Types and Components of Computer Systems •Hardware & Software • Hardware • Tangible physical components of a computer system • You can feel it or touch it • Hardware can either be internal or external Internal Hardware Devices •Processor •Motherboard •RAM & ROM •Video & Sound Cards •Internal Storage devices like Hard disk drive(HDD) & Solid state drive(SSD) External Hardware Devices •Monitor •Keyboard •Mouse •Printer •External Storage Device Peripheral devices: Are all devices that can be attached to a computer system, e.g. digital camera, scanner. All devices than the CPU. Internal Computer Hardware: 1. Central Processing Unit (CPU): The CPU interprets and executes the commands from the computer hardware and software. It is part of the motherboard. A microprocessor •is a single integrated circuit found in PCs and many household devices. CPU made up of: •Control unit: controls the input and output devices associated with the computer •Arithmetic and logic unit: carries out calculations and makes logical decisions •Immediate access store (RAM) Motherboard: The motherboard is a printed circuit board found in all computers. The motherboard allows the processor and other computer hardware to function and communicate with each other. It acts as a kind of ‘hub’ that other computer devices connect to. It contains several sockets and slots to connect the other components. Internal Hard Disk Drive (HDD) or Solid State Drive (SSD) •computer’s main internal storage •this stores the application software, operating system and files •they have fast data transfer rates and data access times •large memory capacity to store data RAM: • Random access memory (RAM) is an internal chip where data is stored temporarily • Memory can be written to and read from • Stores anything that needs to be changed • All program and data being used are on RAM • Contents lost when computer is turned off • Referred to as volatile memory ROM: •Read only memory (ROM) is memory used to store permanent information •Used to contain configuration data for a computer etc. •Chips cannot be altered, only read from •Data not lost when computer is turned off •Referred to as non-volatile memory BIOS: • ROM contains boot file, referred to as BIOS (basic input/output system) • Tells computers what to do when it first starts • Does hardware check when computer is turned on • Then it loads operating system into RAM • BIOS stores date, time and system configuration CMOS (Complementary Metal Oxide Semiconductor): battery powered non-volatile chips used by the BIOS to store date and time. Video Card Video Card Video cards are usually made up of: • a processing unit • memory unit (usually RAM) •a cooling mechanism • connections to a display unit Sound Card Sound cards use two basic methods to translate digital data into analogue signals needed for speakers: • FM synthesis mimics different musical instruments according to built-in formulas • wavetable synthesis relies on recordings of actual instruments to produce sound Software •Programs that control computer systems •Set of instructions that make computer do something •You cannot physically touch software •Relates to ideas & instructions for using physical objects Two types of software: •Application software: • Programs that allow the user to do specific task • Design to carry out tasks • Can be general purpose software or custommade software (specialist software) • E.g. Spread sheets, databases, word processing Word processor is used to manipulate text documents. • Spreadsheet is used to organise and manipulate numerical data. • Database management system is used to organise, manipulate and analyse data. • Control and measuring software • Apps (short for Applications) refers to the type of software that runs on mobile phones or tablets. • Photo editing software • Video editing software • Graphics manipulation software System Software: • Is Programs that allow the hardware to run properly • Control computer's hardware and application program • Communicate with user • E.g. Operating system, device drivers, compiler For example: • Operating systems • Utilities help to manage, maintain and control computer resources. Examples: o antivirus o anti-spyware o backup of files o disk repair o screensavers • Device drivers allow hardware devices to communicate with the operating system. • Compiler translates a program written in highlevel language into machine code to be understood by the computer. • Linkers are used to put all the modules together to form a final program. Operating systems: Tasks for a typical operating system: control the operation of the input, output and backing storage devices supervising the loading, running and storage of application programs maintaining security of the whole computer system maintaining a computer log (which details computer usage) allowing communication between the user and the computer system (user interface)
