cassette

49 Articles

Fisher Price Bluetooth Speaker Hack

August 7, 2015 by 14 Comments

A good hacker hates to throw away electronics. We think [Matt Gruskin] must be a good hacker because where a regular guy would see a junky old 1980’s vintage Fisher Price cassette player, [Matt] saw a retro stylish Bluetooth speaker. His hack took equal parts of electronics and mechanics. It even required some custom 3D printing.

You might think converting a piece of old tech to Bluetooth would be a major technical challenge, but thanks to the availability of highly integrated modules, the electronics worked out to be fairly straightforward. [Matt] selected an off the shelf Bluetooth module and another ready-to-go audio amplifier board. He built a custom board to convert the stereo output to mono and hold the rotary encoder he used for the volume control. An Arduino (what else?) reads the encoder and also provides 3.3V to some of the other electronics.

The really interesting part of the hack is the mechanics. [Matt] managed to modify the existing mechanical buttons to drive the electronics using wire and hot glue. He also added a hidden power switch that doesn’t change the device’s vintage look. Speaking of mechanics, there’s also a custom 3D printed PCB holder allowing for the new board to fit in the original holder. This allows [Matt] to keep the volume control in its original location

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Microcassette Recorders Become A Tape Delay

June 17, 2015 by 25 Comments

Long before audio engineers had fancy digital delays, or even crappy analog delays, there were tape delays. Running a tape around in a loop with a record and play head is the basis of the Echoplex and Space Echo, and both of these machines are incredible pieces of engineering.

Microcassette recorders are not, in general, incredible pieces of engineering. They do, however, have a strip of magnetic tape, a record head, and a play head. Put two of them together, and you can build your own tape delay.

The basic principle of a tape delay is simple enough – just run a loop of tape round in a circle, through a record and playback head, record some audio, and send the output to an amplifier. In practice, it’s not that simple. [dogenigt] had to manufacture his own tape loop from microcassettes, a process that took far too long and was far too finicky.

For a control circuit, [dogenigt] is using four audio pots and one linear pot for speed control. The audio pots are responsible for input gain, feedback, the amplitude of the clean signal, and the output of the signal after it’s been run through the delay.

Apart from being one of those builds that’s very dependent on the mechanical skill of the builder, it’s a pretty simple delay unit, with all the electronics already designed for a stripboard layout. You can hear an example of what it sounds like below.

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Bringing A Century Stereo Into The 21st Century

June 9, 2015 by 14 Comments

Way back in the previous century, people used to use magnetized strips of tape to play music. It might be hard to believe in today’s digital world, but these “cassette” tapes were once all the rage. [Steve] aka [pinter75] recently found a Bang & Olufsen stereo with this exact type of antequated audio playback device, and decided to upgrade it with something a little more modern.

Once the unit arrived from eBay and got an electronic tune-up, [pinter75] grabbed a Galaxy S3 out of his parts drawer and got to work installing it in the old cassette deck location. He used a laser cutter to make a faceplate for the phone so it could be easily installed (and removed if he decides to put the tape deck back in the future).

The next step was wiring up power and soldering the audio output directly to the AUX pins on the stereo. Once everything was buttoned up [pinter75] found that everything worked perfectly, and mounted the stereo prominently on his wall. It’s always great when equipment like this is upgraded and repaired rather than thrown out.

Peripherals Behind The Iron Curtain

April 13, 2015 by 39 Comments

The article Home Computers Behind the Iron Curtain sparked a lot of interest, which made me very happy. Therefore, I decided to introduce more computer curiosities from the Iron Curtain period, especially from the former Czechoslovakia (CSSR).

As I mentioned in the previous article, the lack of spare parts, literature and technology in Czechoslovakia forced geeks to solve it themselves: by improvisation and what we would today call “hacking.”  Hobbyist projects of one person or a small party was eventually taken over by a state-owned enterprise, which then began to manufacture and deliver to stores with some minor modifications. These projects most often involved a variety of peripherals that could only be found in the Czechoslovakia with great difficulty.

Much like the production of components, the production of peripherals was also distributed throughout the eastern block so that each country was specializing in certain types of peripherals. For example, East Germany produced matrix printers, and Bulgaria made floppy disks drives. This meant industrial enterprises had to wait for vital computer parts, because the production in another country was not sufficient to cover even the local requirements, let alone the home user.

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Transferring Audio To An AVR At 12kbps

November 30, 2014 by 20 Comments

Back in the bad ‘ol days of computing, hard drives cost as much as a car, and floppy drives were incredibly expensive. The solution to this data storage problem offered by all the manufacturers was simple – an audio cassette. It’s an elegant solution to a storage problem, and something that has applications today.

[Jari] was working on a wearable message badge with an 8-pin ATTiny. To get data onto this device, he looked at his options and couldn’t find anything good; USB needs two pins and the firmware takes up 1/4 of the Flash, UART isn’t available on every computer, and Bluetooth and WiFi are expensive and complicated. This left using audio to send digital data as the simplest solution.

[Jari] went through a ton of Wikipedia articles to figure out the best modulation scheme for transferring data with audio. What he came up with is very simple: just a square wave that’s changed by turning a pin off and on. When the audio is three samples long without crossing zero, the data is 0. When it’s five samples long without crossing zero, the data is 1. There’s a 17-sample long sync pulse, and with a small circuit that acts as a zero crossing detector, [Jari] had a simple circuit that would transfer data easily and cheaply.

All the code for this extremely cheap modem is available on GitHub.

The Cassette MP3 Player

October 9, 2014 by 34 Comments

1994 was twenty years ago. There are people eligible to vote who vaguely remember only one Bush presidency. You can have a conversation with someone born after the millennium, and they think a 3.5 inch disk is called a save icon. Starting to feel old? Don’t worry, all the trinkets of your youth have now become shells for MP3 players, the cassette tape included.

[Britt] is aware you can pick up one of these cassette tape MP3 players through the usual channels, but she wanted her build to be a little different. She’s using ar real, vintage cassette tape for starters, and from the outside, looks pretty much like any other cassette tape: there’s a thin strip of tape at the bottom, and the clear plastic window shows the tape is at the beginning of side A.

Outside appearances are just that; inside, there is a small, repurposed MP3 player, with tact switches wired up to the old buttons, actuated by moving the spools back and forth. Yes, you actually play, pause, rewind and fast forward by sticking a pencil in the spool and moving it back and forth. Amazing.

It’s a great build, and considering both cassette tapes and cheap MP3 players can be found in the trash these days, it’s something that should be hard to replicate.

The Entire Commodore 64 Library In Your Pocket

July 25, 2014 by 15 Comments

[sweetlilmre] is just beginning his adventures in retrocomputing, and after realizing there were places besides eBay to buy old computers, quickly snagged a few of the Amigas he lusted after in his youth. One of the machines that didn’t make it into his collection until recently was a Commodore 64 with Datasette and 1541 drive. With no tapes and a 1541 disk drive that required significant restoration, he looked at other devices to load programs onto his C64.

These devices, clever cartridge implementations of SD cards and Flash memory, cost more than anyone should spend on a C64. Realizing there’s still a cassette port on the C64, [sweetlilmre] created Tapuino, the $20 Commodore tape emulator

The hardware used to load games through the Datasette connector included an Arduino Nano, a microSD breakout board, a 16×2 LCD, some resistors, buttons, and a little bit of wire. The firmware part of the build – available here on the Git – reads the .TAP files off the SD card and loads them into the C64.

[sweetlilmre] posted a very complete build post of the entire device constructed on a piece of protoboard, Pop that thing in a 3D printed case, and he can have the entire C64 library in his pocket.