Museum of Science and Industry (was: Interesting places in Chicago area?)

Don't forget the U-505's computer... => -----Original Message----- => From: owner-classiccmp(a)classiccmp.org => there, two of the exhibits I still recall and are more on topic as they => relate to computers. => => One exhibit was a little display about the size of a podium. It had an => exposed PC board on top with heavy gauge copper in an odd => pattern. A metal => "pen" was used to draw a digit from 0 to 9, and based on which => traces you => touched and the sequence you touched them in, it would display => what digit => you had written. On the front was the schematic of the thing, => containing => many dozens of transistors. Was it the first palm pilot? This was => probably around 1974 or so. => => The other display I recall vividly was the tic-tac-toe machine => implemented => as a clacking relay computer. You could see the relays => activating behind => the plexiglass. In 8th grade when I understood just the basics => of digital => logic I attempted to design my own tic-tac-toe computer using => transistor/diode/resistor logic. I didn't understand how => "state" worked, => so I had a massive tangle of combinational logic. I probably would have => had to feed 100V in to the inputs to get a measurable output => after so many => diode drops. In high school, I had access to a Wang 2200 computer, and => after a few warm up programs, I wrote a BASIC program to play tic tac => toe. My first implementation was along the lines of the combinational => logic -- just a lot of straight "if this and this and this then do that" => statements. => => I visited there about five years ago and it didn't hold the same => appeal. I => don't know if it was just that I had matured and the wonder of the world => has been lost, or if the displays just have a different flavor now that => doesn't appeal to me. => => Ah, memories. => => ----- => Jim Battle == frustum(a)pacbell.net => =>