¢ 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=¢¢¢¢
