CS 220 Computer Organization

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CS 220Computer Organization

• Chapter 1 Background and Introduction

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CS 220 Computer Organization Background and
Introduction

• Interface between hardware and software
• Abstraction
• Ex. Steering a Car
• Computer Science is riddled with abstractions
• Model an abstraction used to capture an
  important aspect of the system without all of the
  details that are irrelevant to that aspect
• Hierarchical Models A layered approach with
  various levels of abstraction

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CS 220 Computer Organization Background and
Introduction

• So why am I telling you all of this about
  abstractions?

Because we are going to be studying Computer
Organization, which is a highly complex topic.
Abstractions will be used constantly and details
will be filled in.
As a programmer, how do we talk to a computer?
Machine Language Sequences of Ones and Zeros
HLL Java, C, Fortran, Pascal
Assembly Language Program
Compiler
Assembler
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CS 220 Computer Organization Background and
Introduction

• Figure 1.2 (text p 5)
• 55
• 8b ec
• 83 ec 08
• 53
• 56
• 57
• c7 45 fc 14
• 0f 8f 12 00 00 00
• 8b 45 f8

Figure 1.3 (text p 6) push ebp mov ebp, esp sub
ebp, 8 push ebx push esi push edi mov dword ptr
_counterebp,1 mov dword ptr _squaresebp,0 cm
p dword ptr _counterebp, 20
Machine Code Assembly
Code
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CS 220 Computer Organization Background and
Introduction

• History of computer development
• Early computers had emphasis on hardware
• Software was programmed by plugging a set of
  relays into appropriate places
• Computers became faster with vacuum tubes, but
  the systems remained hardware intensive
• Stored memory save programs in memory for later
  use
• Memory was initially very small 1 Kbits
• Transistors smaller computers, reliable (mid
  1950s)

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CS 220 Computer Organization Background and
Introduction

• With the transistor came a greater focus on
  software
• High level languages and compilers came into
  existence
• Operating systems moved from batch processing to
  interactive
• Integrated circuits were developed, consisting of
  many transistors
• The processor now fit onto a single chip
• Intel iAPX Architecture, Pentium processor
• 8086 1978 Pentium - 1993
• 80286 1982 Pentium Pro - 1995
• 80386 1985 Pentium II - 1997
• 80486 1989 Pentium III, IV

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CS 220 Computer Organization Background and
Introduction

• History of Computing
• Two eras Pre-World War II and Post-World War
  II
• Calculation
• Abacus (BC)
• Pascaline (1642) Blaise Pascal, a mechanical
  adder
• Input and Programming
• Jacquards Loom (1801) punched cards
• Input, Calculation, Control, Storage, and Output
• The Difference Engine (1821) Charles Babbage
• The Analytical Engine any series of mathmatical
  instructions programmed into it. Programmer
  Lady Ada, Countess of Lovelace
• Data Input
• Punched card tabulating machine (1887) Herman
  Hollerith Electrical machine, using punched
  cards to tabulate the 1890 census

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CS 220 Computer Organization Background and
Introduction

• The Differential Analyzer (1932) Vannevar Bush
  (MIT) Mechanical device to solve calculus
  problems (mechanical, single purpose)
• ABC Atanasoff-Berry Computer (1939) solutions
  to linear equations First electronic digital
  computer used 300 vacuum tubes
• Mark I (1936-1944) Harvard University,
  electromechanical, paper tape instruction, 500
  miles of wire
• ENIAC (Electronic Numerical Integrator and
  Calculator) (1943-1946) Eckhart and Mauchly,
  University of Pennsylvania. 30 by 50, 30 tons,
  18000 tubes, programmed with wires
• EDVAC (Electronic Discrete Variable Automatic
  Computer) (1945-1946) John Von Neumann, Stored
  program concept with program and data together
  in memory, instructions executed sequentially
• UNIVAC (Universal Automatic Computer) First
  commercially sold (1951)
• 1947 Transistor was developed as Bell Labs

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CS 220 Computer Organization Background and
Introduction

• Mid 1960s, Integrated circuits were developed,
  embedding transistors onto a single chip of
  silicon
• 1971 VLSI (Very Large Scale Integration) The
  first microprocessors
• 1976 Steve Jobs and Steve Wozniak started Apple
  Computer, Inc.
• 1978 Intel 8086 microprocessor was introduced

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CS 220 Computer Organization Background and
Introduction
Four Generations

• Moores Law
• Speed of computation doubles every 12-18 months
• Size of memory doubles every 12-18 months
• Number of components on a chip doubles every
  12-18 months