Reinking Dot Matrix Printer Ribbons Because It’s Fun, Okay

Ink! No matter the printer you’ve got, whether it be inkjet, laser or otherwise, it’s the consumables that will send you broke. At times, the cost of Hewlett-Packard black ink has exceeded the price per volume of human blood, and shareholders around the world have rejoiced.

As a retrocomputing reprobate, I have a personal dilection for printers of the vintage persuasion. My previous dalliances have involved fully fledged office copiers, but lately I’ve found myself tinkering with dot matrixes of a 1980s vintage. These workhorses are now reaching middle age, and as you’d expect, their ribbons are a little worse for wear after all this time.

Replacements are cheap enough for the most common printers, but shipping takes weeks and hackers are an impatient bunch. Plus, if you’ve got one of the more obscure models, it’s unlikely you’ll find a fresh cart just sitting on the shelf. It was these factors that spurred my good friend [Cosmos2000] and I into action.

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Arduino Converts Serial To Parallel: The Paralleloslam

After a youth spent playing with Amigas and getting into all sorts of trouble on the school computer network, I’ve always had a soft spot in my heart for hardware from the 80s and 90s. This extends beyond computers themselves, and goes so far as to include modems, photocopiers, and even the much-maligned dot matrix printer.

My partner in hacking [Cosmos2000] recently found himself with a wonderful Commodore MPS 1230 printer. Its parallel interface was very appropriate in its day, however parallel ports are as scarce as SID chips. Thankfully, these two interfaces are easy to work with and simple in function. Work on a device to marry these two disparate worlds began.

Enter: The Paralleloslam

While I was gallivanting around the Eastern coast of Australia, [Cosmos2000] was hard at work. After some research, it was determined that it would be relatively simple to have an Arduino convert incoming serial data into a parallel output to the printer. After some testing was performed on an Arduino Uno, a bespoke device was built – in a gloriously plastic project box, no less.

An ATMEGA328 acts as the brains of the operation, with a MAX232 attached for level conversion from TTL to RS232 voltage levels. Serial data are received on the hardware TX/RX lines. Eight digital outputs act as the parallel interface. When a byte is received over serial, the individual bits are set on the individual digital lines connected to the printer’s parallel port. At this point, the strobe line is pulled low, indicating to the attached device that it may read the port. After two microseconds, it returns high, ready for the next byte to be set on the output lines. This is how parallel interfaces operate without a clock signal, using the strobe to indicate when data may be read.

At this point, [Cosmos2000] reached out – asking if I had a name for the new build.

“Hm. Paralleloslam?”

“Done. Cheers!”

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Restoring A Forgotten Dot-Matrix Printer

Dot matrix printers are the dinosaurs that won’t go extinct. They are not unlike a typewriter with the type bars behind the ink ribbon replaced by a row of metal pins controlled by solenoids, each pin being capable of printing a single pixel. At their best they could deliver a surprising level of quality, but their sound once heard is not forgotten, because it was extremely LOUD.

[Wpqrek] bought an old dot-matrix printer, a Commodore MPS 803. Sadly it didn’t live up to the dot-matrix reputation for reliability in that it didn’t work, some of its pins weren’t moving, so he set to on its repair. Behind each of those pins was a solenoid, and after finding a crack in the flexible ribbon to the head he discovered that some of the solenoids were open-circuit. On dismantling the head it became apparent that the wires had detached themselves from the solenoids, so he very carefully reattached new wires and reassembled the unit. Of course, he had no replacement for the flexible ribbon, so he made a replacement with a bundle of long lengths of flexible hook-up wire. This hangs out of the top of the printer as it follows the carriage, but for now it keeps the device working.

Dot-matrix printers are a favourite for our readership. Among others, we’ve seen another Commodore get the Python treatment, as well as an Apple capable of printing in full colour.

Hackaday Podcast Ep3 – Igloos, Lidar, And The Blinking LED Of RF Hacking

It’s cold outside! So grab a copy of the Hackaday Podcast, and catch up on what you missed this week.

Highlights include a dip into audio processing with sox and FFMPEG, scripting for Gmail, weaving your own carbon fiber tubes, staring into the sharpest color CRT ever, and unlocking the secrets of cheap 433 MHz devices. Plus Elliot talks about his follies in building an igloo while Mike marvels at what’s coming out of passive RFID sensor research.

And what’s that strange noise at the end of the podcast?

Direct Download (59.2 MB MP3)

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Python Resurrects Dot Matrix Printing

These days a printer — especially one at home — is likely to spray ink out of nozzles. It is getting harder to find home laser printers, and earlier printer technologies such as dot matrix are almost gone from people’s homes even if you’ll still see a few printing multipart forms in some offices.

[Thomas Winningham] bought an old Commodore dot matrix printer in a fast food parking lot for $20. How hard could it be to get it working? How hard, indeed. Check out the video below to see the whole adventure. The principle behind the printer is simple enough. The head has one or two rows of pins each controlled by a solenoid. The head moves across the paper and your job — should you decide to accept it — is to make the pins push out at the right spot. An ink ribbon like a typewriter uses — oh yeah, more vanishing tech — leaves ink on the paper where it gets punched by the pin.

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Mini-Banners For Small Occasions

Do you often find yourself needing to make small signs? Perhaps you’re trying to put a notice on the office fridge, but you’re just not in the mood for the usual Comic Sans-on-A4 staple today. A banner of some sort would do the trick, but… a small one, right? [Mike Ingle] has the answer – making mini-banners on old receipt printers.

[Mike] was a fan of Paint Shop in the 1980s, which among other things, enabled the printing of long banners on the popular dot matrix printers of the era. Realising that receipt printers have a similar ability to print on a long continuous strip of paper, he decided to see if it was possible to create small banners using the hardware.

The hack is simple – ImageMagick is used to generate a one-bit black & white bitmap that is then processed with some custom C code to generate something the printer can understand. It’s then a simple matter of hacking up the original RS-232 cable to fit a DB-9 (aka DE-9) connector, and spitting out the instructions over serial.

The mini-banners are cool, and we could imagine having some fun with such a project, using it to print out tweets or putting it into service as a stock ticker. It’s a great example of cleanly interfacing with existing hardware to create something outside of the original design intentions. Such printers are fertile ground for hacks – like this printer that can spit out the US Constitution in 6 seconds flat.