(http://news.computercollector.com): It's nice to see Evan has mentioned this lovely Differential Analyser, and I am sorry I missed seeing it (thanks especially to Erik Klein for his nice photos of it, http://www.vintage-computer.com/vcf7.shtml, which first alerted me to its having been there). Many years ago (1980) I made myself a simple two-integrator Differential Analyser, which worked on exactly the same principle. I was inspired by the Meccano machine which was on display at the Museum of Transport and Technology in Auckland - this was one of a number of similar machines made in the '30s - and found a construction article in the Amateur Scientist column of Scientific American. I was wondering whether anyone here with '70s issues of SciAm might be able to make a copy, or at least give a definite date for it. It would have been in the early-to-mid '70s, certainly before '78. Thanks, and if anyone still hasn't seen Tim's machine, go to www.meccano.us and prepare to be amazed. (Sellam, give up on that TI thingy and go buy a Meccano set) -- Lawrence Wilkinson lawrence(a)ljw.me.uk Ph +44(0)1869-811059 http://www.ljw.me.uk