Annotate PDFs On Linux With PDFrankenstein

May 28, 2022 by Donald Papp 20 Comments

On Windows and Mac machines, it’s not too troublesome to add text or drawings (such as signatures) to PDF files, but [Mansour Behabadi] found that on Linux machines, there didn’t seem to be a satisfying way or a simple tool. Being an enterprising hacker, [Mansour] set out to fill that gap, and the way it works under the hood is delightfully hacky, indeed.

The main thing standing in the way of creating such a tool is that the PDF format is a complex and twisty thing. Making a general-purpose PDF editing tool capable of inserting hyperlinks, notes, images, or drawings isn’t exactly a weekend project. But [Mansour] didn’t let that stop him; he leveraged the fact that tools already exist on Linux that can read and create PDF files, and tied them all together into what was at one point “a horrific patchwork of tools” which inspired the name pdfrankenstein.

The tool is a GUI that uses Inkscape and qpdf to convert a PDF page to an SVG file, set it as a locked background, then let the user add any annotations they desire, using Inkscape as the editor. After changes are made, the program removes the background, overlays the annotations back onto the originals, and exports a final file. Annotations can therefore be anything that can be done in Inkscape.

Curious about these and other tools for handling PDFs? We’ve shared some programs and tricks when we previously covered dealing with the PDF format in Linux.

AI Attempts Converting Python Code To C++

May 28, 2022 by Donald Papp 31 Comments

[Alexander] created codex_py2cpp as a way of experimenting with Codex, an AI intended to translate natural language into code. [Alexander] had slightly different ideas, however, and created codex_py2cpp as a way to play with the idea of automagically converting Python into C++. It’s not really intended to create robust code conversions, but as far as experiments go, it’s pretty neat.

The program works by reading a Python script as an input file, setting up a few parameters, then making a request to OpenAI’s Codex API for the conversion. It then attempts to compile the result. If compilation is successful, then hopefully the resulting executable actually works the same way the input file did. If not? Well, learning is fun, too. If you give it a shot, maybe start simple and don’t throw it too many curveballs.

Codex is an interesting idea, and this isn’t the first experiment we’ve seen that plays with the concept of using machine learning in this way. We’ve seen a project that generates Linux commands based on a verbal description, and our own [Maya Posch] took a close look at GitHub Copilot, a project high on promise and concept, but — at least at the time — considerably less so when it came to actual practicality or usefulness.

Bi-Color Filament Kicks 3D Printed Optical Illusions Up A Notch

May 22, 2022 by Donald Papp 2 Comments

A new video from [Make Anything] shows off a nice combo that has a real visual impact: ambiguous shapes that look different depending on what angle they are viewed at, combined with an unusual filament that enhances the effect greatly. As you can see in the image above that shows off just such an object in front of a mirror, the results are pretty striking.

Japanese mathematician and artist [Kokichi Sugihara] figured out the math behind such objects, of which his ambiguous cylinder illusion is probably the most well-known. That inspired [Make Anything] to create his own strange objects, which he showcases happily. He adds one more twist, however.

This filament is split right down the middle in two colors.

What is a natural complement to an object that looks different based on the direction from which it is viewed? A filament whose color depends on what direction it is viewed, of course! The filament in question is MatterHackers Quantum dual-color PLA, and this unusual filament is split right down the middle in two different colors, resulting in a printed object whose exact color depends entirely on the viewing angle, and the object geometry.

The resulting objects look especially striking when demonstrated with the help of a mirror, because as the object turns and changes, so does the color change as well. You can watch it all in action in the video below (embedded after the page break) which showcases quite a few different takes on the concept, so check it out to see them all.

3D printing has certainly opened up a new doors when it comes to brain-bending optical effects, like this hypnotic Moiré pattern, and perhaps dual-color filament can enhance those as well.

Continue reading “Bi-Color Filament Kicks 3D Printed Optical Illusions Up A Notch” →

HP-200LX Runs Website Like It’s The 90s

May 21, 2022 by Donald Papp 20 Comments

The HP-200LX palmtop was a fascinating machine for its time, and [Terrence Vergauwen] proves that its time is not yet over, given that one is responsible for serving up the website for Palmtop Tube, a website and YouTube channel dedicated to vintage palmtops.

All by itself a HP-200LX doesn’t have quite what it takes to act as a modern web server, but it doesn’t take much to provide the missing pieces. A PCMCIA network adapter provides an Ethernet connection, and a NAS contains the website content while networking and web server software run locally. Steady power comes from a wall adapter, but two rechargeable AA cells in the 200LX itself act as a mini-UPS, providing backup power in case of outages.

The HP-200LX was a breakthrough product that came just at the right time, preceding other true palm top computers like the IBM PC 110. In the early 90s, it was unimaginable that one could have a fully functional MS-DOS based machine in one’s pocket, let alone one that could last weeks on a couple of AA cells. It didn’t have some proprietary OS and weird ports, and that kind of functionality is part of why, roughly 30 years later, one is able to competently serve up web traffic.

A video overview of the machine and how it all works is in the video embedded below. And if you’re more interested in what an HP-200LX looks like on the inside? This video is all about taking apart and repairing a 200LX.

Continue reading “HP-200LX Runs Website Like It’s The 90s” →

TurtleAuth DIY Security Token Gets (Re)designed For Durable, Everyday Use

May 21, 2022 by Donald Papp 15 Comments

[Samuel]’s first foray into making DIY hardware authentication tokens was a great success, but he soon realized that a device intended for everyday carry and use has a few different problems to solve, compared to a PCB that lives and works on a workbench. This led to TurtleAuth 2.1, redesigned for everyday use and lucky for us all, he goes into detail on all the challenges and solutions he faced.

When we covered the original TurtleAuth DIY security token, everything worked fantastically. However, the PCB layout had a few issues that became apparent after a year or so of daily use. Rather than 3D print an enclosure and call it done, [Samuel] decided to try a different idea and craft an enclosure from the PCB layers themselves.

The three-layered PCB sandwich keeps components sealed away and protected, while also providing a nice big touch-sensitive pad on the top, flanked by status LEDs. Space was a real constraint, and required a PCB redesign as well as moving to 0402 sized components, but in the end he made it work. As for being able to see the LEDs while not having any component exposed? No problem there; [Samuel] simply filled in the holes over the status LEDs with some hot glue, creating a cheap, effective, and highly durable diffuser that also sealed away the internals.

Making enclosures from PCB material can really hit the spot, and there’s no need to re-invent the wheel when it comes to doing so. Our own [Voja Antonic] laid out everything one needs to know about how to build functional and beautiful enclosures in this way.

Natural Language AI In Your Next Project? It’s Easier Than You Think

May 18, 2022 by Donald Papp 25 Comments

Want your next project to trash talk? Dynamically rewrite boring log messages as sci-fi technobabble? Happily (or grudgingly) answer questions? Doing that sort of thing and more can be done with OpenAI’s GPT-3, a natural language prediction model with an API that is probably a lot easier to use than you might think.

In fact, if you have basic Python coding skills, or even just the ability to craft a curl statement, you have just about everything you need to add this ability to your next project. It’s not free in the long run, although initial use is free on signup, but for personal projects the costs will be very small.

Basic Concepts

OpenAI has an API that provides access to GPT-3, a machine learning model with the ability to perform just about any task that involves understanding or generating natural-sounding language.

OpenAI provides some excellent documentation as well as a web tool through which one can experiment interactively. First, however, one must create an account and receive an API key. After that is done, the doors are open.

Creating an account also gives one a number of free credits that can be used to experiment with ideas. Once the free trial is used up or expires, using the API will cost money. How much? Not a lot, frankly. Everything sent to (and received from) the API is broken into tokens, and pricing is from $0.0008 to $0.06 per thousand tokens. A thousand tokens is roughly 750 words, so small projects are really not a big financial commitment. My free trial came with 18 USD of credits, of which I have so far barely managed to spend 5%.

Let’s take a closer look at how it works, and what can be done with it!

Continue reading “Natural Language AI In Your Next Project? It’s Easier Than You Think” →

Web Emulator For The Kenbak-1 Computer (If You’ve Heard Of It)

May 7, 2022 by Donald Papp 16 Comments

Ever heard of the KENBAK-1? Recognized as the first personal computer, created by John Blankenbaker and sold in 1971 in comparatively small numbers, it’s now a piece of history. But don’t let that stop you if you are curious, because of course there is an emulator on the web.

If the machine looks a bit strange, that’s because early computers of this type did not have the kind of controls (or displays) most people would recognize today. Inputs were buttons and switches, and outputs were lights showing binary values of register contents. The machine could store and run programs, and those programs were entered in pure machine code (no compiler, in other words) by setting individual bit values via the switches. In fact, the KENBAK-1’s invention preceded that of the microprocessor.

The KENBAK was the first electronic, commercially available computer that was not a kit and available to the general population, but the story of how it came to be is interesting. Back in 2016 we covered how that story was shared by John Blankenbaker himself at Vintage Computer Festival East.