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Web camera as a paper tape reader?

Here's a paper tape punch on ebay (pretty imposing looking gadget):

Paper tape punch

I've got a few punches (perforators actually) as well, but nothing quite as fast as that one; looks like it might be a bit of a challenge to interface though.

Unlike the readers, perfs are obviously much more complex mechanically and thus also usually much heavier; can't really pull the tape through by hand very well although I do seem to recall seeing a manual punch a looong time ago (I do have a manual 80-column card punch though, and it even prints on the card!)

I've scrapped a few in my time and have some parts like punch blocks, feed wheels etc., but I can't really imagine building one from scratch even with the crucial parts...
 
Actually, the basic circuitry is a lot simpler than that; the critical part of course is the 9-position photo sensor; run that into a transistor array or a couple of Schmitt trigger driver ICs using the feed hole for a clock and that's usually all you need.

Is a schmitt trigger enough to de-glitch the photo sensors? I would also add a de-bounce latch circuit on at least the sensor on the sprocket hole (clock). Now let's figure out how to add a stepper motor so we won't wear ourselves out pulling the tape across the sensors. :)
 
Is a schmitt trigger enough to de-glitch the photo sensors? I would also add a de-bounce latch circuit on at least the sensor on the sprocket hole (clock). Now let's figure out how to add a stepper motor so we won't wear ourselves out pulling the tape across the sensors. :)
Can't hurt to condition the signals but you could also do a pretty good job in the reading software; mind you, if you did add a UART to turn it into a serial device then you probably would have trouble with the odd fuzzy hole or dust.

Don't even need the complication of a stepper. Most of mine just use an ordinary AC motor like an old turntable or fan motor; matter of fact, the SCM units do have a cooling fan blade on the end of the drive motor (geared down a bit for the drive sprocket of course).
 
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Well, when someone asks what you want to read with your paper tape reader, answering "paper tape" does sound a little, umm, smart-assish...
Maybe it' is because english isn't my native language, but I didn't read that in your question at all. The discussion had strayed a bit, and you did ask "what you're planning to read with this gizmo?" instead of "paper tape reader".

Sorry if you confused me so I confused you.
 
Someone is selling a new reader on ebay for quite a bit of money. But it will give you an idea of the simple circuitry.
I can't help thinking that he would sell a lot more of them if the price was 25 bucks instead.....
 
Maybe it' is because english isn't my native language, but I didn't read that in your question at all. The discussion had strayed a bit, and you did ask "what you're planning to read with this gizmo?" instead of "paper tape reader".

Sorry if you confused me so I confused you.
Yeah, the way these things drift off-topic I can understand that and maybe shouldn't have assumed that the "web camera as a paper tape reader" header would make it obvious what I meant by "gizmo."

But I was just teasing you with my "smart ass" comment and hope you didn't take it seriously (or, if you did, that you don't now); I have heard that due to the cold climate Norwegians have even less of a sense of humour than Canadians, but that's not true is it?

The reason I asked was in case you were primarily concerned with reading the tapes (instead of building a camera-based reader) then there are folks around who could do that for you, especially if they were of general interest (outside of Norway that is ;-) )
 
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How I miss Byte Magazine! Did you know that you can till read monthly articles about Jerry Pournelle's trial and tribulations with getting things to work on his PC? The guy is a good writer but has never learned how a computer works.

Jerry Pournelle
Cool! I didn't know that Chaos Manor was still around; it usually provided a (probably unintentional) chuckle in every issue and "Real Soon Now" long ago became an oft-used-since part of my vocabulary.
 
I can't help thinking that he would sell a lot more of them if the price was 25 bucks instead.....

Yes, I agree. But there can not be a very big market for tape readers. However, if I had an old computer with a big pile of tapes, I might want one of those but at that price I would build a "kludge" (a quick & ugly home made version). Mike and I can help you get one to work.
-Dave
 
Yes, I agree. But there can not be a very big market for tape readers. However, if I had an old computer with a big pile of tapes, I might want one of those but at that price I would build a "kludge" (a quick & ugly home made version). Mike and I can help you get one to work.
-Dave
Hmm, this discussion is starting to motivate me to whip up an interface for one of the perforators so I can actually punch some tapes; I threw out boxes of tapes back when old computers were just junk and now there are only two or three that missed the purge left to play with.

We used to also "print" banners of text along the tape using the holes like a dot matrix printer; great for birthday and anniversary parties, especially with coloured tape (and the chad was for weddings of course). Many of the old system tapes did that as well to label the tapes instead of just writing or sticking labels on them.
 
Can't hurt to condition the signals but you could also do a pretty good job in the reading software; mind you, if you did add a UART to turn it into a serial device then you probably would have trouble with the odd fuzzy hole or dust.

I don't remember too much about paper tape data formats. Was there a parity bit on each row of data or were there sumcheck words at the end? I hope you did not have to verify the data by running the tape through a second time?
 
Most computer-oriented paper tapes of the 60's and later were 8 channel. The 8th channel was normally used for parity, unless binary was being punched.

However, paper tape was used on a lot of gear, from early CNC to telegrams. Tape using 5 level Baudot encoding was used for a very long time. There are also 6 and 7 level paper tapes.

Punched cards were a great improvement over tape, although the chad wasn't nearly as much fun with which to play pranks...
 
Most computer-oriented paper tapes of the 60's and later were 8 channel. The 8th channel was normally used for parity, unless binary was being punched.

However, paper tape was used on a lot of gear, from early CNC to telegrams. Tape using 5 level Baudot encoding was used for a very long time. There are also 6 and 7 level paper tapes.

Punched cards were a great improvement over tape, although the chad wasn't nearly as much fun with which to play pranks...
...And then there were edge punched cards, which were more or less the size of 80 column cards but with holes like paper tape along one edge (punched and read the same way as paper tape); unlike normal punched cards they had lots of room for printed text for human eyes, and also corresponding (or different) machine-readable data along the edge.

I'll try to find some of this stuff and post some pictures.
 
While you're at it, post some photos of some aperture cards.

Ya got me with that one, Chuck; never heard of 'em till now. Neat idea though; are they still used today?

Here's a pic, shamelessly stolen from the wiki:

attachment.php
 
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I have no doubt that there are still many drawers full of them out there. Since most of these things are part of archive collections and have a very long life, there's no particular rush (or probably funding) in getting them all converted to more modern (and perhaps less permanent) media.
 
I have no doubt that there are still many drawers full of them out there. Since most of these things are part of archive collections and have a very long life, there's no particular rush (or probably funding) in getting them all converted to more modern (and perhaps less permanent) media.
That's what I was thinking; as long as there's still equipment around to read 'em, they look a lot more permanent than most modern alternatives (well, of course there's microfiche but I assume the advantage of these was that the index info was machine-readable).

I'm always impressed by the number of different and often ingenious ideas that have come and gone in the last 50 years or so...
 
But I was just teasing you with my "smart ass" comment and hope you didn't take it seriously (or, if you did, that you don't now);
No, I didn't take it seriously, but the oppurtunity was to good to let go of the chance to tease back. ;^)
I have heard that due to the cold climate Norwegians have even less of a sense of humour than Canadians, but that's not true is it?
I haven't met many Canadians, but I shouldn't think it is true. Most Norwegians have a great sense of humour, but we are a bit reserved, and it can take a while before we "warm up" to new people.

The reason I asked was in case you were primarily concerned with reading the tapes (instead of building a camera-based reader) then there are folks around who could do that for you, especially if they were of general interest (outside of Norway that is ;-) )
I have only three tapes; and they contains some of my old school projects and such, so I hardly think that others have an interest.

I tried to find a paper tape reader at a reasonable price, or one that I could build with components that are available at a reasonable price. When that failed, it sparked an interest in finding a general way to read paper tapes today.
 
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