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Computer Science IGCSEPDF 20
142 pagesrevision 46930
PDF 20
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Input
Output
Process
A mouse is used to click on a file icon.
If the instruction being executed is OPEN, the
system retrieves the file data and prepares it for
viewing.
The contents of the file are displayed on the
screen for the user.
A microprocessor is an integrated circuit that fits onto a single
chip.
It includes the CPU and may also contain additional components
such as:
■ Memory controllers (handle data flow to and from
memory)
■ Input / Output controllers
Central Processing Unit (CPU) is responsible for fetching,
decoding and executing instructions.
Laptops, Desktops and even mobile phones have a CPU.
Theuser uses an input device to enter data and commands. The
CPUprocesses the data by following instructions, and the results
areshown through an output device.
INPUT
PROCESS
OUTPUT
→
→
STEP
● Microprocessor
EXAMPLE