Almost everything in our modern lives seems like it’s digital, which we think of as electronics. But the definition of digital doesn’t require something to be electrical, as something being digital means that it is a piece of information in a format that has a non-ambiguous interpretation. The most simple example of this is in how the Jacquard Loom functioned, with holes in paper cards which allowed certain colors of thread to pass through, and depending on where the holes were, the loom could effortlessly produce countless patterns of woven fabric. The first electronic computers to exist also used these punch-card formats of conveying information in a digital format, where each card represented a line of code, and holes in the card in specific columns would signify corresponding characters in the code by shining light at the card, and the signal that would return, which is a digital signal, given that it has only two concrete possibilities, would determine the character, based on if light was allowed to pass through (a hole) or not, (no hole). I read through multiple articles on the computer punch card system, but none of them* said how the computers determined what was a hole or not, but I found a Reddit post, I know not the best source, that it was a beam of light which gave the computer the ability to tell if there was a hole at a particular spot in the card or not. A benefit of computers being able to process information, reflective of the loom’s advantage, is the significantly increased speed at which information could be processed, while a downside of the computer punch card system is it’s physical limitations on data storage, as one card could only contain one line of code.Â
*Sites that didn’t explain how the computers could tell a hole vs. no hole that I looked at:
https://www.ibm.com/history/punched-card
https://www.si.edu/spotlight/punch-cards/punch-cards-data-processing
Learning objective:Â
- Explain the essence of what it means to be digital