>>> How many computer users nowadays have ever seen or used >>> a punch card? I have a couple in a box as souvenirs. >>> That 72 is especially bizarre. How many people these days >>> could even tell you where that strange number comes from? >> >But lots of software does it. >> I used the columns after 72 for sequence numbers so I could >> use the sorter to put a deck of cards back in order if (when) >> I dropped them. > I wasn't for when YOU dropped them so much as when the computer ops > dropped them (and didn't tell you). Particularly BEFORE the run! > That was why we put big diagonal lines in felt pen across the tops.
I discovered the point of that the hard way when I wrote a program to analyze an undergraduate physics experiment, Cavendish's method for determining the gravitational constant. You set two small lead balls oscillating between two large lead balls; most of the damping is due to air friction but a second-order factor is due to gravity. Most students did it graphically on paper. I decided to do better, found our local numerical analysis guru, got a state-of-the-art algorithm for estimating the parameters of damped harmonic motion, and coded it in Fortran IV for an IBM 1130. Everything hunky-dory except I dropped part of my data deck and inadvertently produced an oscillatory motion with a huge jag in it. My resulting estimate for the strength of gravity made it comparable with the nuclear strong force. No time to book another run after I figured out what happened. The odd thing is, here am I, more than 30 years on, sitting at a Power Mac 9600/200 with 384Mb of memory - whereas the 1130 had 32Kb, I think, and presumably ran at a few thousand instructions per second - but despite having a few gigabytes of software under the table I couldn't do the same analysis now. I couldn't have imagined there'd ever be a computer you couldn't run Fortran on. ----------------------------------------------------------------------------- Jack Campin: 11 Third Street, Newtongrange, Midlothian EH22 4PU; 0131 6604760 <http://www.purr.demon.co.uk/jack> * food intolerance data & recipes, Mac logic fonts, Scots traditional music files, and my CD-ROM "Embro, Embro". ------> off-list mail to "j-c" rather than "abc" at this site, please <------ To subscribe/unsubscribe, point your browser to: http://www.tullochgorm.com/lists.html
