Weekly Classic Computer Trivia Question (20141215)

Thanks for playing everyone. The answer I was looking for was vertical displacement of the letters or wavy text. There are two reasons this happened. The primary reason is the critical timing of the firing of the hammer. The other reason would affect all types of impact printers and that is stopping the paper motion through the printer. This was not usually a problem unless the weight of the paper was very light which would allow the sprocket holes to elongate. This would allow the paper to continue moving around while the drum was completing its turn. The sprocket holes could also elongate if the paper tension was increased too much. None of this was of much concern on the slower 300 lpm printers but at 1000 lpm or faster timing would be more than three times as critical. Chain, train, and band printers would tend to have mild misalignment in the horizontal direction but could still have vertical alignment issues if the paper continued to move around. One of my friends reminded me of the most unusual uses of the 1000 LPM printer on the CDC 3400 that South Dakota School of Mines and Technology had in the 1970's and that was as a bass drum when the computer played the Stars and Stripes forever. I only saw this run a handful of times and it is probably one of those things lost forever. Even if someone had a copy of the program no simulator would be accurate enough to run it and I am pretty sure there is no running hardware. Doug Ingraham On Mon, Dec 15, 2014 at 2:07 PM, Doug Ingraham <dpi at dustyoldcomputers.com> wrote: