Wednesday, September 3, 2008

Lecture 1

    • Email protocol
      • From your York computer science student account
      • Subject line cs2021A......
      • Identify yourself in the email by name and student number
    • Office hours
      • CSE3012
        • Monday and Wednesday 1-2pm
    • Phone
      • 416 736 2100
    • Course webpage
    • Grade Weighting
      • 24% - LABS
      • 26% - MIDTERM
      • 50% - FINAL EXAM


 


 

Lecture 1

  • What is a computer?
    • Components
      • Input (mouse, keyboard)
      • Output (display, printer)
      • Memory (disc drives, DRAM, SRAM, CD)
      • Processor
      • Network
  • Technology
    • Processor
      • Logic capacity
        • About 30% per year
      • Clock rate
        • About 20% per year
    • Memory
      • DRAM capacity
        • About 60% per year
      • Memory speed
        • About 10% per year
      • Cost per bit
        • Decreases about 25% per year
    • Disk
      • Capacity
        • ~60% per year
  • Rapidly changing field
    • In order
      • Vacuum tube
      • Transistor
      • IC
      • VLSI
    • Doubling every 1.5 years
      • Memory capacity
        • Ram has grown by 100,000x in 44 years
        • Memory capacity has grown exponentially as a trend
        • Random note: 1GB = 1,073,741,824 bytes
      • Processor speed
        • This is due to advances in technology and organization
        • Processor performance has grown exponentially as a trend
        • Moore's law
          • 2x transistors/chip every 1.5 years
  • Machine language
    • Electronic circuits recognize and execute
      • A limited set of instructions
      • Keep limited and simple to reduce cost and complexity
      • Hard for humans to understand
      • Is in raw digital form
        • Binary digits (0 , 1)
    • Book of instructions
      • 001100 – Store
      • 001110 – Add
      • 111000 – Subtract
      • 101000 - Load
      • This is just an example for a theoretical machine
  • Design Forms
    • Build what we can
      • Implies language
      • Therefore: Machine implies Language


         

    • Decide what we want to do by what we build
      • Implies Machine
      • Therefore: Language implies Machine
      • All programs translate into this set first
      • Designers must decide on the instruction set
    • Translation comes in two forms:
      • Compilation
        • Replace each statement in L2 (L2 is the language built on top of L1 to make it more understandable by humans)
        • At end have program in L1
        • Execute this level L1 set of statements
        • Program in L2 -> compiler -> program in L1
      • Interpretation
        • write program in L1 language that will take as input a program in L2
        • each statement in L2 is translated to L1 statements and executed immediately

Program in L2 -> statement in L2 -> interpreter -> statement in L1 -> go to next statement in L2

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