Ares

COMPUTER

• A computer is a machine that accepts data, process it and then store or display the results. It comprises hardware and software. All general-purpose computers require central processing unit (CPU), memory, mass storage device, input device and output device.
  
  
  TYPES OF COMPUTER


• Supercomputer


• Mainframe


• Mini computer


• Micro computer
  
  SUPERCOMPUTER
  v A broad term for one of the fastest computers currently available.
  v Largest and most powerful computer.
  v Able to process large amount of data quickly.
  v Used for immense amounts of mathematical calculations (number crunching)
  Eg: weather forecasting, fluid dynamic calculation, nuclear energy research, and supercomputer military defense system, banking and space exploration programmes
  v Major universities, military agencies and scientific research laboratories are heavy users.
  v Manufacturers: Cray Research and Fujitsu.
  
  
  
  MAINFRAME
  v Mainframe was a term originally referring to the cabinet containing the central processor unit or "main frame" of a room-filling Stone Age batch machine.
  v After the emergence of minicomputer, the traditional big iron machines were described as mainframes.
  v Large computer in terms of price , power and speed (measured in millions of instructions per second(MIPS) , usually 26-30657MIPS). It can support more than thousands of user simultaneously.
  v Designed to handle very high volume input and output like giga-record or tera-record.
  v For critical applications, typically bulk data processing such as census industry and consumer statistics, Enterprise resourcing planning, and financial transaction procession.
  v Nearly all mainframes have the ability to run (or host) multiple operating systems and thereby operate not as a single computer but as a number of virtual machines.
  v Also known as “Enterprise Server”.
  v Early of 2006, IBM Mainframes dominate the mainframe market at well over 90% market share.
  v Manufacturers : IBM(International Business Machine Corporation) and HP(Hewlett-Packard)
  
  
  MINI COMPUTER
  v Minicomputer is a largely obsolete term for a class of multi-user computer that lies in the middle range of the computing spectrum, in between the mainframes and micro computer.
  v Is a multiprocessing system capable of supporting from up to 200 users simultaneously.
  v Used by medium to large organizations
  v The first minicomputer was Digital Equipment Corporation’s 12-bit PDP-8, launched in 1964.
  v Manufacturers include IBM, ICL and DEC.
  
  MICRO COMPUTER
  v Is a computer with a microprocessor as its central processing unit
  v Occupy physically small amounts of space.
  v As of June 2008, the number of personal computers world wide in use hit one billion.
  v Different types of microcomputer:

(a) Personal computer or “PC”
- Small, relatively inexpensive computer designed for an individual user.


(b) “Macs” (made by Apple Macintosh)
- I s a brand name which covers several lines of personal computer designed , developed and marketed by Apple Inc.
- On october 2007, Apple released its forth quarter results , reporting shipment of 2164000 Macs.

(c) Personal Digital Assistant (PDA)
- a hardware specification for handled sized computer
- has many of the capabilities of modern dekstop

(d) Palmtop
- a small computer that literally fits in your palm
- mostly do not include disk drives, but may contain slots in which you can insert disk drives, modems and other devices.

(e) Laptops or Notebooks
- an extremely lightweight personal computer
- use a variety of techniques , known as flat-panel technologies
- cost about twice as much as equivalent regular sized computer.
- Come with battery packs