Planet Arduino

Input devices consisting of optical readers for punched paper tape have been around since the earliest days of computing, so why stop now? [Jürgen]’s Paper Tape Reader project connects to any modern computer over USB, acting like a serial communications device. Thanks to the device’s automatic calibration, it works with a variety of paper materials. As for reading speed, it’s pretty much only limited to how fast one can pull tape through without damaging it.

While [Jürgen]’s device uses LEDs and phototransistors to detect the presence or absence of punched holes, it doesn’t rely on hardware calibration. Instead, the device takes analog readings of each phototransistor, and uses software-adjusted thresholds to differentiate ones from zeros. This allows it to easily deal with a wide variety of tape types and colors, even working with translucent materials. Reading 500 characters per second isn’t a problem if the device has had a chance to calibrate.

Interested in making your own? The build section of the project has all the design files; it uses only through-hole components, and since the device is constructed from a stack of 1.6 mm thick PCBs, there’s no separate enclosure needed.

Paper tape and readers have a certain charm to them. Cyphercon 4.0 badges featured tape readers, and we’ve even seen the unusual approach of encoding an I²C byte stream directly onto tape.

Feeling a little nostalgic? Dying to read some paper ticker tapes? You can do it manually, but that’d take forever! [NeXT] decided to make a little PCB to help him out.

Having searched for paper tape readers for years, and even getting halfway through building the mechanical portion of it in his high-school tech class, [NeXT] decided to take a serious stab at it — and by golly, it works!

The reason he finally decided to go down this route is because you just can’t buy them (well, for cheap), and even the DIY or hobby ones out there are notoriously slow — what better reason to design it from scratch?

What we love about this hack is its clever reuse of perfboard — it just so happens that the spacing of his paper tape holes line up perfectly with the holes in the perfboard! Don’t you love it when engineers work together with nice, even, standard units? After discovering this it was just a matter of adding some photo-transistors on one side of the perfboard sandwich, and LEDs on the other side.  A bit of soldering, some Schmitt triggers, and an Arduino Pro Mini later… and bam you have a serial output of data!

The funny thing is — he does actually have a working ASR33 Teletype reader — but it’s too slow. Maybe we should mail him the secret message Hack42 gave us on paper tape when we visited them in the Netherlands!

[Thanks John!]

Back before the days of 8 inch floppy disks, storing computer programs was much more primitive than even a stack of punch cards. The earliest general purpose computers used paper tape, a strip of paper with punched holes designating a 0 or a 1. Thankfully for the computer scientists of the day, these paper tapes weren’t created by hand. No, the Friden SP-2 tape punch took care of the duties of punching holes in these tapes. When [Max] rescued one of these tape punch machines from a trash bin, he knew what he needed to do: connect it to an Arduino so he could create his own paper tapes.

[Max] found a veroboard with a bunch of transistors inside the machine that was added by a previous owner. After finding the manual for the machine he connected it to an Arduino, holding each of the eight control pins high to punch the tape, and then holding another pin high to advance the tape. With this, he was able to punch letters instead of binary code into his paper tape.

[Max] also added an Ethernet shield to his Arduino that checks his email. If an email shows up in a special folder, it outputs the subject line to the tape punch machine, giving him an entirely retro ticker tape machine, built with vintage 60s hardware.

There are a pair of videos of [Max]‘s tape punch machine in action below, along with a gallery of the glamorous gut shots of this incredible machine.