Author: Al Williams

4225 Articles

From PostScript To PDF

April 24, 2025 by 35 Comments

There was a time when each and every printer and typesetter had its own quirky language. If you had a wordprocessor from a particular company, it worked with the printers from that company, and that was it. That was the situation in the 1970s when some engineers at Xerox Parc — a great place for innovation but a spotty track record for commercialization — realized there should be a better answer.

That answer would be Interpress, a language for controlling Xerox laser printers. Keep in mind that in 1980, a laser printer could run anywhere from $10,000 to $100,000 and was a serious investment. John Warnock and his boss, Chuck Geschke, tried for two years to commercialize Interpress. They failed.

So the two formed a company: Adobe. You’ve heard of them? They started out with the idea of making laser printers, but eventually realized it would be a better idea to sell technology into other people’s laser printers and that’s where we get PostScript.

Continue reading “From PostScript To PDF” →

C64 Assembly In Parts

April 23, 2025 by 19 Comments

[Michal Sapka] wanted to learn a new skill, so he decided on the Commodore 64 assembly language. We didn’t say he wanted to learn a new skill that might land him a job. But we get it and even applaud it. Especially since he’s written a multi-part post about what he’s doing and how you can do it, too. So far, there are four parts, and we’d bet there are more to come.

The series starts with the obligatory “hello world,” as well as some basic setup steps. By part 2, you are learning about registers and numbers. Part 3 covers some instructions, and by part 4, he finds that there are even more registers to contend with.

Continue reading “C64 Assembly In Parts” →

China Hosts Robot Marathon

April 20, 2025 by 11 Comments

China played host to what, presumably, was the world’s first robot and human half-marathon. You can check out the action and the Tiangong Ultra robot that won in the video below. The event took place in Beijing and spanned 21.1 km. There was, however, a barrier between lanes for humans and machines.

The human rules were the same as you’d expect, but the robots did need a few concessions, such as battery swap stops. The winning ‘bot crossed the finish line in just over 160 minutes. However, there were awards for endurance, gait design, and design innovation.

Continue reading “China Hosts Robot Marathon” →

Open Source DMR Radio

April 19, 2025 by 4 Comments

While ham radio operators have been embracing digital mobile radio (DMR), the equipment is most often bought since — at least in early incarnations — it needs a proprietary CODEC to convert speech to digital and vice versa. But [QRadioLink] decided to tackle a homebrew and open source DMR modem.

The setup uses a LimeSDR, GNU Radio, and Codec2. There are some other open DMR projects, such as OpenRTX. So we are hopeful there are going to be more choices. The DMR modem, however, is only a proof-of-concept and reuses the MMDVMHost code to do the data link layer.

[QRadioLink] found several receiver implementations available, but only one other DMR transmitter — actually, a transceiver. Rather than use an AMBE hardware device or the potentially encumbered mbelib codec, the project uses Codec2 which is entirely open source.

There’s a lot of explanation about the data collection to prepare for the project, and then a deep dive into the nuts and bolts of the implementation. You might enjoy the video below to see things in action.

If you just want to listen to DMR, it’s easy. If Codec2 sounds familiar, it is part of M17.

Continue reading “Open Source DMR Radio” →

Hackaday Podcast Episode 317: Quantum Diamonds, Citizen Science, And Cobol To AI

April 18, 2025 by 1 Comment

When Hackaday editors Elliot Williams and Al Williams need a break from writing posts, they hop on the podcast and talk about their favorite stories of the past week. Want to know what they were talking about? Listen in below and find out!

In an unusual twist, a listener sent in the sound for this week’s What’s This Sound competition, so it turns out Elliot and Al were both stumped for a change. See if you can do better, and you might just score a Hackaday Podcast T-shirt.

On the hacking front, the guys talked about what they hope to see as entries in the pet hacking contest, quantum diamonds (no kidding), spectrometers, and several science projects.

There was talk of a tiny robot, a space mouse—the computer kind, not a flying rodent—and even an old-fashioned photophone that let Alexander Graham Bell use the sun like a string on a paper cup telephone.

Things really heat up at the end, when there is talk about computer programming ranging from COBOL to Vibe programming. In case you’ve missed it, vibe coding is basically delegating your work to the AI, but do you really want to? Maybe, if your job is to convert all that old COBOL code.

Want to read along? The links are below. Be sure to leave your robot plans, COBOL war stories, and AI-generated Vibe limerics in the comments!

As always, the human-generated Hackaday Podcast is available as a DRM-free MP3 download.

Where to Follow Hackaday Podcast

Places to follow Hackaday podcasts:

Continue reading “Hackaday Podcast Episode 317: Quantum Diamonds, Citizen Science, And Cobol To AI” →

Linux Fu: Stopping A Runaway

April 14, 2025 by 34 Comments

The best kind of Hackaday posts are the ones where there was some insurmountable problem with an elegant solution devised through deep analysis of the problem and creativity. This is not one of those posts. I’m sure you are familiar with bit rot. You know, something works for a long time and then, for no apparent reason, stops working. Well, that has been biting me, and lacking the time for the creative, elegant solution, I decided to attack it with a virtual chainsaw.

It all started with a 2022 Linux Fu about using autokey.

The Problem

I use autokey to give me emacs-style keystrokes in Web browsers and certain other programs. It intercepts keystrokes and translates them into other keystrokes. The problem is, the current Linux community hates autokey. Well, that’s not strictly true. They just love Wayland more. One reason I won’t switch from X11 is that I haven’t found a way to do something like I do with autokey. But since most of the powers-that-be have decided that X11 is bad and Wayland is good, X11 development is starting to show cracks.

In particular, autokey isn’t in the normal repositories for my distro anymore (KDE Neon). Of course, I’ve installed the latest version myself. I’m perfectly capable of doing that or even building from source. But lately, I’ve noticed my computer hangs, especially after sleeping for a long time. Also, after a long time, I notice that autokey just quits working. It is running but not working and I have to restart it. The memory consumption seems high when this happens. Continue reading “Linux Fu: Stopping A Runaway” →

A 17th Century Music Computer

April 12, 2025 by 10 Comments

We don’t think of computers as something you’d find in the 17th century. But [Levi McClain] found plans for one in a book — books, actually — by [Athanasius Kirker] about music. The arca musarithmica, a machine to allow people with no experience to compose church music, might not fit our usual definition of a computer, but as [Levi] points out in the video below, there are a number of similarities to mechanical computers like slide rules.

Apparently, there are a few of these left in the world, but as you’d expect, they are quite rare. So [Levi] decided to take the plans from the book along with some information available publicly and build his own.

Continue reading “A 17th Century Music Computer” →