Computers π» | Data representation | 1.1 Flashcards
What system does a computer use to store data?
Computers use binary - the digits 0 and 1 - to store data.
What is the smallest unit of data in computing?
A binary digit, or a bit, is the smallest unit of data in computing.
What is a bit represented as?
The digit 0 or 1.
What makes up a computer processor?
Billions of transistors, tiny switches activated by the electronic signals it receives.
What is a transistor?
A transistor is a tiny device that regulates current or voltage flow and acts as a switch or a gate for electronic signals.
What do the 0 and 1 digits in binary represent?
They reflect the on and off states of a transistor.
What is a computer program?
Sets of instructions given for the computer to output.
What is the most basic low level type of code on a computer?
Machine code.
What is machine code?
Simple binary codes that activate the CPU.
Do humans write in machine code?
No, most humans write code in higher level languages that are more understandable, which are converted by a translator into binary instructions the processor can excecute.
What is encoding?
Encoding is when data on a computer is translated from one format to another. Everything on a computer looks like binary numbers in machine code to the processor. They are encoded into data formats to give them meaning.
Why are encoding formats standardized?
Encoding formats are standardized to help with compatibility across different platforms.
What is audio encoded as?
Audio is encoded as audio file formats, eg mp3, WAV, AAC.
What is video encoded as?
Video is encoded as video file formats, eg MPEG4, H264.
What is text encoded as?
Text is encoded in character sets, eg ASCII, Unicode.
What are images encoded as?
Images are encoded as file formats, eg BMP, JPEG, PNG.
What groups are bits organized into when representing larger amounts of data?
The bits can be organized into nibbles, byte, word, long words, and very long words.
How many bits are in a nibble?
4 bits.
How many bits are in a byte?
8 bits.
How many bits are in a word?
16 bits.
How many bits are in a long word?
32 bits.
How much data does a single computer memory cell hold?
A byte, or 8 bits.
How does a computer perform different jobs?
It executes the program instructions.
What is the CPU responsible for
~The CPU has many responsibilities! She is a full grown adult and has left school, so she has to pay taxes, manage money, and manage a family all on her own!~
~Life as a CPU is challenging, but worthwhile. Little transistors - I know it seems like a long way away, but YOU will some day work together to be a CPU. YES YOU WILL!!~
No, a CPU is responsible for performing both arithmetic calculation and logical operations.
~Welcome to Eranβs flashcardβs, where he adds completely unnecessary things to flashcards to make them more interesting.~
~i mean this should add some interest~
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What is a logical operation?
Less than or greater than, equal to, AND, OR, NOTβ¦
What is an arithmetic calculation?
Plus, minus, multiplied, divide - mathematical ones.
What is a logic gate?
A model of a logical operation in a computer, constructed theoretically using transistors inside a processor chip. A CPU has millions of these to perform logical operations.
What are the 3 number systems?
Binary, denary, and hexadecimal.
What is the base of the denary number system?
10.
What are the digits used in the denary number system?
0, 1, 2, 3, 4, 5, 6, 7, 8, 9
What is the base of the binary number system?
2.
What are the digits used in the binary number system?
0 and 1
What is the base of the hexadecimal number system?
16.
What are the digits used in the hexadecimal number system?
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F
What do the Digits A - F represent in the hexadecimal number system?
10-15, but as digits.
What is a memory dump?
A process in which the contents of the memory are displayed or stored, in the case of an application or system crash.
What are the other names for a memory dump?
A core dump, Blue screen of death (BSOD), or βBlue screen of errorβ (never heard this. is the syllabus trying to be less violent and more formal??)
What operating system are memory dumps more commonly found on?
Memory dump is a common problem found in various versions of the windows operating system.
What is a blue screen memory dump?
A blue screen memory dump is an error screen that comes up just before the system just gets rebooted, as the operating system can no longer function due to a variety of reasons. The RAM is dumped onto a data file.
How is a memory dump helpful?
A memory dump allows software developers and system administrators to diagnose or identify and resolve the problem that lead to the application / system failure.
How is hexadecimal used in memory dumps?
The hexadecimal number system is used as a shortcut notation in computer memory dumps. Since computer memory is inherently binary, hexadecimal shortens it. Each nibble is printed as a hexadecimal digit.
What is HTML?
HTML (Hypertext markup language) is a markup language used to write content on webpages. It uses and tags to write commands.
How is color specified on websites?
The color is specified according to the intensity of the Red, Green, and Blue, each represented by 8 bits. 24 bits altogether to represent a web color. Each Parameter are represented as an integer from 0-255
How does hexadecimal aid in web color?
The 24 bits that would otherwise be represented as integers from 0-255 are shortened to a 6 digit HEX(adecimal) code.
Why are HTML color codes in Hexadecimal?
It uses fewer characters, making the file smaller and allowing the page to load faster over a slow network connection.
What is a MAC adress?
MAC (Media Access Control) address is a unit number associated with network interface cards which identify as a particular machine/device. This allows all devices to uniquely identify themselves on a computer network such as internet.
How many bits long is a MAC adress?
48 bits long. It can theoretically be assigned to 281 billion computers.
How is a MAC address written?
As a sequence of 12 hexadecimal digits like:
MM-MM-MM-SS-SS-SS or mm-mm-mm-ss-ss-ss
The first 6 βMMβ digits represent the identification number. The second 6 βSSβ digits represent the serial number of the device.
What is a URL?
A URL βUniform Resource Locatorβ is the address of a web page used to request a page from a web server in a browser.
How is hexadecimal helpful in web adresses?
Web addresses are limited to only the ASCII character set. If the URL contains a character outside the ASCII character set, it is converted to an ASCII formal with a percentage (%) sign followed by 2 hexadecimal digits.
How is a space represented in a web address?
With a β+β or a β%20β
How is hexadecimal useful in machine code?
To address low level components we use addresses with hexadecimal values to shorten it.
How is hexadecimal useful in debugging?
It is often used to refer to a certain error message.
What are the advantages of hexadecimal?
- It is more concise, which allows you to store more information with less space.
- It is fast and simple to convert between hexadecimal and binary
- It makes life easier for humans, as it allows for grouping of binary numbers, making it easier to understand. Also, less digits reduces the chances of error occurring.
What is 8 bit overflow?
Processors use 8 bit registers, so if too many bits are added to the register (11111111+1), the CPU drops the overflow digit and thinks the answer is 0.
What digit is a negative sign bit?
1
What digit is a positive sign bit?
0
All unsigned binary numbers are __
Positive
What is twos complement?
A method of representing signed numbers.
Write positive number - flip the bits - add 1
The twos complement of a positive number is __
The same as normal.
What is a character set?
A complete set of the characters and their number codes that can be represented by a computer system.
How are binary codes used to represent characters?
Each character must be stored as a unique number called a character code if a computer system is to be able to store and process it.
What does ASCII stand for?
American Standard Code of Information Interchange
What is ASCII?
A character encoding that uses numeric codes to represent characters.
Standard ASCII uses __ bits to represent __ characters.
Standard ASCII uses 7 bits to represent 128 characters.
Extended ASCII uses __ bits to represent __ characters.
Extended ASCII uses 8 bits to represent 256 characters.
Standard ASCII is enough to represent __
All standard English letters, numbers, and punctuation symbols
Extended ASCII is enough to represent __
Special characters and characters from other languages.
In extended ASCII, all additional binary values start with a _
1
What is unicode?
A universal character encoding standard that defines the way individual characters are represented in text files, web pages, and other types of documents.
Unicode is enough to represent __
Characters from all languages around the world.
Unicode can represent upto __ characters, using __ bytes each
Unicode can represent upto about 1,000,00 characters, using 4 bytes each
What are the two kinds of unicode?
UTF-8 and UTF-16
UTF-8 uses _ bytes to represent common english characters
one byte
UTF-8 uses two bytes to represent __
European, Hebrew, and Arabic characters
UTF-8 uses 3 bytes to represent _
Chinese, Japanese, Korean, and Other Asian characters.
UTF-8 uses 4 bytes to represent __
Additional unicode characters.
