Primary storage and virtual memory
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The teaching part (1 min) is free to watch. A free account opens the whole lecture: 6 practice questions, 2 real past-paper questions with the answers explained, the mistakes that lose marks, the full-marks tip, a one-card summary and a quick quiz.
What this lecture covers
- Why does it slow down?
- Primary storage
- RAM: random access memory
- RAM, up close
Read the transcript of the teaching part
Last time
Before we start: last time, in Input devices, you learned these points. Here they are again on one card. Keep them in mind, because today builds on them.
Why does it slow down?
Open one tab and your laptop is quick. Open thirty and everything crawls. The reason is the computer's main memory. It is fast, but it is small, and it can fill up. In this lesson we meet RAM, ROM, and what happens when memory runs out.
Primary storage
Primary storage is memory that the CPU can access directly. It is fast, but it is relatively small. It is also called main memory, and it is made up of RAM and ROM.
RAM: random access memory
RAM holds the data, programs and parts of the operating system that are in use right now. It can be read from and written to, so its contents change all the time. RAM is volatile, which means all of its data is lost when the power is turned off. Random access means any location can be reached directly, in the same time.
RAM, up close
This is a RAM module. Chips on a small board hold the data. Metal contacts along the edge plug it into the motherboard. More RAM means more programs and data can be held at once.
How often it comes up
The whole chapter: Data Storage.
Chapter 3.3: Primary storage
- Primary storage and virtual memory 6 min
Also for IGCSE Computer Science 0478
Which topics come up most in IGCSE Computer Science 0478 past papers, counted from every paper since 2004: Paper 1 topic frequency, Paper 2 topic frequency.