computer science revision

computer science revision

1. CPU

   • Components
     • CU
       • Control Unit
       • Coordinates all the CPU's actions in the fetch-decode-execute cycle.
     • ALU
       • Arithmetic Logic Unit
       • Carries out mathematical and logical operations
     • Clock
       • Regulates the speed and timing of all signals and computer finctions
   • The purpose is to continuously fetch, read, execute instructions in memory by repeatedly carrying out the fetch-execute cycle

2. Secondary Storage

   • Solid State
   • optical
     • Highly portable and lightweight
     • The speed is up to 50MB/s
     • The capacity from 650MB to 50GB
   • Magnetic
     • The capacity is up to 16TB
     • Speeds up to 200MB/s
     • Internal drives are not portable
     • External drives are in similar size to a large smartphone