computer science 💀

The Associative Law means

Numbers will equal the same, no matter which way round they are.

Data + Meaning = ?

Information

ASCII stands for

American standard code for information interchange

How many cores is a dec core

10

What is lossless compression

Is not permanent and temporary

In ASCII, how many bits is 1 character

8 bits

How do you work out the compression file size with only the original size and compression ratio

E.g 200MB 10:1 ?

Divide 200 by 10, then multiply by 1

What are the main components inside a CPU

Arithmetic Logic Unit

Register

Control Unit

What is overflow

Overflow is where a value exceeds the maximum value a register can hold. If you had the value 10000000 stored in an 8 bit register, the result would be 00000000, as it’s lost the leading one, destroying the value.

How many bits in a nibble

4

What is lossy compression

Permanent

What types of Meta Data are included in all files

File name

File type

File size

How to convert binary to Denary

Add headings above numbers, circle the values with 1 underneath then add them together

How many cores in a hex core

6

To go from bits to bytes you…

Divide by 8

What is cache

The fastest way to process data, type of RAM.

More the better, but is expensive

Has 3 levels, each having a high/low clock speed of memory and a high/low amount of memory

What are the key components of a computer

CPU

Motherboard

RAM

What is the Idempotent Law

A.A = A

A +A = A

Level 1 cache is allocated to

1 single core

The fastest memory, but the smallest amount

To up from bytes to bits you…

Multiply by 8

How many calculations per second is 1GHz

1000MHz, which is 1,000,000,000 calculations per second

Binary shifting

Shifting is where all the numbers shift one place left or right.

PC

Program Counter

CIR

Current Instruction Register

ACC

Accumulator

MAR

Memory Address Register

MDR

Memory Data Register

What is this

NOT

What is this?

XNOR

What is this?

NOR

What is this?

NAND

What is this?

AND

What is this?

XOR

What is this

OR

The distributive law

the wave thing, expanding

A + (B . C) = (A + B) . (A + C)

DeMorgan’s Law

Break the not symbol and change the sign

How are samples stored in computers

1. Record analogue sound

2. Convert to binary (analogue to digital conversion)

3. Can be stored to create digital version

Benefit to ASCII set

It is simple and all American computers can easily and quickly communicate using 8 bits

Limitation to ASCII

It only supports American English, meaning other languages such as Japanese aren’t supported.

Describe the relationship between a kilobit and kilobyte

1 KB = 8 Kb, Kb is used as a measurement for transfer speed, kilobytes is used to measure storage, there are 1024 B in 1KB, there are 1024b in 1Kb

State the effect of arithmetic shifts on 0011000 shift 2 places left/right

Left is multiplied by 4, right is divide by 4

IMAGE

Height x width x bit depth

SOUND

Bit rate x sample rate x length (s)

VIDEO

(Height x width x bit depth x frames per s) + (Sample Rate x Bit depth) X length of video in seconds

Possible amount of colours with 24 bits

2^24

The Complement Law

A AND NOT A is false, A OR NOT A is true

Presence Check

Checks data has been entered

Type check

Checks data is the correct data type

Length check

Checks the correct number of characters has been entered

Range check

Checks data is within a valid range

Format check

Checks the format of data

What is RISC

RISC (Reduced Instruction Set Computer) is a processor architecture that uses a small set of simple instructions that execute quickly, often is one clock cycle.

What is CISC

CISC (Complex Instruction Set Computer) is a processor architecture that uses a large set of Complex instructions, where a single instruction may perform multiple operations.

Environmental Impact of Disposing Hardware

Mining raw materials damages habitats (copper, lithium)

Factories produces chemical waste and pollution

Environmental Impact of Manufacturing Hardware

Old devices contain materials that damage the environment if not disposed of correctly (E-Waste)

Burning E-Waste can release harmful gasses

What are 6 software development tools that are usually integrated into IDEs?

Run (Compiler and Interpreter)

Editor

Libraries

Debugger

Break point

Auto indent

What is sound sampling

Sounds are stored on a computer by sampling sound at set intervals. The no. of samples taken per second is known as sample rate. Each sample is stored on a computer in binary, the more binary values available per second, the higher quality of sound (sample rate)

What is bit rate

Is storage required for 1 second of sound calculated from sample rate x bit depth. Sounds can also include different channels each channel is a different audio track. These are used for surround sound audio

Advantages of waterfall model

Used clear navigation and structure (clear)

Gain greater understanding form the beginning (progressively educating)

Has a project specific timeframe (punctual)

Can easily step into projects at different times (free)

Initiative and collaboration with team members

Disadvantages of waterfall model

Difficult to make changes (Not malleable)

Limited collaboration with clients

Only effective for smaller projects (no big)

Working models and testing do not take place until later changes

High risk on misunderstanding (misinterpretation)

Advantages of Agile Model

Adapts to change, making it easier to change requirements after the project is underway

Early error detection, which prevents complications later on in the project

Close user collaboration

Disadvantages of Agile Model

Limited documentation, making it harder for new members to the team

Harder to measure progress because as there’s no project specific timeframe

Advantages of spiral model

Software is produced early in development (productive)

Provides opportunities for early prototypes

Strongest for handling risk management (risk managing)

Can easily change requirements (malleable)

Better for large and more complicated systems (no small)

Disadvantages of spiral model

Expensive

Increases risk of scope creep

Can be difficult to estimate time scale (not punctual)

Requires higher level of expertise (you need to be smart first)

Can have fewer comprehensive documents