They also had difficulty to avail as they were machine language dependent. In this generation vacuum tubes were replaced by the transistors invented at bell laboratories. These machines were comparatively small in size when compared to the first generation machines. The computational speed was very high i. They were portable, reliable and not susceptible to the failures of hardware. They required manual assembling of components to form a functional unit and were assembly language dependent as compilers were developed to change from high-level language to assembly language program.
They were low in cost, magnetic ferrite core memories were used as main memory and magnetic tapes as secondary memory. Improvement of the individual input and output memories helped to operate in parallel with the CPU.
Like personal computers, most workstations are single-user computers. However, workstations are typically linked together to form a local-area network, although they can also be used as stand-alone systems. It could be a workstation or a personal computer. Personal computer: It can be defined as a small, relatively inexpensive computer designed for an individual user.
In price, personal computers range anywhere from a few hundred pounds to over five thousand pounds. All are based on the microprocessor technology that enables manufacturers to put an entire CPU on one chip. Businesses use personal computers for word processing, accounting, desktop publishing, and for running spreadsheet and database management applications.
At home, the most popular use for personal computers is for playing games and recently for surfing the Internet. Personal computers first appeared in the late s. One of the first and most popular personal computers was the Apple II, introduced in by Apple Computer. During the late s and early s, new models and competing operating systems seemed to appear daily. The IBM PC quickly became the personal computer of choice, and most other personal computer manufacturers fell by the wayside.
One of the few companies to survive IBM's onslaught was Apple Computer, which remains a major player in the personal computer marketplace. In recent years, the term PC has become more and more difficult to pin down. In general, though, it applies to any personal computer based on an Intel microprocessor, or on an Intel-compatible microprocessor. For nearly every other component, including the operating system, there are several options, all of which fall under the rubric of PC Today, the world of personal computers is basically divided between Apple Macintoshes and PCs.
The principal characteristics of personal computers are that they are single-user systems and are based on microprocessors.
However, although personal computers are designed as single-user systems, it is common to link them together to form a network. In terms of power, there is great variety. At the high end, the distinction between personal computers and workstations has faded.
The chassis or case is the metal frame that serves as the structural support for electronic components. Every computer system requires at least one chassis to house the circuit boards and wiring. The chassis also contains slots for expansion boards. If you want to insert more boards than there are slots, you will need an expansion chassis, which provides additional slots.
Then come the portable computers that are computers small enough to carry. Portable computers include notebook and subnotebook computers, hand-held computers, palmtops, and PDAs. Tower model The term refers to a computer in which the power supply, motherboard, and mass storage devices are stacked on top of each other in a cabinet.
This is in contrast to desktop models, in which these components are housed in a more compact box. The main advantage of tower models is that there are fewer space constraints, which makes installation of additional storage devices easier. Desktop model A computer designed to fit comfortably on top of a desk, typically with the monitor sitting on top of the computer. Desktop model computers are broad and low, whereas tower model computers are narrow and tall.
Because of their shape, desktop model computers are generally limited to three internal mass storage devices.
Desktop models designed to be very small are sometimes referred to as slim line models. Notebook computer An extremely lightweight personal computer. Notebook computers typically weigh less than 6 pounds and are small enough to fit easily in a briefcase. Aside from size, the principal difference between a notebook computer and a personal computer is the display screen. Notebook computers use a variety of techniques, known as flat-panel technologies, to produce a lightweight and non-bulky display screen.
The quality of notebook display screens varies considerably. In terms of computing power, modern notebook computers are nearly equivalent to personal computers.
They have the same CPUs, memory capacity, and disk drives. However, all this power in a small package is expensive. Notebook computers cost about twice as much as equivalent regular-sized computers. Notebook computers come with battery packs that enable you to run them without plugging them in. However, the batteries need to be recharged every few hours.
Laptop computer A small, portable computer -- small enough that it can sit on your lap. Nowadays, laptop computers are more frequently called notebook computers. Subnotebook computer A portable computer that is slightly lighter and smaller than a full-sized notebook computer. Typically, subnotebook computers have a smaller keyboard and screen, but are otherwise equivalent to notebook computers.
The most popular hand-held computers are those that are specifically designed to provide PIM personal information manager functions, such as a calendar and address book. Although computers are typically viewed as a modern invention involving electronics, computing predates the use of electrical devices.
The ancient abacus was perhaps the first digital computing device. Analog computing dates back several millennia as primitive computing devices were used as early as the ancient Greeks and Romans, the most known complex of which being the Antikythera mechanism. Later devices such as the castle clock , slide rule c. Telephone switching came to be based on this technology, which led to the development of machines that we would recognize as early computers.
The presentation of the Edison Effect in provided the theoretical background for electronic devices. Originally in the form of vacuum tubes, electronic components were rapidly integrated into electric devices, revolutionizing radio and later television.
It was in computers however, where the full impact of electronics was felt. With the invention of solid-state electronics, the transistor and ultimately the integrated circuit, computers would become much smaller and eventually affordable for the average consumer.
It was designed in early 17th Century. Herman Hollerith introduced the First electromechanical, punched-card Data-processing machine It was used to compile information for the U. This generation lasted until about the end of the 's although some stayed in operation much longer than that. The main defining feature of the first generation of computers was that vacuum tubes were used as internal computer components. Vacuum tubes are generally about centimeters in length and the large numbers of them required in computers resulted in huge and extremely expensive machines that often broke down as tubes failed.
Mauchly and. Presper Eckert, Jr. It used 18, vacuum tubes Punch-card input. Weighed thirty tons and occupied a thirty-by-fifty-foot space. Census processing started. Transistors were capable of performing many of the same tasks as vacuum tubes but were only a fraction of the size. The first transistor-based computer was produced in In comparison to the computers of the second generation, the size of the computers of the third generation was smaller. In comparison to the computers of the second generation, the computing time taken by the computers of the third generation was lesser.
The period to till date and beyond, roughly considered as the period of fifth generation of computers. By the time, the computer generation was being categorized on the basis of hardware only, but the fifth generation technology also included software. Working with computers of this generation was fast and multiple tasks could be performed simultaneously. Some of the popular advanced technologies of the fifth generation include Artificial intelligence, Quantum computation, Nanotechnology, Parallel processing, etc.
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