Arduino Converts Serial To Parallel: The Paralleloslam

March 28, 2019 by Zoe Skyforest 34 Comments

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

January 26, 2019 by Jenny List 15 Comments

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.

Have Yourself A Recursive Little Christmas: Ornament That Prints Ornaments

December 24, 2018 by Dan Maloney 10 Comments

Sure there are the occasional functional Christmas tree ornaments; we had one that plugged into the lights and was supposed to sound like a bird gently trilling its song, but was in fact so eardrum-piercing that we were forbidden from using it. But in general, ornaments are just supposed to be for looks, right? Not so fast — this 3D-printed ornament has a 3D-printer inside that prints other ornaments. One day it might just be the must-have in functional Christmas decor.

Given that [Sean Hodgins] had only a few days to work on this tree-dwelling 3D-printer, the questionable print quality and tiny print volume can be overlooked. But the fact that he got this working at all is quite a feat. We were initially surprised that he chose to build a stereolithography (SLA) printer rather than the more common fused deposition modeling (FDM) printer, but it makes sense. SLA only requires movement in the Z-axis, provided in this case by the guts of an old DVD drive. The build platform moves in and out of a tiny resin tank, the base of which has a small LCD screen whose backlight has been replaced by a bunch of UV LEDs. A Feather M0 controls the build stage height and displays pre-sliced bitmaps on the LCD, curing the resin in the tank a slice at a time.

Results were mixed, with the tiny snowflake being the best of the bunch. For a rush job, though, and one that competed with collaborating on a package-theft deterring glitter-bomb, it’s pretty impressive. Here’s hoping that this turns into a full-sized SLA build like [Sean] promises.

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Vintage IBM 1403 Printer Problem Evades An Easy Fix

December 20, 2018 by Donald Papp 15 Comments

The Computer History Museum in Mountain View has two operational IBM 1401 mainframes, which use IBM 1403 high-speed printers. They aren’t some decades-old notion of “high speed” that barely looks sluggish today, either. These monsters slam out ten lines per second thanks to a rotating chain of type slugs and an array of electromagnetic hammers. Every 11.1 microseconds, a character in the chain would be lined up with a hammer, and if the control circuitry identified it as a character that needed to be printed, the hammer behind the paper would drive the paper into the print ribbon and the slug, putting an imprint of the character onto the paper. When one of these printers failed with a sync error, it kicked off some serious troubleshooting to diagnose the problem.

The IBM 1403’s type chain has a repeating set of characters that spins around at high speed. Unlike a typewriter or label maker, the hammers are not inside this unit. The hammers are on the outside, and work by pressing the paper onto the type slugs as the required characters line up.

Investigation of the problem ultimately led to an intermittent connection in a driver card due to a broken PCB trace, but by then some fuses had been blown as well. In the end the printer was brought back online, but possibly with a slightly damaged coil on one of the hammers.

[Ken]’s writeup on the repair process is highly detailed and walks through the kind of troubleshooting and repairs involved when solving problems with vintage electronics. Electrical fundamentals might be the same, but a deep understanding of not only the architecture but also the failure modes of vintage hardware is needed in order to troubleshoot effectively.

If IBM 1401 mainframes and fixing 1403 printers sounds familiar, it’s because a printer fix has been done before. That was due to a different problem, but still a challenging task to narrow down and fix.

Maze Generator Keeps Plotter (and Kids) Busy

December 15, 2018 by Tom Nardi 14 Comments

We can tell that [Jon Howell] is our kind of guy. After updating his vintage 1985 Hewlett-Packard plotter with WiFi and the ability to load SVG files, he obviously needed to find a bunch of stuff to run off with it. Gotta justify those hacks somehow. So he doubled down and decided support a hack with another hack by writing a maze generator to keep his plotter well fed. He was kind enough to unleash his creation on an unsuspecting Internet as an open source project, and now we all can benefit from a couple of reams worth of mazes.

The generator itself is written in Java, and should work on whatever operating system your box happens to be running thanks to the *nix and Windows wrapper scripts [Jon] provides. To create a basic maze, one simply needs to provide the script with the desired dimensions and the paper size. You can define the type of paper with either standard sizes (such as --paper a4) or in the case of a plotter with explicit dimensions (--paper 36x48in).

If you aren’t a big fan of right angles, there’s support for changing the internal geometry of the maze to use a hexagonal or triangle grid. You can even pass the program a black and white PNG “mask” which it will use as the boundaries for the maze itself, allowing for personalized puzzles of whatever shape catches your fancy. [Jon] even ran the Wrencher though his software, leading to the creation of a maze which we can neither confirm nor deny will be making an appearance on our Christmas cards this year.

Whether you need to prove to your significant other that the hours you spent fiddling with your plotter are well spent, or an easy way to entertain the junior humans in your life, you can thank [Jon] for your solution.

Weaponized Networked Printing Is Now A Thing

December 7, 2018 by Tom Nardi 37 Comments

It’s a fairly safe bet that a Venn diagram of Hackaday readers and those who closely follow the careers of YouTube megastars doesn’t have a whole lot of overlap, so you’re perhaps blissfully unaware of the man who calls himself [PewDiePie]. As such, you might not know that a battle between himself and another YouTube channel which uploads Bollywood music videos has reached such a fever pitch that his fans have resorted to guerrilla hacking to try to sway public opinion towards their side. It’s perhaps not the dystopian future we imagined, but it just might be the one we deserve.

To briefly summarize the situation, a hacker known only by the handle [TheHackerGiraffe] decided to help out Dear Leader by launching an automated attack against 50,000 Internet connected printers. When the hack was successful, the printer would spit out a page of digital propaganda, complete with fist ASCII art, that urged the recipient to go on YouTube and pledge their support for [PewDiePie]. There’s some debate about how many of the printers [TheHackerGiraffe] targeted actually delivered their payload, but judging by reactions throughout social media, it was enough to get the message out.

While the stunt itself may have come as a surprise, the methodology wasn’t. In fact, the only surprising element to the security researchers who’ve weighed in on the situation is that this hasn’t happened more often. It certainly isn’t the first time somebody’s done it, but the fact that this time its been connected to such a high profile Internet celebrity is putting more eyes on the problem then there have been in the past. Now that the proverbial cat is out of the bag, there are even websites springing up which claim to be purveyors of “Printer Advertising”. Odds are good this won’t be the last time somebody’s printer starts running off more than TPS reports.

We here at Hackaday don’t have much interest in the battle for YouTube supremacy. We’re just pulling for Dave Jones’s EEVBlog channel to join [AvE] in breaking a million subscribers. But we’re very interested in the technology which made this attack possible, how likely it is we’re going to see more people exploit it, and what are we supposed to do now that even our own printers can be turned against us?

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Maker Faire NY: Infinite Autonomous 3D Printing

September 27, 2018 by Brian Benchoff 7 Comments

Although it’s not an idea that has yet trickled down to $200 printers drop-shipped from China, one of the most innovative ideas in the 3D printing world in the last few years is putting plastic down on a conveyor belt. Yes, MakerBot was doing it back in 2010, but we’re not going to talk about that. Printing on a conveyor belt instead of a static bed allows you to easily print multiples of an object autonomously, without any human interaction. If you’re really clever, you could rotate the hot end 45° and build a piece of plastic that is infinitely long, like the printer [Bill Steele] built, the Blackbelt, or ‘the CAD files might exist somewhere’ Printrbot infinite build volume printer.

At this year’s World Maker Faire, we didn’t see an infinite printer, but we did catch a glimpse of an idea that could reliably take 3D printers into production. It’s a Multiprinter Autonomous 3D Printer, designed and built by [Thomas Vagnini].

The idea of using 3D printers for production and manufacturing is a well-studied problem. Lulzbot has a heated room filled with printers they use to manufacture all their machines. Prusa’s manufacturing facility is similarly well-equipped. However, both of these setups require helper monkeys to remove a part from the bed and set the machine up for the next print.

Instead of a strictly manual process, [Thomas]’ machine uses a sort of cartridge-based system for the printing bed. The glass beds are stored in a cassette, and for the first print, the printer pulls a bed onto the heated build plate through a system of conveyors. When the print is finished, the part and the bed ar fed into a rotating cassette, where it can be removed by a tech, prepped for the next print, and placed back in the ‘bed feeder’. It’s a system that brings the manual intervention cycle time of a 3D printer down to zero. If you’re producing hundreds of parts, this will drastically speed up manufacturing.

While it is a relatively niche idea, this is a very well-designed machine. It’s all laser cut, uses core-XY mechanics, and with the right amount of tuning, it does exactly what it says it will do. It’s not for everybody, but that’s sort of the point of manufacturing parts on a 3D printer.