Course 1 Week 1 Flashcards
What is Information Technology?
The use of digital technology like computers or the Internet to store and process data into useful information.
What is a computer?
a device that stores and processes data by performing calculations
What is the QWERTY keyboard layout called?
Cordelia
What was one of the earliest computers and when was it invented?
Abacus, invented in 500 BC to count large numbers
When was the mechanical calculator invented?
17th century by Blaise Pascal
When was the programmable loom invented?
1800s by Joseph Jacquard using punch cards
What were punch cards?
A sequence of cards with holes in them to automatically perform calculations instead of manually entering them by hand
Who invented the difference engine and analytical engine?
Charles Babbage
Who developed the first algorithm for the analytical engine?
Ada Lovelace
What is an algorithm?
A series of steps that solve specific problems
What is cryptography?
the art of writing and solving codes
What replaced punch cards and when?
Magnetic tape in the 1950s
What is a compiler?
a computer program that translates code written in one programming language often into the machine’s native language.
(translates source code into machine code)
A compiler is a program that translates a computer language that is easy for a programmer to understand to a series of bits (representing instructions) for the hardware
What is binary system? How does a computer use it? And what is it also known as?
The binary system is a computer’s way of representing data using 0s and 1s.
computer uses binary system to communicate
(binary digits (bits) grouped into 8 numbers )
Also known as base-2 numeral system (power of 2)
What is a group of 8 bits called?
a byte
What does base-2 system mean?
two to the eighth
Each byte can store how many characters?
1
What’s the maximum value we can have with 8 bits in a byte?
256
Since there are 8 bits with two values each, the highest number of possible values is 2 to the power of 8, or 256.
(the #’s are only 0-255 which is 256 values)
What is the highest decimal value a byte can represent?
255
There are 256 values in a byte, from the decimal number 0 to 255, which is the highest value since the count starts at 0.
Why did UTF-8 replace the ASCII character-encoding standard?
UTF-8 replaced the ASCII character-encoding standard because it can store a character in more than a single byte.
What is character encoding?
assigning binary values to characters so we can read them
(dictionary for us for computer speak)
What is abstraction?
To take a relatively complex system and simplify it for our use
What is ASCII? What does it represent?
The oldest character encoding standard used is ASCII. It represents the English alphabet, digits, and punctuation marks
What is the decimal-form base 10 system?
The decimal number system has 10 possible numbers you can use ranging from 0-9
The base of a number system tells us how many unique digits are used to form a number in that system.
(others like binary, hexadecimal, dozenal, octal use others)
What is Linux OS? Where is it most used?
Linux is one of the largest open source operating systems used heavily in business infrastructure and in the consumer space
What are logic gates?
Electrical components that tell a computer how to perform binary calculations (by allowing transistors to do more complex tasks)
Allow transistors to do more complex tasks, like decide where to send electrical signals depending on logical conditions
What is open source?
This means the developers will let other developers share, modify, and distribute their software for free
What is a transistor?
In a microchip, it’s an electrical current that acts as a switch.
If it lets current through it represents binary digit 1, cuts it off it’s a 0.
What is the NOT gate?
only has 1 input signal, and outputs a signal with an opposite binary state.
What is the AND gate?
2 input signals. Outputs an “on” signal only when both inputs are “on”.
What is the OR gate?
2 input signals, outputs an “off” signal only when both inputs are off.
What is the XOR gate?
2 input signals, “on” signal when only one of the inputs are “on”.
What is the NAND gate?
2 input signals, if both inputs are “on” then output is “off”
What is the XNOR gate?
2 input signals, “on” only when both are the same on or off input.
Are logic gates physical electrical components?
Yes, plug them into circuit board
What is a circuit?
electrical system that perform the binary calculations of the logic gates linked together
How do you link logic gates? 2 answers
- letting output from one gate serve as input for another gate
- by using same inputs for multiple gates
What is an example of a decimal number?
330, 250, 44 million, etc
What’s an example of abstraction?
Driving a car, don’t know how to operate what’s under the hood but we can drive it because it hides complexity by providing a common interface (wheel, pedals, etc)
different cars operate the same way even if engine is different
OR
error message, don’t have to dig into the code
What are the four main layers a computer can be cut into?
- OS
- Hardware
- Software
- User
