Lesson 4 of 6
Doing the work, holding the work, saving the work
One idea at a time. Try the example, then keep going.
Big ideas · 1 of 5
Big ideas
Do this: Read each job. Then explain the difference without looking.
The CPUThe part that carries out the instructions.Exactly: The processor that executes program instructions, using working data held in RAM.Mix-up alert: RAM holds current work. The CPU carries out instructions; RAM does not do the calculations for it.See this in Key words carries out a program's instructions. For example, it follows the instructions to calculate a total. RAM does not do that calculation for it.
RAMWorking space for what the computer is using now.Exactly: Working memory holding data and instructions in use. Ordinary RAM loses its contents when power is off.Mix-up alert: More RAM does not directly add space for saved files in persistent storage.See this in Key words holds the data and instructions being used right now. It is working memory. Ordinary RAM is VolatileLoses its contents without power.Exactly: Describes memory that does not retain its contents when power is removed, such as ordinary RAM.Mix-up alert: This describes RAM, not a saved file in persistent storage.See this in Key words: it loses its contents when power is off.
Persistent storageThe place that keeps saved files when power is off.Exactly: Storage that retains saved data and programs beyond the current powered session. Deletion or damage can still lose files.Mix-up alert: Persistent means retained without power, not impossible to lose. Cloud storage uses persistent storage on computers elsewhere.See this in Key words keeps saved files and programs when power is off. Persistent means it lasts beyond the current session, not that it lasts forever. Deletion or damage can still lose a file.
Seeing an edit on your screen does not prove that edit was saved. Some apps save automatically. Check the save status and reopen the intended file to check the saved copy.
Step-through
Do this: Step through the picture. Name what each part does.
Use the desk and cabinet picture to separate three jobs. Then imagine turning the power off.
Whole picture, 4 steps
4 steps. Tap a number or Show me how it works.
Do this: Read the story. Point out the saved version and the unsaved change.
Nia edits a club poster on a Chromebook. The CPU follows editing instructions using data in RAM. She saves a copy to the Chromebook's storage and checks it. She then adds a star, but this change is not saved anywhere. If the Chromebook shuts down now, for example because the battery runs out, RAM loses its contents. The saved poster remains in storage, but that copy has no star. In an app with autosave, she would check what actually saved before deciding what was lost.
Do this: Say which part keeps a file after power is off.
More RAM gives more working space. It does not replace the CPU or add room to persistent storage. A file in storage can survive power being off. Work held only in RAM cannot.
From other sites
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TED-Ed, about 5 minutes
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Code.org, about 4 minutes
Watch from 0:42 to 2:32
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Start here if it helps: The CPU is responsible for...
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Flashcards
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Think of the worker.
On the card: Enter or Space flips. Left and Right move. After revealing, 1 marks Still learning and 2 marks Know it. Tab reaches every control.
What does the CPU do?
It carries out program instructions, such as calculating a total.
What does RAM hold?
Data and instructions being used right now. It is working memory.
What does persistent storage keep?
Saved files and programs, including when power is off.
What does volatile mean for RAM?
RAM does not keep its contents without power.
Does turning a Chromebook off erase its saved files?
No. Persistent storage keeps saved files without power. That is different from RAM.
Does persistent mean impossible to lose?
No. Files can still be deleted, damaged, or lost with a damaged device.
An edit appears on screen. Is that proof it was saved?
No. Check the save status and the intended saved file. Some apps save automatically.
Does adding RAM give an archive more persistent storage?
No. RAM is working space, not extra space for saved files.
True or false
Do this: Choose True or False. Read each explanation.
Flashcards
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Card 1 of 7
0 Know it0 Still learning
Worker or working space?
On the card: Enter or Space flips. Left and Right move. After revealing, 1 marks Still learning and 2 marks Know it. Tab reaches every control.
Which part carries out instructions to calculate a club total?
The CPU, not RAM.
Where can saved programs remain while power is off?
In persistent storage.
In Nia's example, a star was never saved. Does the saved poster have it after shutdown?
No. The saved poster remains, but it has no star.
How can you check which poster version was saved?
Check the save status, then reopen the intended saved file.
Why should you check save status instead of assuming every recent edit is lost?
Some apps save automatically. Check what actually saved.
What does more RAM give a Chromebook?
More working space, not a replacement CPU or more persistent storage.
Can a saved file be lost even though storage is persistent?
Yes. Deletion or damage can still lose it.
True or false
Do this: Choose True or False and read each explanation.
Self-test
Do this: Answer each question and read the explanation before moving on.
8 questions. One at a time.
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Match
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Connect the ideas
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Classwork
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https://gradebridge-beryl.vercel.app/learn/csc/computer-hardware/cpu-ram-and-storage#classwork
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https://gradebridge-beryl.vercel.app/learn/csc/computer-hardware/cpu-ram-and-storage#homework
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