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Web camera as a paper tape reader?

Chuck(G) said:
You realize, of course, if you wanted to keep this thing completely vintage, you wouldn't wimp out with any of that solid-state stuff--you'd use an array of vacuum phototubes (still made by Hamamatsu):

8F15AD49A16847E0878789C4CF2FFE70.jpg
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And how do you suggest to mount those phototubes so that eight (nine actually, with the sprocket) will fit the width of a paper tape?
:)
 
Chuck(G) said:
Another possibility might be the sensor from a flatbed scanner, particularly one that can also scan 35 mm slides or negatives.
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Aren't flatbed scanner using ccd's just like digital cameras?
What would make a scanner better suited?
 
Chuck,
I knew you had an answer to that question, but mixing vacuum phototubes and fiber optics! Now that's either genius 'out of the box' thinking or maybe we should call the guys in the white outfits from the funny farm to come pick you up. :)
-Dave
 
dave_m said:
Chuck,
I knew you had an answer to that question, but mixing vacuum phototubes and fiber optics! Now that's either genius 'out of the box' thinking or maybe we should call the guys in the white outfits from the funny farm to come pick you up. :)
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It wouldn't need to be fiber necessarily. you could use glass rods or mirrors.

How about this? A spinning mirror and a single photocell that scans the width of the tape? Come to think of it, why couldn't you modify a supermarket barcode scanner?

You could also do the job with vacuum switches that are activated as the tape is passed over a perforated plate, player-piano style.
 
Chuck(G) said:
It wouldn't need to be fiber necessarily. you could use glass rods or mirrors.

How about this? A spinning mirror and a single photocell that scans the width of the tape? Come to think of it, why couldn't you modify a supermarket barcode scanner?

You could also do the job with vacuum switches that are activated as the tape is passed over a perforated plate, player-piano style.
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... or little wire brushes like the unit record punched card readers...

I used to have one that pushed little pins up through the tape; the pins were linked to interposer bails on a mechanical keyboard and effectively "pressed" the corresponding keys.

But I prefer the simplicity of my various optical readers; a light bulb on top, a 9-element photo sensor and a driver IC/transistor array. And a motor to move the tape of course.
 
MikeS said:
But I prefer the simplicity of my various optical readers; a light bulb on top, a 9-element photo sensor and a driver IC/transistor array. And a motor to move the tape of course.
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A bit of trivia. I once attended a Data General NOVA minicomputer training class for new users and the instructor mentioned that the light source on their paper tape reader was a VW brake light bulb. He said they tested it and found it produced a very consistent light output.
 
MikeS said:
Smart ass!

What's *ON* those paper tapes?

Sheesh...
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Smart ass yourself.
Computer programs (and source code), in this case from an old 16-bit computer from an old Norwegian company. Thiunk before Norsk Data.

Sheesh ... some people doesn't even know how to ask questions properly,

:)
 
tingo said:
Smart ass yourself.
Computer programs (and source code), in this case from an old 16-bit computer from an old Norwegian company. Thiunk before Norsk Data.

Sheesh ... some people doesn't even know how to ask questions properly,

:)
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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...

And I had even sort of assumed that the tapes contained computer programs or data of some kind...
 
dave_m said:
A bit of trivia. I once attended a Data General NOVA minicomputer training class for new users and the instructor mentioned that the light source on their paper tape reader was a VW brake light bulb. He said they tested it and found it produced a very consistent light output.
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Not unusual; several of my PPT readers use a standard 12V single-filament automotive bulb and it doesn't seem to be very critical at all.
 
anyone got any schematics for making your own papertape reader? or is this a very complicated project and schematics don't exist for it?
 
little update about tubes: I don't have any of those in the boxes and they're running about $30 each nowadays. I was shocked on both counts.

I'd also like to learn about making a paper tape reader or maybe a writer (hole puncher, I know). Now that I'm thinking about it (might be the fever talking) that would make an excellent encryption method; if everything is on physical media like paper tapes it would be time consuming and very impractical to try to steal.
 
OT:
NathanAllan said:
little update about tubes: I don't have any of those in the boxes and they're running about $30 each nowadays. I was shocked on both counts.
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I had a similar shock about 30 years ago. I had bought an amp which didn't have the tubes and they wanted about 50 bucks for a used set. These were common and previously cheap tubes and in a store that wasn't gouging.

I'd also like to learn about making a paper tape reader or maybe a writer (hole puncher, I know). Now that I'm thinking about it (might be the fever talking) that would make an excellent encryption method; if everything is on physical media like paper tapes it would be time consuming and very impractical to try to steal.
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Don't fool yourself on the encryption. My second wife had trained as a teletype operator and she could read the tape visually. That was in Japan and apparently all operators were taught that skill. I assume it was the same here. You can't win! Probably the best way to hide stuff is to write it with vinegar on a hard boiled egg. lol
 
General Dynamics, nice. I meant encryption past the codes themselves, not paper tape as an encryption method. I think that was the fever kicking when I said that.
 
dave_m said:
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.

tape reader on ebay
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Whooeee... I remember those being a lot cheaper...

I've got a few PPT readers (motor driven at that), and the price just went up substantially ;-)

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.
 
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