By: Gurman Khangura INT 9 Block: 3

 Computers have been for a long time, with the development of the abacus.  The abacus was a rack with sliding beads to perform computations.  In 1642, Blasie Pascal, invented a numerical wheel calculator. The Pascaline was a system with movable dials to do math with eight digits.  In 1812, Charles Baddage invented a machine called the Difference Engine. The Difference Engine was a machine performed calculations and printed them out. After 10 years of labor, he invented the Analytical Engine.  The Analytical Engine was designed with conditional decisions, such as “input”, “memory”, “processing unit”, and “output device”.  In 1820, Charles Xavier Thomas de Colmar invented the arithometer, that was capable of doing addition, subtraction, multiplication, and division.  In the 1900 Hollerith invented a system in which data was stored on punch cards.

 The first generation of modern computers was introduced during World War II.  The project ENIAC was started in 1943 and was completed in The ENIAC was a huge device that weighed about 30 tons.  It was designed to calculate ballistic trajectories. The ENIAC could perform complex calculations faster than any other calculating device. The ENIAC could calculate a 60 seconds trajectory in 30 seconds, a skilled that would have taken a skilled person twenty hours to calculate.  The ENIAC gave up eventually and better computers came up such as the EDVAC and UNIVAC.

 In 1956, the second generation of computers was started of by the shift from huge, heavy, bulky, failure – prone vacuum tubes to transistors.  Transistors use an electrical charge, allowing it to alternate between an insulator and conductor.  As the time passed by the transistors paved the way for much smaller, faster computers.  During this same time, advances in printers, disk, and tape storage, memory, and stored programs allowed computers to become multifunctional devices.  Machine language: a purely binary system of 1s and 0s that communicates instructions directly to the computer’s hard-ware.  Assembly language: to represent a series of 1s and 0s.  Each assembly instruction corresponds to one machine-language instructions.  In the time, computer scientists developed high-level languages such as COBOL and FORTRAN.

 Jack Kilby and Robert Noyce invented the integrated circuit (IC) in the late  ICs produce much less heat than transistors.  The heat allowed more components to fit onto a single chip.  Microchips, allowed computers to shrink from the size of a room to the size of today’s laptop computers.  Computers have become even smaller and more reliable.

 Computers have become readily available (in size, cost, and reliability)  The first affordable computer were the PC, the MITS Altair 8800, in the 1974  Apple I and II and the Commodore PET, were introduced to the public  In 1981, IBM released its first PC  By, 1990, 65 million PCs were use  20 years after the invention about 1 billion computers were used worldwide  Without computers in the world would by hard  Computers keep track of our bank accounts, control air traffic, and help design buildings, aircraft, and automobiles and much more

 The hardware is the physical components of the computer  The principal concepts and technology behind the hardware are the same  It would be very difficult to work with computer without input and output devices  Input devices allow an individual to enter information so that the computer can do the work it is designed to do.  Other types of input devices are scanners and digitizing pads, or even wheel of the car  Output is the feedback that lets us know what is happening on the inside of the computer  The most common computer output device today is the computer monitor  Another modern output device is the printer

 The single most important component is the central processing unit, CPU  It is the brain of the computer, it performs the very basic functions, such as addition, subtraction, multiplication, and division  It can do these operations millions and even billions of times every second  Transistor are inside the CPU  All the information goes through the CPU from s to calculations  The CPU has no memory  Random-access memory (RAM) is a storage unit for data going to and coming from the CPU

 For long term storage of data your computer uses hard drives, C-ROMs, and floppy disks  Each of the devices uses different techniques for storing and retrieving data  Storage capacity is a measure of how many bits of data the medium can store  The primary storage device in a computer is the hard drive  Hard drives typically store data on a series of magnetic recording platters made of high- precision aluminum or glass  Although hard drives provide large amount of space for storage, they are not typically portable from one computer to another  A typical storage device in use today, the recordable CD (CD-R)  Other types of removable storage include optical drives, Zip drives, and USB

 Networking is the most explosive growth area of the most explosive growth area of the computer industry  It connects computers to share files, programs, and other resources and much more  Media are the physical connections that join all the network’s parts so they can communicate  The media connect the network to the individual computer, which are called noble  Each node contains a network interface card (NIC), which allows the data to go through the network and its nobles  Nodes can be connected to each other,or to the central computer called a server  The server can hold programs and data that are used by everyone on the network  The layout of a network is called its topology, there are three common network topologies:  BUS- In a bus topology, all nodes are connected in a series, using a single cable  STAR- In a star topology, each node has its own connection to a central device, called a hub  RING- In a ring topology, all nodes are connected together in a circle

 Operating systems (OS), often called platforms, essentially perform two important jobs  The first thing that the operating systems do is manage the hardware and software  The operating system manages the various requests from applications software to the hardware  Second, operating systems provide a consistent interface for applications  Operating systems usually provide an application programming interface (API)  The AID helps programmers developing applications that functions consistently  Operating system fall into several groups, including single user, multitasking, and multiuser  UNIX is a powerful multiuser operating system that was invented in 1960  UNIX has a number of major benefits, and it provides modular tools  The Mac, as it came to be known, redefined computing  To develop the MAC, interaction with a computer was primary based on entering commands  DOS, short for Disk Operating System was invented in 1981, same with the IBM’s PC.  Also many different versions of DOS came out by different companies

 All of the work you do on the computer it involves software  Software can be divides into two groups: systems and applications  Operating systems also fall into this category  Application software serves almost every imaginable function from writing documents and s, spreadsheets, computer-aided drafting, animation, and games  Application software cannot run through operating systems  System Software is low-level software that interacts with the computer at a very basic level