Unit
1.1 Information processing cycle Remember:
You can also store
Communication
information using
external storage
devices (for example
Input Processing Output
USB drives or external
hard drives).
Storage
Figure 1.1: The stages of the information processing cycle
INPUT
Definition: In the input stage, the data is entered into the computer.
Just to refresh your memory, input devices are things such as keyboards, touchscreens and
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microphones.
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The user inputs the data (for example, by typing on a keyboard or speaking into a
microphone) into the computer.
PROCESSING
Definition: The central processing unit (CPU) inside the computer then takes that binary code and
does the calculations needed to get that data to display in a way that makes sense to the user.
•s
The CPU works with the computer’s memory to get instructions on how to display the
information from the input device and stores it as pixels in the computer’s memory. This
information is sent to the output device to be translated and displayed in a way that is useful.
STORAGE
Definition: Storage is where the computer takes the input and stores it in its memory banks.
@
There are many ways to store the data, 1. The CPU writes the data to the computer’s temporary
Storage, or random access memory (RAM). 2. The computer then waits for the user’s command to
move the data from the RAM to more permanent storage. If that command is given, the computer
writes the data to the disk drive. 3. Lastly, the computer saves the data in a location on the drive,
either the default storage location or a location set by the user. The user can then recall this stored
information at any time.
1 I
, OUTPUT
Definition:Output is where the computer takes the pixels from the processing stage and displays
them in a way that the user can see them.
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There are many kinds of output devices, such as printers, screens, video and audio devices.
These devices make the raw data usable and visible, allowing human users to interpret the data,
turning it into information. This could be the sound waves of a song or the letters in a document.
COMMUNICATION
•
Communication is linked to the other stages in the information processing cycle.
Each part of the cycle happens because one of the other steps came before it, meaning that they
are linked. This link is the communication aspect of the information processing cycle.
The most visible aspect of this is the relationship between input and output. Input and output
happen almost immediately (for example typing a letter on a keyboard makes it appear almost
immediately on a screen).
This is communication between the user and the computer.
Activity 1.1 UNIT: 1.2 Computer features and classification
&
Computers can be broadly separated into three categories, namely: 1. Non-portable: server,
desktop. 2. Portable: laptop, tablets, smartphones. 3. Dedicated devices: ATM, smart fridge.
Computer classifications
Devices Uses Processing power Portability Image
Their primary purpose is They are designed to process Not at all portable, since they
Server to serve information to massive amounts of data quickly, are connected to each other
users. They usually focus so have an extremely high in a network. Removing one
on one type of means that it no longer
processing power.
information. functions as a server.
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General office and household They can be extremely powerful, Not very portable, since they are
Desktop PCs use, including gaming, photo especially those designed for heavy
large and heavy. The internal
components can be quite
and video editing, budgeting use. In general, the processing power
delicate and the PC will need
and web browsing. ranges from medium to very high. an external power source.
They are referred to as mid-range These devices are portable. They
Laptops/ devices, meaning that they are contain a battery, so do not
Generally used for office always need an external power
notebooks work or personal use.
suitable for normal use source. Most are lightweight
(document creation and editing, with some, such as the Asus
(portable devices) web browsing, etc.). Zenbook, being extremely light.
Tablets are also portable as they
Their processing power is not are designed to be mobile.
Tablets (portable Mainly used for
Tablets play an important role in
entertainment or web very high.
devices) browsing.
the rise of mobile computing,
which is the idea that you can
take your computer anywhere.
Designed mainly as a They are not designed to be high- Smartphones are extremely
Smartphones communication device and powered computing devices, portable since they are a blend
(portable devices) come with pre- installed although some do have quite a lot of of ultra-portable computing
messaging and voice-call apps. processing power. devices and mobile technology.
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