Computer systems

Computer systems

1. A computer is a machine that processes data

   • The purpose of a computer is to take DATA, PROCESS it, then OUTPUT it. Computers were created to help process data and complete tasks MORE EFFICIENTLY than humans.
   • A COMPUTER SYSTEM consists of HARDWARE and SOFTWARE that work together to process data/complete tasks.
     • Hardware is the PHYSICAL stuff that makes up your computer system, like the CPU, motherboard, monitor and printer.
     • Software is the PROGRAMS or APPLICATIONS that a computer system runs e.g. an operating system, a word processor or video game.
   • There are MANY TYPES of computer system. These range from small devices like calculators and watches, up to large SUPERCOMPUTERS used by banks or for scientific applications. Computers may be GENERAL PURPOSE (designed to perform MANY TASKS, e.g. PCs and tablets) or DEDICATED SYSTEMS (designed for ONE PARTICULAR function, e.g. controlling traffic lights or an aeroplane).

2. Embedded systems are computers inside a larger system

   • EMBEDDED SYSTEMS are computers BUILT INTO OTHER DEVICES, like dishwashers, microwaves and TVs. They are usually dedicated systems.
   • Embedded systems are often used as CONTROL SYSTEMS - they MONITOR and CONTROL machinery in order to achieve a desired result. E.g. in a DISHWASHER the embedded system could control the water pumps and water release mechanisms, manage the various dishwasher cycles and control the thermostat to keep the water at an appropriate temperature.
   • As they're DEDICATED to a single task, embedded systems are usually easier to DESIGN, cheaper to PRODUCE, and more EFFICIENT at doing their task than a general purpose computer.

3. Computers contain components which work together

   • Power supply - supplies power to motherboard, optical and hard drives, and other hardware.
   • Case cooling fan - extracts hot air from the computer case.
   • CPU heat sink and cooling fan - keeps the CPU at a steady temperature (CPUs generate a lot of heat).
   • CPU (hidden under the heat sink) - the most important component. Does all the processing.
   • Optical drive - for read/writing of optical discs.
   • RAM sticks (computer memory).
   • Motherboard - The main circuit board in the computer, where the hardware is connected.
   • Hard Disk Drive - Internal secondary storage.