Unit 1.01

CPU

"Brain of the computer"

2nd Generation Computers

(1956-1963) Transistors Transistors replace vacuum tubes and ushered in the second generation of computers. The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output. Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology.

3rd Generation Computers

1964-1971) Integrated Circuits The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers. Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors.

4th Generation Computers

1971-Present) Microprocessors The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the components of the computer—from the central processing unit and memory to input/output controls—on a single chip.

Mechanical Devices

A mechanical computer is built from mechanical components such as levers and gears, rather than electronic components. The most common examples are adding machines and mechanical counters, which use the turning of gears to increment output displays. Ex:Pascaline (1642), Difference Machine (1822),Analytical Machine, (1833)

Computer

An electronic machine that accepts data, processes it according to instructions, and provides the results as new data.

Components of a computer

CPU/Processor Memory (RAM) Storage Input Devices Output Devices

5th Generation

Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.

RAM

RAM holds data for all applications that are currently running on your computer, but only while the power is on.

Ada Byron

Sponsor of Analytical Machine.One of first people to realize its power and significance. Often called the first programmer because she wrote a program based on the design of the Analytical Machine.

Mark 1

The IBM Automatic Sequence Controlled Calculator (ASCC), called Mark I by Harvard University's staff,[1] was a general purpose electro-mechanical computer that was used in the war effort during the last part of World War II. One of the first programs to run on the Mark I was initiated on 29 March 1944 by John von Neumann, who worked on the Manhattan project at the time, and needed to determine whether implosion was a viable choice to detonate the atomic bomb that would be used a year later. The Mark I also computed and printed mathematical tables, which had been the initial goal of British inventor Charles Babbage for his "analytical engine".

First generation Computers

The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. They were very expensive to operate and in addition to using a great deal of electricity, the first computers generated a lot of heat, which was often the cause of malfunctions. First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time, and it could take days or weeks to set-up a new problem. Input was based on punched cards and paper tape, and output was displayed on printouts.

Electro-Mechanical Devices

These devices were not mass produced. Not Reliable, Still took time. Hollerith's machine took 6 years for a general account. Mark 1 - 51 ft. long, weighed 5 tons