Binary Systems
Computer Science: OCR A Level, topic 4.3.1
Binary Systems
Computer systems store and process data as binary digits.
Why use binary form?
- Underneath the surface computers are electrical devices that process information by controlling the flow of electricity through billions of wires and transistors (electrical switches) inside the central processing unit and other components.
- The presence of electricity represents a 1, and an absence of electricity represents a 0.
The transistor
- Transistors are electrical components made from semiconductor materials that can act as electrically-controlled switches.
- Transistors can be used to temporarily store data, for example in some forms of primary storage (memory).
Transistors in the CPU
- Inside a Central Processing Unit (CPU), transistors are arranged into circuits to perform operations such as calculations when electricity is passed through them.
- For example, transistors can be arranged to form an 'adder' circuit that can accept two binary numbers, and output the sum of their values.
- Modern CPUs contain over 3 billion transistors, allowing them to perform billions of calculations per second.
Test yourself on Binary Systems
What represents a 1 in most modern computers?