Timeline for Were punching tools for punch cards with rectangular holes easier to keep sharp than those for round holes?
Current License: CC BY-SA 4.0
19 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 23, 2023 at 13:36 | comment | added | UncleBod | @Coder I didn't say it was. I said it was used for tapes (paper and polymere). And I can assure you, it was a very large amount of tapes that were punched through the years. | |
| Aug 23, 2023 at 12:59 | comment | added | Coder | @UncleBod ASCII wasn't introduced for punch cards, "modern" punch cards used mainly EBCDIC. ASCII was invented to have a interchangeable coding format between computers and printers. If you watch the other video of that channel about punch cards you will even hear, that ASCII is not used for punch cards, because too many holes would have weakened the card, thus ASCII is not practical for punch cards and therefore was not used for punch cards. | |
| Aug 23, 2023 at 12:27 | comment | added | UncleBod | @Coder If wear was a significant problem, as you claim, why did they later introduce 7 bit ASCII with parity bit, that would result in more wear? As I understand the video, the Murray code was the second code ever used, and probably the first used in automatic machines. The Murray code might have bben as early as from 1901. | |
| Aug 23, 2023 at 11:47 | comment | added | Coder | @UncleBod The problem was big enough to create an encoding system in which characters that occur very frequently have as few holes as possible. If wear and tear hadn't played a significant role, as you claim, this effort would not have been made. You can also very well assume that people thought a lot about it at the time and recognized this as a major problem, for which they then saw this coding as a solution to alleviate this problem. | |
| Aug 23, 2023 at 10:52 | comment | added | UncleBod | @Coder Even if tehre is wear on the punch every time you use it, (everyone working in metal preparation knows that) it doesn't mean it will be a problem during the lifetime of the machine, or that you need to chenge the format of the holes, or that changing teh foramt of the holes will make things better. The lifetime of the punch is given more from the material used in the punch and the possible after treatment (hardening, tempering etc). Nothing in the video gives any indication of teh actual lifetiem of teh punches in "mean number of holes punched between faliures". | |
| Aug 23, 2023 at 6:55 | comment | added | Coder | @UncleBod You should listen more carefully to the video. The proof is clear in the video. He said in the second sentence: "Every time you punch one of these big holes it wears out that hole punch on your machine." "Hole punch" means the tool. | |
| Aug 21, 2023 at 7:18 | comment | added | UncleBod | @Coder No, the video says that "He said 'Look, if we are going to be punching holes coresponding to characters ...' ". He was (right or wrong) making an assumption from what he knew, but the video says nothing about anyone proving that the wear on the punches would be, or ever was, a problem. BTW, punched paper (and plymere) tapes were used paralell to punchcards, so the division was only that some media used round holes and some media used rectangual holes. (Might very well have been obscure uses of other hole types also). | |
| Aug 20, 2023 at 23:11 | comment | added | Coder | @UncleBod They adjusted the code to the need. That should be more than necessary to have a proof. | |
| Aug 20, 2023 at 17:01 | comment | added | Weather Vane | A square hole allows greater tolerance in the positioning. With a circular hole, a small error in the lateral position means that the longitudinal size of the hole reduces, while with a rectangular hole there is no loss in longitudinal accuracy if the lateral postioning is less than perfect. | |
| Aug 20, 2023 at 15:34 | comment | added | UncleBod | Where is the proof in that video? That one peroson long ago (before they started to punch codes on paper tape) said that this is what will happen is not a proof. A proof is if someone can give a figure of how often they had to change/sharpen the punches. | |
| Aug 20, 2023 at 11:49 | history | became hot network question | |||
| Aug 20, 2023 at 3:26 | history | edited | Coder | CC BY-SA 4.0 | additional information |
| Aug 20, 2023 at 1:39 | comment | added | Raffzahn | @Coder Going from 40 to 80 cold be implemented for most parts with minor adjustment, like halving transport speed, the 'only' change being a wider data area in one card (which meant doubling processing capacity) but no principal change. Think of it like going from single sided disketes to double sided :)) | |
| Aug 20, 2023 at 1:36 | comment | added | Raffzahn | @Coder staggering wasn't a solution. Going from 40 to 80 holes per row was already increasing the character rate more than mechanical devices could handle. Remember the punch card was defined and implemented at a time when there was no fast (not even slow) electronics. In addition staggering would have meant to double the needed amount of mechanical contacts wich in turn needed to be operated in an alternating pattern. A rather unwelcome complication. Not to mention that all tools (key punch) would have to operate on alternating height when creating/editing. | |
| Aug 20, 2023 at 1:31 | comment | added | Raffzahn | @another-dave It's competition. The highest packaging without changing the width is reached by round (or square) holes. Rectangular are sub optimal. In the end, the rectangular form only came due IBM keeping the vertical spacing as with the old cards but reducing the horizontal spacing to get 80 on the same card size. It would have been logical to go to round (or square) and either add more rows or more space inbetween. Not doing so was not driven by physics or technology. | |
| Aug 20, 2023 at 1:26 | answer | added | Raffzahn | timeline score: 9 | |
| Aug 20, 2023 at 1:20 | comment | added | Coder | I doubt it, because if you make smaller round holes, you get the same density. And if you stagger the rows, you can increase the storage density with holes much more than with rectangles. | |
| Aug 20, 2023 at 1:16 | comment | added | dave | I understand that the rationale for rectangular holes is closer packing, i.e., more data per square inch. As in this IBM history. | |
| Aug 20, 2023 at 0:20 | history | asked | Coder | CC BY-SA 4.0 |