5 ms·

It's humbling to thing that today, doing the same thing (if for some reason we'd like to use punched cards) we'd do the same thing with a $10 camera, a $35 Rasp

by ivoras 9y ago

It's humbling to thing that today, doing the same thing (if for some reason we'd like to use punched cards) we'd do the same thing with a $10 camera, a $35 Raspberry Pi and some trivial OCR-like software. Heck, even an ESP8266 could process images that simple.

maxerickson 9y ago
The machine in the article does 13 cards per second. A cobbled together OCR machine probably isn't going to match that.
- slantyyz 9y ago
  You could probably get something like a 10+ year old document scanner like a Scansnap 500 cheap. Those can hit 18ppm. edit: I realize this isn't 13pps, but it's not bad.
  - kalleboo 9y ago
    Any old 1080p video sensor will do 60fps
    - slantyyz 9y ago
      Yes, but I'm guessing the reliable mechanical feeding of the cards is the harder task than the actual image capture.
- kens 9y ago
  Exactly! Being able to reliably read 13 cards a second from a stack is quite a feat, requiring precision components such as picker knives and jogglers moving at high speeds. (I am not making up the joggler; it uh joggles cards into alignment.) Optical reading would avoid the metal brushes, which get out of alignment or make intermittent contact, but that's not the hard part. Yesterday's "Why Paper Jams Persist" in the New Yorker is also relevant, a look at why its difficult to move paper through a printer reliably. Punch cards, being made of paper, have the same problems but worse - they are weakened by the holes, and mistreated by the public. (Older readers may recall "Do not fold, spindle or mutilate" printed on punch card utility bills and such.) https://www.newyorker.com/magazine/2018/02/12/why-paper-jams-persist https://www.newyorker.com/magazine/2018/02/12/why-paper-jams...
  - DrScump 9y ago
    reliably read 13 cards a second ... and with considerable tolerance for bent or frayed cards. As late as the late 80s, Lockheed used IBM cards for time cards (for everyone, hourly or salaried). Lots of handling, lots of abuse, yet over 99% read ok on first try. That's over 14,000 in one job (program) every week for years on end.
- jandrese 9y ago
  The majority of the machine seems to be the heavily engineered card feeder with sensors on every conceivable point of failure. That would still be a hard problem today, especially if you're asking it to read ancient and potentially damaged cards.
slantyyz 9y ago
In 1985, my high school inherited an old PDP mini computer and we had to use optical cards to write BASIC programs in my Data Processing class. It was kind of a trip, since most of the computer nerds had Apples, Commodores or whatnot at home. The code and debug cycle was to mark your cards with a Sharpie, run them in the card reader, and then look at the printed output for bugs. If you were unlucky enough to have bugs AND drop your cards on the floor (I remember it happening to a couple of people in my class), you had to waste a bunch of time re-sorting your cards before you made the trip back to the card reader. Good times.
- mwcremer 9y ago
  Hence columns 73-80 being used for a sequence number.
  - kens 9y ago
    There's interesting history behind why columns 73-80 were used for a sequence number. FORTRAN was developed on the IBM 704, which was a 36-bit machine. The hardware read punch cards "sideways", storing each row of the card in two words. The consequence was that you could only read 72 columns of a card. That left columns 73-80 unusable for programming. But if you punched a sequence number in these columns, a dropped deck could be easily sorted by a high-speed card sorter. Card sorters were an interesting technology, going back to the 1920s, way before computers. They sorted cards on one column at a time using radix sort, and were electro-mechanical. I wrote about them here: http://www.righto.com/2016/05/inside-card-sorters-1920s-data.html http://www.righto.com/2016/05/inside-card-sorters-1920s-data...
    - WalterBright 9y ago
      > But if you punched a sequence number in these columns, a dropped deck could be easily sorted by a high-speed card sorter. I suppose heaven help you if you wanted to insert a statement between cards 37 and 38 :-)
      - 9y ago

by ivoras 9y ago

maxerickson 9y ago

The machine in the article does 13 cards per second. A cobbled together OCR machine probably isn't going to match that.

slantyyz 9y ago
You could probably get something like a 10+ year old document scanner like a Scansnap 500 cheap. Those can hit 18ppm. edit: I realize this isn't 13pps, but it's not bad.
- kalleboo 9y ago
  Any old 1080p video sensor will do 60fps
  - slantyyz 9y ago
    Yes, but I'm guessing the reliable mechanical feeding of the cards is the harder task than the actual image capture.
kens 9y ago
Exactly! Being able to reliably read 13 cards a second from a stack is quite a feat, requiring precision components such as picker knives and jogglers moving at high speeds. (I am not making up the joggler; it uh joggles cards into alignment.) Optical reading would avoid the metal brushes, which get out of alignment or make intermittent contact, but that's not the hard part. Yesterday's "Why Paper Jams Persist" in the New Yorker is also relevant, a look at why its difficult to move paper through a printer reliably. Punch cards, being made of paper, have the same problems but worse - they are weakened by the holes, and mistreated by the public. (Older readers may recall "Do not fold, spindle or mutilate" printed on punch card utility bills and such.) https://www.newyorker.com/magazine/2018/02/12/why-paper-jams-persist https://www.newyorker.com/magazine/2018/02/12/why-paper-jams...
- DrScump 9y ago
  reliably read 13 cards a second ... and with considerable tolerance for bent or frayed cards. As late as the late 80s, Lockheed used IBM cards for time cards (for everyone, hourly or salaried). Lots of handling, lots of abuse, yet over 99% read ok on first try. That's over 14,000 in one job (program) every week for years on end.
jandrese 9y ago
The majority of the machine seems to be the heavily engineered card feeder with sensors on every conceivable point of failure. That would still be a hard problem today, especially if you're asking it to read ancient and potentially damaged cards.

slantyyz 9y ago

In 1985, my high school inherited an old PDP mini computer and we had to use optical cards to write BASIC programs in my Data Processing class. It was kind of a trip, since most of the computer nerds had Apples, Commodores or whatnot at home. The code and debug cycle was to mark your cards with a Sharpie, run them in the card reader, and then look at the printed output for bugs. If you were unlucky enough to have bugs AND drop your cards on the floor (I remember it happening to a couple of people in my class), you had to waste a bunch of time re-sorting your cards before you made the trip back to the card reader. Good times.

mwcremer 9y ago
Hence columns 73-80 being used for a sequence number.
- kens 9y ago
  There's interesting history behind why columns 73-80 were used for a sequence number. FORTRAN was developed on the IBM 704, which was a 36-bit machine. The hardware read punch cards "sideways", storing each row of the card in two words. The consequence was that you could only read 72 columns of a card. That left columns 73-80 unusable for programming. But if you punched a sequence number in these columns, a dropped deck could be easily sorted by a high-speed card sorter. Card sorters were an interesting technology, going back to the 1920s, way before computers. They sorted cards on one column at a time using radix sort, and were electro-mechanical. I wrote about them here: http://www.righto.com/2016/05/inside-card-sorters-1920s-data.html http://www.righto.com/2016/05/inside-card-sorters-1920s-data...
  - WalterBright 9y ago
    > But if you punched a sequence number in these columns, a dropped deck could be easily sorted by a high-speed card sorter. I suppose heaven help you if you wanted to insert a statement between cards 37 and 38 :-)
    - 9y ago