Lecture Notes for Operating Systems

5 September 2001 - Introduction

  1. start with hardware

    1. cpu, memory, bus

    2. connect to the outside world - io devices

      1. work the device - data independent

      2. perform repetitive tasks - load programs into memory

    3. hardware is expensive and slow - share the costs among lots of programs

      1. one run program while another's waiting

      2. how to do that, what does that

    4. keep the programs separate

  2. the three os themes - economy, protection, convenience

    1. economy - efficiently manage resources; expensive (user time) or limited (handheld power) or both (wireless transmission bandwidth)

    2. protection - levels of protection, protection against various levels of malevolence

    3. convenience - define useful abstractions

    4. pick any one

  3. different choices lead to different operating systems

    1. batch - expensive machines; huge jobs

    2. timesharing - convenience; interactive jobs

    3. single user - cheap machines; no protection; not as helpful as it seems

    4. real-time - highly efficient; critical jobs

  4. but aren't operating systems a done deal

    1. i don't know - ask the dept. of justice.

    2. automotive electronics

      1. chassis control, engine control, automatic transmission, ABS/ASR, cruise control

      2. cabin comfort, air conditioning, dashboard, trip computer, display range, radio, telephone, navigation

      3. intelligent switching, anti-finger traps, power seats, alarms

      4. cpus - 32 bits power train; 16 bits vehicle control, 8 bits body control and driver information; 4 bits, dashboard

      5. now, network them together, multiplex them, link them up to the external environment

This page last modified on 10 September 2001.