›               o=o=o=o=o=››       All I Know About Computers›         I Learned From My Mom›› This article comes from the  November› 1998  issue  of the JACG Newsletter. › It was submitted by DAVE GOODWIN.›› For years I badgered my  mother  with› questions  about  whether Santa Claus› is a real person or not.  Her  answer› was  always,  "Well...  you asked for› the presents and  they  came,  didn't› they?"  I finally understood the full› meaning of her reply when I heard the› definition  of  a  virtual device: "A› software  or  hardware  entity  which› responds  to  commands  in  a  manner› indistinguishable   from   the   real› device."   Mother was telling me that› Santa   Claus   is   avertual  person› (simulated  by  loving  parents)  who› responds to requests from children in› a  manner  indistinguishable from the› real saint.›› Mother      also      taught      the› IF...THEN...ELSE structure: "If  it's› snowing,  then  put  your  boots   on› before  you  go  to school; otherwise› just wear your shoes."›› Mother   explained   the   difference› between    batch    and   transaction› processing:  "We'll  wash  the  white› clothes when we get enough of them to› make  a  load,  but  we'll wash these› socks out right now by  hand  because› you'll need them this afternoon."›› Mother  taught me about linked lists.› Once, for a birthday party, she  laid› out  a  treasure  hunt  of ten hidden› clues, with each clue  telling  where› to  find  the  next one, the last one› leading to  the  treasure.  She  then› gave us the first clue.›› Mother    understood   about   parity› errors. When she counted socks  after› doing  the  laundry,  she expected to› find an even number and groaned  when› only  one sock of a pair emerged from› the   washing   machine.   Later  she› applied the principles of  redundancy› engineering to this problem by buying› our socks three identical pairs at  a› time.   This  greatly  increased  the› odds of being able to come up with at› least one matching pair.›› Mother had all of us  children  write› Christmas    thank   you   notes   to› Grandmother, one after another, on  a› single  sheet of paper which was then› mailed in a single  envelope  with  a› single  stamp.  This was obviously an› instance of blocking records in order› to  save money by reducing the number› of physical I/O operations.›› Mother used flags to help her  manage› the  housework.   Whenever she turned› on the stove, she put a potholder  on› top of her purse to remind herself to› turn it off again before leaving  the› house.›› Mother  knew abut devices which raise› an interrupt signal  to  be  serviced› when    they   have   completed   any› operation.    She   had  a  whistling› teakettle.›› Mother understud about LIFO ordering.› In my lunch bag she put the desert on› the   bottom,  the  sandwich  in  the› middle, and the napkin on top so that› things  would  come  out in the right› order at lunchtime.›› There is an old story that  God  knew› He  couldn't  be  physically  present› everywhere  at once, to show His love› for His people,  and  so  He  created› mothers.   That  is  the   difference› between  centralized  and distributed› processing.  As any  kid  who's  ever› misbehaved  at  a  neighbor's   house› finds  out,  all  the  mothers in the› neighborhood  talk  to  each  other. › That's   a   local  area  network  of› distributed processors that can't  be› beat.››    Mom, you were the best computer›          teacher I ever had.››               o=o=o=o=o=››››