycle
○ Each tick of clock CPU processes one
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or more instructions
○ More clock speed more faster
instructions processed
● Bus
○ The CPU includes system bus
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○ Set of wires connecting (CPU,Memory,
I/O)
○ Data bus (instructions and data items)
○ Control bus (control signals)
○ Address (memory addresses)
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Explain the effect of the following on the performance of
the CPU:
● Clock speed
• clock speed
○ Number of clock cycles per second
• number of processor cores ○ More times a second the clock ticks,
• cache size more instructions carried per second
○ Overclocking (cause overheat and some
• cache type processes not being completed before
next instruction is started)
● Number of processor cores
○ A core is the processing unit which
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