Know Audio: Lossy Compression Algorithms And Distortion

October 28, 2025 by Jenny List 37 Comments

In previous episodes of this long-running series looking at the world of high-quality audio, at every point we’ve stayed in the real world of physical audio hardware. From the human ear to the loudspeaker, from the DAC to measuring distortion, this is all stuff that can happen on your bench or in your Hi-Fi rack.

We’re now going for the first time to diverge from the practical world of hardware into the theoretical world of mathematics, as we consider a very contentious topic in the world of audio. We live in a world in which it is now normal for audio to have some form of digital compression applied to it, some of which has an effect on what is played back through our speakers and headphones. When a compression algorithm changes what we hear, it’s distortion in audio terms, but how much is it distorted and how do we even measure that? It’s time to dive in and play with some audio files. Continue reading “Know Audio: Lossy Compression Algorithms And Distortion” →

A 3D Printed 16mm Movie Camera

October 27, 2025 by Jenny List 4 Comments

The basic principles of a motion picture film camera should be well understood by most readers — after all, it’s been well over a hundred years since the Lumière brothers wowed 19th century Paris with their first films. But making one yourself is another matter entirely, as they are surprisingly complex and high-precision devices. This hasn’t stopped [Henry Kidman] from giving it a go though, and what makes his camera more remarkable is that it’s 3D printed.

The problem facing a 16mm movie camera designer lies in precisely advancing the film by one frame at the correct rate while filming, something done in the past with a small metal claw that grabs each successive sprocket. His design eschews that for a sprocket driven by a stepper motor from an Arduino. His rotary shutter is driven by another stepper motor, and he has the basis of a good camera.

The tests show promise, but he encounters a stability problem, because as it turns out, it’s difficult to print a 16mm sprocket in plastic without it warping. He solves this by aligning frames in post-processing. After fixing a range of small problems though, he has a camera that delivers a very good picture quality, and that makes us envious.

Sadly, those of us who ply our film-hacking craft in 8mm don’t have the luxury of enough space for a sprocket to replace the claw.

Continue reading “A 3D Printed 16mm Movie Camera” →

Exploding The Mystical Craftsman Myth

October 27, 2025 by Jenny List 85 Comments

As a Hackaday writer, I see a lot of web pages, social media posts, videos, and other tips as part of my feed. The best ones I try to bring you here, assuming of course that one of my ever-vigilant colleagues hasn’t beaten me to it. Along the way I see the tropes of changing content creator fashion; those ridiculous pea-sized hand held microphones, or how all of a sudden everything has to be found in the woods. Some of them make me laugh, but there’s one I see a lot which has made me increasingly annoyed over the years. I’m talking of course about the craftsman myth.

No. The Last True Nuts And Bolts Are Not Being Made In Japan

If you don’t recognise the craftsman myth immediately, I’m sure you’ll be familiar with it even if you don’t realise it yet. It goes something like this: somewhere in Japan (or somewhere else perceived as old-timey in online audience terms like Appalachia, but it’s usually Japan), there’s a bloke in a tin shed who makes nuts and bolts.

But he’s not just any bloke in a tin shed who makes nuts and bolts, he’s a special master craftsman who makes nuts and bolts like no other. He’s about 120 years old and the last of a long line of nut and bolt makers entrusted with the secrets of nut and bolt making, father to son, since the 8th century. His tools are also mystical, passed down through the generations since they were forged by other mystical craftsmen centuries ago, and his forge is like no other, its hand-cranked bellows bring to life a fire using only the finest cedar driftwood charcoal. The charcoal is also made by a 120 year old master charcoal maker Japanese bloke whose line stretches back to the n’th century, yadda yadda. And when Takahashi-san finally shuffles off this mortal coil, that’s it for nuts and bolts, because the other nuts and bolts simply can’t compare to these special ones. Continue reading “Exploding The Mystical Craftsman Myth” →

Windows 95, With Just A Floppy Drive

October 26, 2025 by Jenny List 45 Comments

It’s something of a shock to be reminded that Microsoft’s Windows 95 is now 30 years old — but the PC operating system that brought 32-bit computing to the masses and left behind a graphical interface legacy which persists to this day, is now old enough that many in the community have never actually seen it. The original requirements were a 386 or better, 4 megabytes of memory, and a hard drive. [Robert’s Retro] is exploding one of those requirements, creating a full Windows 95 install using only a floppy drive.

As you might imagine, even if you had one of the super-rare 2.88 megabyte drives, such a feat would require a few tricks. In this case the biggest trick is the FlashPath, a curious 1990s peripheral that allows a SmartMedia card to be used in a floppy drive. With a special DOS driver it allows what is in effect a 32 megabyte floppy disk, but even that’s not enough for ’95. In come a couple of further tricks, installing Windows 95 to a compressed DriveSpace volume which is copied to the FlashPath, and copying the Drivespace volume to a RAM drive and mounting it, on boot. It needs a conventional floppy to boot before swapping to the FlashPath and it seems the copying process is extremely slow, but we’d expect Windows 95 from RAM to be very quick indeed.

There have been other minimalist Windows 95s over the years, but what makes this one unusual is that it’s a full install. Five years ago at the OS’s quarter century we took a look at it with 2020 eyes, and tried gauge its effect on modern desktops.

Continue reading “Windows 95, With Just A Floppy Drive” →

The Isetta TTL Computer Makes Some Noise

October 24, 2025 by Jenny List 5 Comments

Our Hackaday colleague [Bil Herd] is known for being the mind behind the Commodore 128, a machine which famously had both a 6502 and a Z80 processor on board. The idea of a machine which could do the job of both those processors in hardware while containing neither would have blown the mind of any 1980s computer enthusiast, yet that’s exactly what [Roelh]’s Isetta TTL computer does. It’s an extremely clever design whose targeted microcode allows the processor-swap trick, and since he’s brought it from prototype to production and has it running SymbOS since we last saw it, it’s time we gave it another look.

A diagram showing chip placement on the Isetta PCB. — All the functions on what is a surprisingly compact board.

The video below the break shows the machine in action, with the Windows 95-like SymbOS GUI running a series of sound tests in the emulated AY-3-8910 sound generator, as well as a Lemmings-like game. It also runs Sinclair ZX Spectrum software, giving it access to a huge library.

We were lucky enough to see some of this in person when we encountered it for a second time on our travels during the summer — and it’s just as impressive in the real as it looks in the video. The feeling really hits you of how this would have blown away anything on the 8-bit market in 1985, made more impressive by the silicon in use being not too far from what was available at the time.

We’re told you can now buy one for yourself as a kit, and we’re looking forward to seeing it generate an ecosystem. We’re particularly curious as to whether that retargetable microcode could allow it to support other archetctures of the day.

Our original coverage can be read here, and we’ve also touched upon SymbOS.

Continue reading “The Isetta TTL Computer Makes Some Noise” →

Tommy Flowers: How An Engineer Won The War

October 24, 2025 by Jenny List 26 Comments

Back in 2016, we took you to a collection of slightly dilapidated prefabricated huts in the English Home Counties, and showed you a computer. The place was the National Museum of Computing, next to the famous Bletchley Park codebreaking museum, and the machine was their reconstruction of Colossus, the world’s first fully electronic digital computer. Its designer was a telephone engineer named Tommy Flowers, and the Guardian has a piece detailing his efforts in its creation.

The front of the museum's Colossus MkII. — TNMOC’s Colossus MkII.

It’s a piece written for a non-technical audience so you’ll have to forgive it glossing over some of the more interesting details, but nevertheless it sets out to right a long-held myth that the machine was instead the work of the mathematician Alan Turing. Flowers led the research department at the British Post Office, who ran the country’s telephone system, and was instrumental both in proposing the use of electronic switches in computing, and in producing a working machine. The connection is obvious when you see Colossus, as its racks are the same as those used in British telephone exchanges of the era.

All in all, the article makes for an interesting read for anyone with an interest in technology. You can take a look at Colossus as we saw it in 2016 here, and if your interest extends to the only glimpse the British public had of the technology behind it in the 1950s, we’ve also taken a look at another Tommy Flowers creation, ERNIE, the UK Premium Bond computer.

British Train Departures As They Should Be Viewed

October 21, 2025 by Jenny List 33 Comments

The first generation of real-time train information screens for British railways came in the form of suspended color CRTs in familiar rounded fiberglass housings. They were a ubiquitous sight across the network for years, until of course suddenly, they weren’t. Can they be brought back? [Heliomass] has come about as close as it’s possible to be, with a modern emulation that runs from live data feeds.

The screens were recognizably using the same graphics standards as Teletext, and thus it was no surprise back in the day to see from time to time an Acorn boot screen in a railway station.

We remember some debate at the time as to whether they were running Archimedes of BBC Micro hardware behind the scenes, though it seems likely it might have been the industrial BBC Micro derivative.

The modern recreation uses an emulated BBC Micro for the signage, with a serial connection to a server component running in Python on more modern hardware. This handles grabbing the data and sending it to the Beeb for display. The result is an unexpected bit of nostalgia for anyone who spent the 1980s or ’90s in south east England.