CompSci Autumn 2022/23 Modern Computers Flashcards
1.1 Euclid
Mathematician who lived around 300 BC. Invented algorithms.
1.2 Algorithm
A sequence of instructions that can be followed to complete a specific task
1.3 Pingala
Mathematician who lived around 200 BC. Invented the binary number system.
1.4 Binary numbers
Numbers which consist of only 1s and 0s. Known as base-2 as there are only 2 different digits.
1.5 Converting Binary to Decimal
1.Fill the top row (right to left, starting at 1 and doubling each time you move left) 2.Fill the binary number in underneath 3.Add any columns that contain a 1.
1.6 Converting Decimal to Binary
1.Fill the top row (right to left, starting at 1 and doubling each time you move left) 2.Starting from the left, add the numbers to reach the decimal number. 3.Place a 1 in any columns that are needed.
1.7 Bitmap Images
A bitmap is a grid of binary data representing the values of pixels in an image
1.8 Pixels
Bitmap images are made up of many single points of colour. These are called pixels (short for picture elements).
1.9 Resolution
The total pixels in an image which is expressed as a calculation of the pixels as width x height.
2.1 Bit (b)
A binary digit. The smallest digit in the binary system. 0 or 1.
2.2 Byte (B)
Eight bits. Example: 01011011
2.3 Kilobyte (kB)
1000 bytes
2.4 Megabyte (MB)
1000 kilobytes
2.5 Gigabyte (GB)
1000 megabytes
2.6 Terabyte (TB)
1000 gigabytes
2.7 Secondary Storage
Holds programs and data, even when the computer is switched off. All data is stored physically as binary.
3.1 Charles Babbage
Mathematician who lived in the 1800s. Created mechanical computers for solving mathematical problems more quickly.
3.2 Ada Lovelace
Mathematician who lived in the 1800s. Realised machines could do more than maths, and wrote the first computer program for one of Babbage’s machines before it was built.
3.3 Hardware
Physical parts of the computer, both internal and external.
3.4 Software
Programs - instructions and data which run on a computer system.
3.5 George Boole
Mathematician who lived in the 1800s. Created Boolean Logic
3.6 Boolean Logic
AND, OR, NOT gates used to direct electricity around a circuit
3.7 Central Processing Unit (CPU)
Executes programs – performs mathematical calculations and comparisons.
3.8 Alan Turing
Mathematician who lived in the mid-1900s. Invented the Turing machine, which is what modern computers are based on.
3.9 Random Access Memory (RAM)
Required to allow multiple programs to run on one computer.
4.1 Networks
Two or more computers connected together to communicate.
4.2 Tim Berners-Lee
Computer Scientist still working today. Invented the World Wide Web and allowed it to be used for free.
4.3 The Internet
A worldwide international network, used to share information on websites and communicate e.g email
4.4 World Wide Web (WWW)
A collection of websites which can be accessed through the Internet.
