Computer Architecture and Organization Lecture Notes PDF

Course: Computer Architecture and Organization Book: Computer organization and architecture designing for th performance 8 edition  LECTURE-2 COURSE INSTRUCTOR: SHAHID KHAN Assistant P...

Course: Computer Architecture and Organization Book: Computer organization and architecture designing for th performance 8 edition  LECTURE-2 COURSE INSTRUCTOR: SHAHID KHAN Assistant Professor in Computer Science ([email protected])  2.1 A BRIEF HISTORY OF COMPUTERS The First Generation: Vacuum Tubes ENIAC (1946-1955): The ENIAC (Electronic Numerical Integrator And Computer), designed and constructed at the University of Pennsylvania, was the world’s first general purpose electronic digital computer. Vacuum tube- Reading https://www.pbs.org/transistor/science/events/vacuumt.html  2.1 A BRIEF HISTORY OF COMPUTERS The First Generation: Vacuum Tubes ENIAC (1946-1955) Contd.: Features of ENIAC: It was enormous, weighing 30 tons, occupying 1500 sq. ft space, and containing more than 18,000 vacuum tubes. It consumed 140 kilowatts of power during operations and was capable of 5000 additions/sec. It was a decimal system with memory of 20 accumulators, each capable of holding a 10-digit decimal number. A ring of 10 vacuum tubes represented each digit. At any time, only one vacuum tube was in the ON state, representing one digit.  2.1 A BRIEF HISTORY OF COMPUTERS The First Generation: Vacuum Tubes ENIAC (1946-1955) Contd.: The major drawback of the ENIAC was that it had to be programmed manually by setting switches and plugging and unplugging cables.  2.1 A BRIEF HISTORY OF COMPUTERS The First Generation: Vacuum Tubes THE VON NEUMANN MACHINE (1946-1952): It worked on the stored-program concept, designed in 1946 by Von Neumann and his colleagues at the Princeton Institute for Advanced Studies (IAS), referred to as the IAS computer. Figure 2.1 shows the general structure of the IAS computer (compare to middle portion of Figure 1.4). It consists of: A main memory, which stores both data and instructions1 An arithmetic and logic unit (ALU) capable of operating on binary data  2.1 A BRIEF HISTORY OF COMPUTERS The First Generation: Vacuum Tubes THE VON NEUMANN MACHINE- Structure  2.1 A BRIEF HISTORY OF COMPUTERS The First Generation: Vacuum Tubes THE VON NEUMANN MACHINE- Features: Its memory consists of 1000 storage locations, called words, of 40 binary digits (bits) each for storing data and instructions. Numbers represented as a binary code i.e. a sign bit & a 39-bit value. A word may also contain two 20-bit instructions i.e. each instruction consisting of an 8-bit operation code (opcode) and a 12-bit address designating one of the words in memory (numbered from 0 to 999).  2.1 A BRIEF HISTORY OF COMPUTERS The control unit operates the IAS by fetching instructions from memory and executing them one at a time. 2.1 A BRIEF HISTORY OF COMPUTERS The Von Neumann machine- extended structure  2.1 A BRIEF HISTORY OF COMPUTERS The Second Generation-Transistors: The first major change is the replacement of the vacuum tube by the transistor in 1950 Bell Labs. The transistor is smaller, cheaper, and dissipates less heat than a vacuum tube but can be used in the same way as a vacuum tube to construct computers. The transistor is a solid-state device, made from silicon. This remarkable change was brought by NCR (Currently NCR Atleos), RCA (Radio Corporation of America) and IBM. 2.1 A BRIEF HISTORY OF COMPUTERS  2.1 A BRIEF HISTORY OF COMPUTERS The Third Generation: Integrated Circuits (1950s and early 1960s) A single, self-contained transistor is called a discrete components—transistors, resistors, capacitors, and so on were manufactured separately, packaged in their own containers, and soldered or wired together onto a circuit boards, which were then installed in computers and other electronic equipment. The entire manufacturing process, from transistor to circuit board, was expensive and cumbersome. In 1958 came the achievement that revolutionized electronics and started the era of microelectronics: the invention of the integrated circuit (ICs) that defines the third generation of computers.  2.1 A BRIEF HISTORY OF COMPUTERS MICROPROCESSORS: A breakthrough was achieved in 1971, when Intel developed its 4004.The 4004 was the first chip to contain all of the components of a CPU on a single chip; The microprocessor was born. The 4004 can add two 4-bit numbers and can multiply only by repeated addition. By today’s standards, the 4004 is hopelessly primitive, but it marked the beginning of a continuing evolution of microprocessor capability and power.  2.1 A BRIEF HISTORY OF COMPUTERS MICROPROCESSORS (contd.): This evolution can be seen most easily as: - in the number of bits that the processor deals with at a time, i.e. the concept of data bus width: the number of bits of data that can be brought into or sent out of the processor at a time. - the number of bits in the accumulator or in the set of general- purpose registers. Often, these measures coincide, but not always.  2.1 A BRIEF HISTORY OF COMPUTERS MICROPROCESSORS (contd.): For example, a number of microprocessors were developed that operate on 16-bit numbers in registers but can only read and write 8 bits at a time. The next major step in the evolution of the microprocessor was the introduction in 1972 of the Intel 8008. This was the first 8-bit microprocessor. 2.1 A BRIEF HISTORY OF COMPUTERS 2.1 A BRIEF HISTORY OF COMPUTERS