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Unit 2 - Computer Science

1. CPU

   • The CPU is the brain of the computer
   • Its a microprocessor
   • Central Processing Unit
   • The CPU performs tasks of fetching, decoding, and managing the execution of instructions
   • Clock Speed
     • The clock speed is the rate the CPU works.
     • The higher the clock speed the higher performance
     • The lower the clock speed the lower performance
   • Cache Size
     • Cache memory is a small chunk of fast memory that is built into the CPU
     • It greatly increses the speed of the computer
   • The fetch execute cycle
     • is the continuous cycle a computer works in
     • The way in which the computer fetches, decodes and executes instructions

2. Input and Output devices

   • E.g. keyboard, speakers, mouse, scanner etc
   • Without Input and output devices, you wouldn't be able to use your computer
   • Some input and output devices are required because you need a monitor to be able to see your computer screen
   • Some people require more advanced technology for example programming equipment

3. Memory

   • ROM is non-volatile storage and does not require a constant source of power to retain information stored on it
   • RAM is a volatile storage and does require a constant source of power to retain information stored on it
   • ROM is used primarily in the start up process of a computer, whereas RAM is used in the normal operations of a computer after starting up and loading the operating system
   • RAM can store multiple gigabytes (GB) of data, up to 16gb or more. ROM typically stores only several megabytes (MB) of data, up to 4mb or more.
   • Writing data to ROM is a slow process, whereas writing data to RAM is a faster process
   • Cache memory, also called CPU memory, is random access memory (RAM) that a computer microprocessors can access more quickly than it can access regular RAM

4. A binary code represents text or computer processor instructions using the binary nmber system's two binary digity, 0 and 1. A binary string of eight binary digits (bits) can represent any of 256 possible values and can therefore correspong to a variety of different symbols, letters or instructions

   • Binary
     • If the number goes above 10 it changes to letters so if you get 12 your answer will be C. if you get 7 your answer will be 7