Science and Elementary Technology

Introduction

Introduction
A computer is an important device. It can store data in its internal memory.
Since a computer can store information it is a very important friend that you need in your life.

Look at the following pictures.

Describe each picture above.
Predict what you are going to learn.

4.1: Data and memory

Activity 4.1: Finding out what data is

Explain the meaning of data.

Meaning of data
Data are facts and figures that need to be processed by a computer.
Processed figures and facts are called information.
Example of data include:
• Letters of the alphabet, for example A, B,
C, D etc.
• Numeric numbers such as 0, 1, 2, 3 etc
• Symbols like *, $, %, –, = etc

The data is entered into the computer using computer input devices like the keyboard and mouse.

Meaning of memory

Activity 4.2: using memory

(i) Write down the name of your school.
(ii) Write down the name of the teacher who taught you in P1.
How were you able to remember your P1 teacher?

Memory refers to parts of the computer that are used to store data or information.

Roles of memory

Activity 4.3: Typing in the Write Activity

(i) Start the Write Activity from the Home View.
(ii) Type the following in turns:
• Name of your district              • Your name
• Name of your school              • Name of your class teacher
(iii) Where is the information that you have typed stored?
(iv) Now save the information that has been stored on a flash disk.

For a computer to store information effectively, it should have memory. Memory holds instructions and data needed to complete tasks.

4.2: Examples of data and memories

Internal storages

Activity 4.4: Storing data in memory

(i) Start Write Activity.
(ii) Type the following:
• Name of your school
• Name of your class
• Your name
(iii) Close the document and check if the file is available in the journal.

The Journal is the internal storage of the XO laptop. These are the storage/ memory found inside the computer.

There are two types of memories in the computer. 

These are:
(a) The computer memory (RAM/ ROM). (b) Hard disk.

Hard disk

Activity 4.5: Accessing a saved document in the journal

(i) Click on the Journal icon at the bottom of your XO laptop.

(ii) Open the document that you typed in Activity 4.3 by clicking on it.

• The hard disk is a storage device found inside all computers.
• A hard disk is mostly used to store computer programs.
• The hard disk has a large memory space.
The Write Activity automatically saves your work to the Journal. The Journal space is in the hard
disk.

Activity 4.6: Saving documents

(i) After creating a document, click on the Keep button. What do you observe?
(ii) Find the new Journal entry created.
(iii) Go to the list that shows items in the Journal. Give the activity you have saved a different name.

Documents are normally saved in the ODT file format. ODT is Open Document Format.
There are times when you may prefer to save your document in another format, other than the ODT format. To do this, use the Keep button.
The Keep button lets you save a copy of your document in rich text (RTF), hypertext (HTML) or plain text (TXT) formats in the Journal.

ROM and RAM

ROM

Activity 4.7: Boot-up process

(i) Switch on the laptop by pressing the power button. Observe what happens from the time the laptop is switched on until the Sugar Home View is displayed.
(ii) Write down your observations in your notebooks. Share your findings with the rest of the class.

ROM stands for Read Only Memory. It only allows reading of its content. The user cannot change content on it. 

This type of memory is a permanent storage. When power goes off, data written on it is not lost.
This memory is therefore called non-volatile.
ROM contains data that is used when starting computer, checking the RAM and when loading other computer programs.

RAM
RAM stands for Random Access Memory. It is a temporary memory.
Most computers do not store what you have worked on automatically. When power goes off suddenly, what you have been working on disappears.
This happens because data is stored on this memory temporarily and when power is on.
This memory is said to be volatile.

Role of temporary memory

Activity 4.8: Drawing a picture and writing a story

(a) Drawing a picture in Paint Activity
(i) Open the Paint Activity.
(ii) Click on the brush tool then colour-picker tool to set the drawing colour you wish to use.
(iii) Draw a shape of your own choice.
(iv) Fill your picture with your favourite colour.
(v) Use the secondary toolbar to insert below your picture a comment reading: I love drawing.

(b) Writing a short story in the Write Activity
(i) Switch from the Paint Activity to the Write Activity. [The frame key lets you switch between activities.]

(ii) Type the following story exactly as it appears.

My Best Friend
My best friend is Marie. Marie is a beautiful girl. She is very hard working as well.
Marie lives with her grandparents in Mayange Village. Her parents own a shop in Kigali City. They sell groceries.
This holiday, Marie will visit my home together with her parents. I will prepare them my favourite dish.

(iii) Click on the frame key then switch back to the paint Activity.
(iv) Bold the comment you made. Also apply a different font type and font size.
(v) Complete this story by writing more about Marie e.g. the school she goes to, her favourite dish, her best subjects, her hobbies among other things.
(vi) Check how the Write Activity and the Paint Activity have been saved in the Journal.
Why did the Paint Activity remain when you switched to the Write Activity?

The RAM stores instructions and data needed to complete a task or tasks being worked on fast.
The temporary memory also enables computer users to switch between several activities.

External storage

Activity 4.9: Copying a file to the memory card

(i) Start the write Activity and access the Journal. Locate the story that you wrote in Activity 4.8.
(ii) Insert a memory card in the USB slot on your computer.
(iii) Select the journal entry of the story by clicking on it.
(iv) Move your entry to where your storage device icon appears (right side of the journal).
(v) Check to see if your file appears on your storage device.

External storage refers to devices that are not permanently fixed on or in a computer. These devices are used to store information permanently.

These devices include, Memory cards, Flash disks, CDs, DVDs and external hard drives.

(a) Memory card
A memory card is also known as an SD card or flash card. It is an electronic device used for storing digital information.

(b) Flash disk

Activity 4.10: Copying a file/document to the flash disk

(i) Access the Write Activity in the journal.
(ii) Insert your flash disk in the USB slot. Ensure that your computer shows the icon representing the presence of an external storage.
(iii) Drag the Journal entry story that you wrote in Activity 4.8 into the USB icon.
(iv) Outline the importance of saving information on a flash disk.

A flash disk is also known as USB flash drive.
It is connected to the XO laptop through a USB port. Data can be easily saved on it and easily deleted from it.

Activity 4.11: Opening a document stored on external storages

(i) Access the Journal from the Home view.
(ii) Insert in the USB slot a flash disk or Memory card on which you saved the story in Activity 4.8.
(iii) Click on the USB icon that shows on your computer. Open the story in Activity 4.8 by clicking its icon.
(iv) Edit the document by Bolding and Underlining the heading. Format text in your story by changing the font colour, font size and font type.
(v) Close external storage and quit the Journal.

(c) CD, DVD
CD in full means Compact Disk.
DVD in full means Digital Video Disk.
CD and DVDs are inserted in a CD Reader in order to access stored information.

The information on the CD-R is read only. This means that you cannot add more data on a CD or DVD that already has data on it.
Information on CD-RW is read and write.

(d) External Hard disk

It is also known as external hard drive. It is a portable storage device. It has a very large storage space that is similar to that found on the hard disks of computers.

This storage device is connected onto the computer by a cable.

4.3: Sharing a document

The XO laptop allows for connectivity between it and neighbouring XO laptops. This is called collaboration.
Collaboration allows you to share what you are doing with others. You can also see what friends in your neighbourhood are doing.

You can collaborate with others by sending an invitation or by sharing with the Neighbourhood.

(a) Send an invitation

Activity 4.12: Sending an invitation

(i) Create the following story about the environment.

(ii) Go to the Neighborhood View to share your story. Click a friend’s XO icon on your computer to send an invitation request.

(iii) Once you have invited your friend, tell him or her to click the Write icon in the Frame of his or her XO laptop. Let him or her select the Join option from the dropdown menu that appears.

The Write icon has the colour of your Sugar XO icon. Once she or he clicks on the Join Option, he or she can view your story and contribute to it accordingly.

You send invitations to a specific person. When you invite your friends, you allow them to collaborate with you in the Activity that you are doing.
What happens when your friends make changes to the document that you stored?

(b) Share with the neighbourhood

The neighbourhood view in all XO laptops shows all the connected laptops around you. It also shows all the shared Activities.

Activity 4.13: Sharing Activities with the neighbourhood

(i) Access the Neighbourhood view by clicking the Neighbourhood icon on the frame of your computer. You can also use the Neighbourhood icon on your XO screen.

(ii) Find your friends and activities you are interested in by searching for them in the search menu.

(iii) You can join in an Activity you are interested in by clicking on the Shared Activity’s icon.
(iv) Add other users in your Neighborhood to your Friend/ Group by clicking on their XO icons. You can also invite them to share in your Activity.

Additional Activity

(i) Send an invitation to two of your friends to collaborate and continue the story you typed in Activity 4.8 (b) (ii).
(ii) Locate a group in your Neighbourhood. View how they are working on the story you wrote in Activity 4.12. Join them in this Activity.

Revision Activity 4

1. (a) Name the following types of memories.

(b) Identify internal and external memories from the examples above.

(c) Compare RAM and ROM.

2. The following statements refer to RAM. Which one does not?
A. Kind of memory where your computer holds copies of programs and data.
B. Computer uses RAM to store software programs currently in use.
C. Programs are loaded into memory and removed from memory when files are closed.
D. RAM is the same as hard disc.
3. What happens when you first turn on your computer?
A. The Hard Disc takes control
B. The ROM loads the operating system
C. The Gnome desktop appears immediately
D. RAM takes control

4. To send an invitation, you will do the following except one. Which one is it?
A. Open a document
B. Go to Neighborhood View
C. Click a friend’s XO icon to send an invite request
D. Navigate to the tool bar

5. Give three examples of data.
6. Explain what happens when the computer is turned on.
7. Give a reason why the hard disc is an important storage device.
8. List three tasks performed by ROM.
9. Give 2 reasons why RAM is called temporary storage.

10. You have been given a flash disk by the teacher to transfer some pictures from your computer    to the flash disk.
    (a) Insert the flash disk in the XO USB port.
    (b) Access the flash disk and save one file from your XO in it.
    (c) Close the flash disk and eject it from your laptop.
11  (a) Write 3 sentences about your school.
      (b) Share your activity with two friends in your neighbourhood to make a nine sentence                           document.

Word list

1. Read the following words in pairs.
• Retrieved                    • Data                 • Volatile
• Temporary Memory    • Bits                  • Bytes
• Storage Devices         • RAM                • ROM
• Neighbourhood           • Invitation         • Collaborate
• Non-Volatile
2. Spell 3 words while your friend writes them in his or her notebook. Let your friend also spell 3           other words as you write them in your notebook.
3. Discuss with your friend the meaning of any 3 words in the word list. Refer to notes in your               textbook.