Reviving A Casio Scientific Calculator, With A CNC Router

Before Wolfram Alpha, before the Internet, before even PCs, calculations more complex than what could be accomplished with a “four banger” required some kind of programmable calculator. There were many to choose from, if you had the means, and as time passed they became more and more sophisticated. Some even added offline storage so your painstakingly written and tediously entered programs didn’t evaporate when the calculator was turned off.

One such programmable calculator, a Casio PRO fx-1 with magnetic card storage, came across [amen]’s bench recently. Sadly, it didn’t come with any cards, so [amen] reverse engineered the card reader and brought the machine back to its 1970s glory. The oddball mag cards for it are no longer available, so [amen] had to make do with. He found some blank cards of approximately the right size for cheap, but somehow had to replicate the band of vertical stripes adjacent to the magnetic strip on the card. Reasoning that they provide an optical synchronization signal, he decided to use a CNC router to cut a series of fine-pitched slots in the plastic card. It took a little effort to get working, including tapping the optical sensor and reading the signal on an oscilloscope, but as the video below shows, the hacked cards work fine with the vintage calculator.

Kudos to [amen] for reviving this retro-cool calculator. Now that it’s back in action, it might be fun to visualize domains on the magnetic strip. A flatbed scanner can be used for that job.

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The Jookbox Is A Post-Modern Jukebox

The family of [Chris Patty] decided that their holiday gifts would have to be handmade. So, he decided to make something new for his father: a jukebox with a twist. Instead of a touchscreen or web interface, his jukebox uses swipe cards. To play a track, you find the card for the song you want to hear, swipe it, and the jukebox plays the requested track. The whole thing is built into a wooden box that hides its digital nature, which is built using a Raspberry Pi and a credit card stripe reader.

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Card Reader Lockout Keeps Unauthorized Tool Users At Bay

It’s a problem common to every hackerspace, university machine shop, or even the home shops of parents with serious control issues: how do you make sure that only trained personnel are running the machines? There are all kinds of ways to tackle the problem, but why not throw a little tech at it with something like this magnetic card-reader machine lockout?

[OnyxEpoch] does not reveal which of the above categories he falls into, if any, but we’ll go out on a limb and guess that it’s a hackerspace because it would work really well in such an environment. Built into a sturdy steel enclosure, the guts are pretty simple — an Arduino Uno with shields for USB, an SD card, and a data logger, along with an LCD display and various buttons and switches. The heart of the thing is a USB magnetic card reader, mounted to the front of the enclosure.

To unlock the machine, a user swipes his or her card, and if an administrator has previously added them to the list, a relay powers the tool up. There’s a key switch for local override, of course, and an administrative mode for programming at the point of use. Tool use is logged by date, time, and user, which should make it easy to identify mess-makers and other scofflaws.

We find it impressively complete, but imagine having a session timeout in the middle of a machine operation would be annoying at the least, and potentially dangerous at worst. Maybe the solution is a very visible alert as the timeout approaches — a cherry top would do the trick!

There’s more reading if you’re one seeking good ideas for hackerspace. We’ve covered the basics of hackerspace safety before, as well as insurance for hackerspaces.

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Just Swipe Your Card And Enter The Pin… What Could Go Wrong?

We do hope this project makes you shiver.

“Financial risks” is an audiovisual installation that reacts when you swipe your credit card and prints an odd looking receipt if you type in your pin-code. Even though the website contains few technical details (read none) about the build, we chose to feature the project as we find his intent interesting:

‘Financial Risks’ installation is a project designed to present an ironical viewpoint on encoded wallets, as a data input interface invites to overcome fear of impossibility to control spread of confidential information for the sake of curiosity of interaction with an object of art.

The piece consists of 6 bank card readers, a hardware system of sound and video synthesis, a keyboard for pin code entering, a 2-channel sound system and a cash register printer configured to print images. Up to 6 cards simultaneously may be used for playing.

We do hope that nothing is stored in the platform’s memory… but is the installation monitored?

Quick And Dirty Magnetic Card Reader

card

[nevdull] found himself in possession of a magnetic card reader. What else was he to do but show us all how to read from it using an AVR? He goes through the basics of how the card reader works, as well as how to detect the different card states such as entering, reading, leaving. There is source code to download to try for yourself, but unless you have the same reader, you’ll have to do some modifications. While this doesn’t get you all the way to reading the complete content off of the card, its a great start. Maybe you guys can help him finish up the last bits.

Magnetic Stripe Card Spoofer

After building a USB magnetic stripe reader, [David Cranor] has found a way to fool a magnetic stripe reader using a hand-wound electromagnet and an iPod. The data on a card is read and stored on a computer, then encoded as a WAV file using a C++ program. The iPod plays the WAV file with the data through a single-stage opamp amplifier connected to the headphone jack. The amplifier is used to drive the electromagnet. Video embedded after the jump.

By no means is this a new idea. There have been a lot of mangetic stripe projects and software. This project in particular references the 1992 Phrack article “A Day in the Life of a Flux reversal” by [Count Zero].

Don’t get your hopes up just yet on strolling through high security installations using this little device. It can only replay the data from a card that has been recorded. If you don’t have a known working card, it won’t get you very far.

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Pin Terminal Tetris


I’ve never trusted putting my PIN number at a store, and now I’m glad I don’t. In an effort to prove just how hackable those handy input terminals are, [saar drimmer] and [steven murdoch] replaced the guts of a pin terminal with… tetris. Hmm, now I need a gameboy tetris fix Thanks [terti]

A word of warning, the embedded video made Mozilla nutty on my usually rock solid machine.