ICT AS

personal computers

personal or individual use, does not only refer to IBM compatible machines, but all systems for personal use. prices have decreased and performance improved since mid eighties due to development of components. standard for personal computing is now the multimedia machine, the list of items for the multimedia machine is;

• base unit
• visual display unit
• keyboard and mouse
• colour printers laser or inkjet
• speakers or sound systems
• secondary storage HDD FDD CD writer DVD
• internal modem for internet link

• systems made up of standalone machines in the use of commerce;

  • EPOS- electronic point of sale. enables vendors to process sales and organise stock control systems more effectively through the use of barcodes
  • EFTPOS- electronic funds transfer point of sale- developed from EPOS, inaugurating the cashless society. with EFTPOS, debits and credits can be allocated to current account balances and requests for payment applied to credit card accounts
  • E-COMMERCE-this technology involves the use of the internet to 'do business'. it can be used to purchase services or products

  the potential of hardware used in commercial systems is still being explored. use of modems and internet powered growth of virtual shopping and electronic commerce . hardware for commercial systems tends to be more robust than its counterpart in personal computing, and is tailored accordingly. the market for this is dominated by companies such as Dell, IBM,etc

• industrial computers

hardware is further specialised. apps and capabilities range from control in bottling plants to safety equipment in nuclear power stations. real systems developed after consideration of possible outcomes dervived from simulations and modelling scenarios

industrial systems are aimed at situations that ;

--> could be dangerous to humans

--> involve boring repetitive tasks

-->are low on the list of desirable (though non dangerous) jobs

-->require a level of precision with low tolerance

the microprocessor

• ALU-arithmetic logic unit, the part of a microprocessor that processes and manipulates data
• accumulator a storage register within the ALU that holds data currently being processed
• arithmetic register a storage register that holds both the results of calculations and the operands used to calculate
• CU-control unit,used to manage the operation of the micropocessor, ensuring that data gets from one location to another as required
• Registers-used as temporary storage. some (accumulator and arithmetic register) are utilised during the 'fetch, decode and execute' cycle. others are reserved for use by the program being executed

• Program counter
• address counter
• memory address register
• memory buffer register

Busses

in order for each of the elements of a microprocessor to fulful their tasks, they need to be supplied with data. this is done via the Bus

-->address bus- manages addresses and indexes

-->Data Bus-ferries data to and from the ALU

-->Control Bus- oversees instructions to input/output

Busses

in order for each of the elements of a microprocessor to fulful their tasks, they need to be supplied with data. this is done via the Bus

-->address bus- manages addresses and indexes

-->Data Bus-ferries data to and from the ALU

-->Control Bus- oversees instructions to input/output

Cards

cards are PCBs (printed circuit boards) placed inside a computers base unit, which create connectivity between the devices. types are:

• motherboard or mainboard. houses the microprocessor and main memory. it is a PCB with space for one or more microprocessors RAM and expansion slots for other cards or items of hardware
• interface card. permits communication with peripherals and is plugged into an expansion slot
• parallel port. standard interfae card that allows both input and output at high speed. data is transmitted and received in small groups simultaneously. also known as centronics card. mostly used for rpinting or game play
• serial port another standard interface card that is also known as RS232. data is transmitted and received 1 byte at a time. data transmission is slower that with a parallel port but is more reliable over distance. 1 common use is for a mouse or keyboard

• USB port the universal serial bus attempts to solve the problems of connecting devices to computers. the ports already supplied had specific hardware that would need to use them so a new form of connection was required

Memory-

even the most simplest tasks, such as sorting tow numbers ino order of size, cannot be achieved without memory and no permanent records of work could exist without memory

main memory

• Cache. very fast memory utlised for holding frequently used data. it lies between the micorprocessor and RAM
• RAM(random access memory). memory used as temporary storage. RAM is not pre-filled. RAM becomes occupied by data when the computer is in use. this will be a mixture of data used to operate the computer and data used to run programs
• ROM(read only memory) where instructions are pernanently etched at manufacture. the contents of ROM cannot be altered. some bsic instructions for booting up of the system will be ROM-based to ensure system access