This morning I sat down at my desk and looked over at my picture frame. When I was in Georgetown this summer, I took a picture of the plaque that adorns the building where Herman Hollerith invented and perfected the punched card machine. This is one of the pictures that, along with family pictures, macro pictures and nature pictures cycles through the day. But for some reason, this morning I thought about the Hollerith card.
Did I remember the coding scheme used by the card? A quick Google search confirmed my memories that it was a two-zone system, with 3 punch rows in zone 1 and 9 punch rows in zone 2 (although I recalled 3/10). This gives us 40 possible values per column, with 80 columns available. But then I had this thought, which I am sure others thought of before me.. The possible values per column is actually much more. By allowing multiple punches per zone, the card could be made to handle 2^12, or 4096 possible values, by ignoring the zoning of the card, and utilizing each potential hole as a bit value. And that's only with the same hardware. Because there was space between zone 1 and zone 2, the potential for more holes is there in the card, and with a bit more machining, another hole would be possible (although this thought process also gets into the potential for phase shifting along both x and y axis, giving us much more potential).
Just some geek thoughts for the morning.....completely unimportant.