y7-Computer systems-Lesson 2

computing systems

Lesson 2: Under The Hood

Move 1: write X in top left-hand corner
wait for the other player to write O in a square
Move 2: IF the bottom right-hand square is empty THEN

  write X in the bottom right-hand square
ELSE
write X in the bottom left-hand square
wait for the other player to write O in a square
Move 3-4: REPEAT 2 TIMES
IF there is a line with 2 Xs and an empty square
THEN write X in the empty square (win)
terminate
ELSE IF there is a line with 2 Os and an empty
square, write O in the empty square (block opponent)
wait for the other player to write O in a square
Move 5: write X in the remaining available square

​Instructions:

intelligent moves

Multiple Choice

What is the main task of a general purpose computing system?

• The main task is to execute instructions.

• It can perform any task prescribed by programs.

• It depends on the system. Different systems may perform a different main task.

• The main task depends on the user. Different users may need the system to perform a different main task.

Open Ended

A the beginning of the lesson, you saw how us, human, execute a program for a Tic Tac Toe game.

What do you think it would take for a machine to be able to execute that program?

Lesson 2: Under the Hood

​In this lesson, you will learn:

• how to describe the hardware components used in computing systems

• how the components work together to execute a program

• how all computing systems, regardless how they look, are similar in structure (architecture).

New key term: 'Specs'
'Specs' is short form for 'specifications'.
It is a table of hardware components in a computing system and the technical characteristics.

​Good Struggle

GOOD STRUGGLE

​Read the following instructions carefully:

Link 1 : takes you to a 'Specs' file, which contains specs of a range of modern computing systems.​ You must read the information in the file very carefully.
Link 2: takes you to a Google Form activity sheet, where you'll have to answer questions about the 'specs' file.
LINK 1 : Specs File
LINK 2: Google Forms Activity

​Processor, Memory, Storage

Look at the correct answers and pay attention.

​Processor, Memory, Storage

Computing systems need a processor, memory, and storage. Modern systems also rely heavily on communication between them.

​Processor, Memory, Storage

Computing systems without input/output devices can connect to such devices. Input and output is always present in computing systems.

​Insight

Diverse computing systems have strikingly similar components:

all computing systems are similar in structure (‘architecture’).
Let's see what the common components do

How they function together in order to execute programs!

The  storage  (secondary memory) is the set of components that stores programs and data.

Storage is persistent: it retains its contents when the power is off.​

​What does 'storage' do?

​Storage device used inside desktop PCs and laptops. It has mechanical parts.

Hard Disk Drive

​Storage device used in new generation of PCs and laptops. It is all electric circuits with no moving parts.

​​Solid-State Drive

It is used for moving data from one device to another. It connects to the computers via USB port.

​​USB flash drive

It is used as an extension of storage in smart phones, digital cameras, tablets, etc.

​​SD card

Match

Match the following:

Hard Disk Drive

(HDD)

Solid State Drive

(SSD)

SD Card

USB Flash Drive

Compact Disc

(CD)

• Hard Disk Drive

  (HDD)

• Solid State Drive

  (SSD)

• SD Card

• USB Flash Drive

• Compact Disc

  (CD)

The main memory is the component that stores the programs and data currently in use.

Memory is volatile: its contents are lost when the power is off.

The main memory is commonly referred to as RAM (random-access memory).

​What does 'memory' do?

Random-Access Memory

​How does it work with other components?

When a program must be executed, it is loaded from storage in memory, along with the data required.

Any new or modified data must be saved from memory to storage.

​​When a program must be executed, it is loaded from storage in memory, along with the data required.

Any new or modified data must be saved from memory to storage.