COAL Lesson 1

First Generation (1940-1956)

Vacuum Tubes

Second Generation (1956-1963)

Transistors

Third Generation (1964-1971)

Integrated Circuits

Fourth Generation (1971-Present)

Microprocessors

Fifth Generation (Present and Beyond)

Artificial Intelligence

First Generation (1940-1956) Vacuum Tubes

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, generated a lot of heat, which was often the cause of malfunctions.

Vacuum Tube

an electronic device that controls the flow of electrons in a vacuum. It used as a switch, amplifier, or display screen in many older model radios, televisions, computers, etc.

Transistor

an electronic component that can be used as an amplifier or as a switch. It is used to control the flow of electricity in radios, televisions, computers, etc.

Second Generation (1956-1963) Transistors

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.

Integrated Circuit

a small electronic circuit printed on a chip (usually made of silicon) that contains many its own circuit elements (e.g. transistors, diode, resistors, etc.).

Third Generation (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.

Fourth Generation (1971-Present) Microprocessors

The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. 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.

Microprocessor

an electronic component held on an integrated circuit that contains a computer’s central processing unit (CPU) and other associated circuits.

Fifth Generation (Present and Beyond) Artificial Intelligence

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.

Artificial intelligence (AI)

an area of computer science that deals with the simulation and creation of intelligent machines or intelligent behave in computers (they think, learn, work, and react like humans).

Artificial Intelligence

Which technology is used in 5th generation computers?

Components of a Computer

They are five classic components of a computer. The operation of the processor is best understood in terms of these components.

Input

external devices such as keyboards, mice, disks, and networks that provide input to the processor.

Memory

holds instructions and most of the data for currently executing programs.

Datapath

manipulates the data coming through the processor. It also provides a small amount of temporary data storage.

Control

generates control signals that direct the operation of memory and the datapath.

Output

external devices such as displays, printers, disks, and networks that receive data from the processor.

Von-Neumann Model

proposed his computer architecture design in 1945 which was later known as Von-Neumann Architecture. It consisted of a Control Unit, Arithmetic, and Logical Memory Unit (ALU), Registers and Inputs/Outputs.

Von Neumann architecture

s based on the stored-program computer concept, where instruction data and program data are stored in the same memory. This design is still used in most computers produced today.

A Von Neumann-based computer

Uses a single processor; Uses one memory for both instructions and data; Executes programs following the fetch-decode-execute cycle

Central Processing Unit (CPU)

It can also be defined as an electric circuit responsible for executing the instructions of a computer program.

Control Unit

consists of a program counter that contains the address of the instructions to be fetched and an instruction register into which instructions are fetched from memory for execution.

Arithmetic and Logic Unit (ALU)

performs the required micro-operations for executing the instructions.

Registers

refer to high-speed storage areas in the CPU. The data processed by the CPU are fetched from this

Memory Unit

is a collection of storage cells together with associated circuits needed to transfer information in and out of the storage.

Words

The memory stores binary information in groups of bits called

Memory Address Register

a CPU register that holds the physical memory address from which data or instructions will be fetched, or to which data will be written

Memory Data Register

is a high-speed register in a computer's Central Processing Unit (CPU) that temporarily holds the actual data being transferred to or from main memory (RAM)

Accumulator

a special-purpose processor register inside a CPU's arithmetic logic unit (ALU) that temporarily stores the intermediate results of arithmetic and logical operations

Program Counter

a special register inside a computer's central processing unit (CPU) that holds the memory address of the next instruction to be fetched and executed

Current Instruction Register

a special-purpose CPU register that holds the instruction currently being decoded, analyzed, or executed