7. Videos

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Why does a computer need ROM as well as RAM?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Which storage would you choose for a tablet, and why?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Name three embedded systems in a car.

Open on YouTube ↗

An animated explainer of the RAID levels your teacher covers with NAS and SAN.

Watch and think:

• Which RAID level gives no protection at all?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• What does a NIC do?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• List four jobs of an operating system.

Open on YouTube ↗

What the kernel does and why it sits between programs and hardware.

Watch and think:

• Why can’t applications talk to hardware directly?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Give two utilities and the problem each solves.

Open on YouTube ↗

The principles of open source software and why organisations use it.

Watch and think:

• Give one benefit and one risk of open source for a business.

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Why store data in a database instead of a spreadsheet?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Which model suits a school sharing data across many PCs?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• What is stored in memory in a Von Neumann computer?

Open on YouTube ↗

A clear comparison of the two architectures in B1.

Watch and think:

• Why can a Harvard processor fetch an instruction and data at the same time?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Why do modern CPUs mix ideas from both architectures?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• What do the ALU and control unit each do?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Why don’t four cores make every program four times faster?

Open on YouTube ↗

Stretch: pipelining explained by a computer scientist.

Watch and think:

• What happens to a pipeline when the program branches?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• What is the difference between the MAR and the MDR?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Which bus is one-way and which is two-way?

Open on YouTube ↗

Stretch: what really happens when an interrupt arrives.

Watch and think:

• What does the CPU save before it handles an interrupt?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Why do computers use binary?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Convert 1011 0110 to denary.

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• What is an overflow error?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• What is −1 in 8-bit two’s complement?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Why is one hex digit worth exactly four bits?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• What does a left shift of 2 places do to the value?

Open on YouTube ↗

Stretch: an animated explanation of floating point.

Watch and think:

• What do the mantissa and exponent each control?

Open on YouTube ↗

BCD and where it is still used, e.g. digital displays and controllers.

Watch and think:

• Write 59 in BCD.

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Why did Unicode replace ASCII for most uses?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• How does colour depth affect file size?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• How do sample rate and bit depth affect quality?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• When must you use lossless compression?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• What is the difference between an array and a record?

Open on YouTube ↗

Stacks (last in, first out) and queues (first in, first out) explained.

Watch and think:

• Give a real use of a stack and a queue.

Open on YouTube ↗

Step-by-step matrix multiplication for D2.

Watch and think:

• Why must the columns of the first matrix equal the rows of the second?

Open on YouTube ↗

Stretch: what matrix multiplication means geometrically.

Watch and think:

• How can a matrix move or rotate a shape?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Why is serial used for long distances?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• What are start and stop bits for?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Why are protocols organised into layers?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• What is the difference between plaintext and ciphertext?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Why is a public key safe to share?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Why is a Caesar cipher easy to break?

Open on YouTube ↗

The Vigenère cipher from your encryption lesson, worked through.

Watch and think:

• Why is Vigenère harder to break than Caesar?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Which errors can a single parity bit not detect?

Open on YouTube ↗

Stretch: how CRCs catch errors.

Watch and think:

• Why is a CRC better than a parity bit?

Open on YouTube ↗

How forward error correction repairs data.

Watch and think:

• How can a receiver fix an error without asking again?

Open on YouTube ↗

Stretch: a beautiful explanation of error-correcting codes.

Watch and think:

• What extra information lets Hamming codes locate the wrong bit?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• When does an OR gate output 0?

Open on YouTube ↗

How logic gates add binary numbers.

Watch and think:

• Which two gates make a half adder?

Open on YouTube ↗

Stretch: the rules for simplifying Boolean expressions.

Watch and think:

• Simplify A AND (A OR B).

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• Which symbol shows a decision?

Open on YouTube ↗

A short revision video from the MrBrownCS series (also in the department video folder).

Watch and think:

• What do the arrows in a DFD show?

Open on YouTube ↗

Extra revision from the department video folder.

Watch and think:

• What factors affect network performance?

Open on YouTube ↗

Extra revision from the department video folder.

Watch and think:

• Why is Ethernet usually more reliable than Wi-Fi?

Open on YouTube ↗

Extra revision from the department video folder.

Watch and think:

• Which protocol makes sure packets arrive in order?

Open on YouTube ↗

Extra revision from the department video folder.

Watch and think:

• Which protocol sends email?

Open on YouTube ↗

Extra revision from the department video folder.

Watch and think:

• What does a firewall check?

Open on YouTube ↗