The Tragic Demise Of The Technirama Prism-Based Anamorphic Lens

March 7, 2026 by Maya Posch 5 Comments

A commercial Delrama prism-based anamorphic lens for large cameras. (Source: Mathieu Stern, YouTube)

Although to the average person a camera lens is just that bit of glass you stick on the front of the camera to make stuff appear in focus, there’s a whole wide world out there of lens designs and modifications with enough variety to make your head spin. Some of these designs make a big impact, while others fade away again, sometimes at the whims of film makers and photographers. Prism-based anamorphic lenses are an oddity that recently [Mathieu Stern] got his hands on. (Video, embedded below.)

During the 1950s and 1960s there was a bit of a competition between anamorphic formats, which use special lenses that ‘squeeze’ a larger image so that widescreen movies could be recorded on standard 35 mm film. By using the same lens for recording and playback, the result was a mostly distortion-free image. Here the Technirama format by Technicolor who teamed up with Dutch company De Oude Delft (‘Old Delft’) to produce the prism-based Delrama lenses that fit on existing lenses for cameras and projectors.

The last gasp of the Delrama anamorphic lenses. (Credit: Mathieu Stern, YouTube)a

Despite having a clearly superior, distortion-free image than the cylindrical lenses of the competition, Technirama got pushed out of the commercial market, leaving De Oude Delft to try and interest the consumer market for Delrama with 8 and 16 mm adapters. These latter are the ones that [Mathieu] got his hands on and tried out with a DSLR camera.

Troublesome with these Delrama adapters is that their silver mirrors tend to degrade over time, and they also turned out to be rather fragile, which are both things that made consumers sour on them. Another challenge was the fixed four meter focus that’s great when you’re using it with a projector, but terrible for up-close shots. All of these issues resulted in Delrama fading from the market by the 1970s until all that remains are these remnants of a format that once was used to film some of the biggest Hollywood movies.

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Fixing An Onkyo Receiver With Multiple Faults

March 7, 2026 by Maya Posch 10 Comments

Modern-day receivers are miracles of digital audio and video processing, but compared to their more analog brethren, they can come with a host of new and fascinating faults. The Onkyo TX-SA806 and SR806 receivers were released back in 2008, with [Tony359] recently getting the latter variant in for repair. Described as having weird digital distortion on the audio outputs, this particular issue got fixed by recapping the PCB with all the digital processing in the first video on this receiver, but this left the second issue unaddressed of a persistent hum, which is the topic of the second video on this repair.

Capacitor C5662 in the Onkyo TX-SR608 receiver with a slight bulge. (Credit: Tony359, YouTube) — Capacitor C5662 in the Onkyo TX-SR608 receiver with a slight bulge.

With the easy fix of recapping of the digital board already tried, next was a deep-dive into the receiver’s schematics to figure out where this low-frequency hum was coming from. With it sounding very much like mains frequency hum bleeding through, this was the starting point. Presumably somewhere on the power rails the normal filtering had broken down, so all rails had to be identified and checked for this interference.

With ripple on the 10V and 12V rails as well as the others seemingly in order, it wasn’t clear where the 100 Hz hum was coming from, but people on the BadCaps forum offered some help. After some back and forth it was deduced that the problem was the +15 VA rail, with heavy ripple on it due to a dead capacitor on the +22 V rail that comes straight from a transformer.

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How An Old Automatic Stoker Was Hacked Onto A Modern Lancashire Boiler

March 6, 2026 by Maya Posch 3 Comments

Usage of an automatic stoker. (Source: Claymills Pumping Station, YouTube)

Hacks are of all ages, with the Victorian-era Claymills Pumping Station being no exception. When its old Lancashire boilers from the 19th century were finally replaced with modern 1930s boilers, the 1920s-era automatic stokers were bodged onto the new boilers with a rather ill-fitting adapter plate, as there was no standard Lancashire boiler design. Nearly a hundred years later it was up to the volunteers at this Victorian-era pumping station to inspect and refurbish this solution, before fitting it back onto the boiler.

Lancashire boilers have two flue channels in which the coal is burned, which used to be done purely by hand. The automatic stokers are belt-driven devices that continuously add fresh fuel and massively lighten the workload. The 1920s stokers are still in place at this pumping station and a feature that they would love to retain.

Thus, after previously pressure-testing this #1 boiler to well beyond its operating pressure, the refurbished adapter plate was mounted back on with some percussive persuasion of the ‘very large beam’ variety.

Before the stokers could be mounted again, however, the boiler inspector had to give his OK to put the brickwork around the boiler back in place which helps to insulate it, among other functions. Once this is completed the boiler can finally see a fire again since it was last used in the 1970s. Whether these vintage stokers will work flawlessly will remain a surprise until then, but it’ll be a treat to see them operate.

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The World’s Smallest Marble Clock With Pick And Place Arm

March 6, 2026 by Maya Posch 12 Comments

Clocks come in many styles and sizes, with perhaps the most visually pleasing ones involving marbles. Watching these little spheres obey gravity and form clearly readable numbers on a clock has strong mesmerizing qualities. If you’re not into really big marble clocks, or cannot quite find the space for a desk-sized clock, then the tiny marble clock by [Jens] may be an option.

While he totally loved the massive marble clock that [Ivan Miranda] built, it is a massive contraption that’s hard to justify as a permanent installation. His take on the concept thus makes it as small as possible, by using a pick-and-place style arm to place the marbles instead. Although the marbles don’t do a lot of rolling this way, it’s decidedly more quiet, and replace the rumbling and click-clacking of marbles with the smooth motion of a robotic arm.

Another benefit of this clock is that it’s cheap to make, with a price tag of less than $23. A big part of this is the use of cheap SG90 micro servos, and a permanent magnet along with a mechanism that pushes the marble off said magnet. Perhaps the biggest issue with this clock is that the arm somewhat obscures the time while it’s moving around, but it’s definitely another interesting addition to the gallery of marble clocks.

We have previously seen such clocks built out of wood and brass as well as 3D-printed using pendulum mechanisms, which can be made pretty compact as well, albeit with a more analog vibe.

Thanks to [Hari] for the tip.

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Reverse Engineering The PROM For The SGI O2

March 6, 2026 by Maya Posch 9 Comments

The SGI O2 was SGI’s last-ditch attempt at a low-end MIPS-based workstation back in 1996, and correspondingly didn’t use the hottest parts of the time, nor did it offer much of an upgrade path. None of which is a concern to hobbyists who are more than happy to work around any hardware- and software limitations to e.g. install much faster CPUs. While quite a few CPU upgrades were possible with just some BGA chip reworking skills, installing the 900 MHz RM7900 would require some PROM hacking, which [mattst88] recently took a shake at.

The initial work on upgrading SGI O2 systems was done in the early 2000s, with [Joe Page] and [Ian Mapleson] running into the issue that these higher frequency MIPS CPUs required a custom IP32 PROM image, for which they figured that they’d need either SGI’s help or do some tricky reverse-engineering. Since SGI is no longer around, [mattst88] decided to take up the torch.

After downloading a 512 kB binary dump of the last version of the O2’s PROM, he set to work reverse-engineering it, starting by dissembling the file. A big part of understanding MIPS PROM code is understanding how the MIPS architecture works, including its boot process, so much of what followed was a crash-course on the subject.

With that knowledge it was much easier to properly direct the Capstone disassembler and begin the arduous process of making sense of the blob of data and code. The resulting source files now reassemble into bit-identical ROM files, which makes it likely that modifying it to support different CPUs is now possible with just a bit more work.

For those who want to play along, [mattst88] has made his ip32prom-decompiler project available on GitHub.

Thanks to [adistuder] for the tip.

Top image: Silicon Graphics 1600SW LCD display and O2 workstation. (Source: Wikimedia)

California’s Problematic Attempt To Add Age-Verification To Software

March 5, 2026 by Maya Posch 87 Comments

Last year California’s Digital Age Assurance Act (AB 1043) was signed into law, requiring among other things that operating system providers implement an API for age verification purposes. With the implementation date of January 1, 2027 slowly encroaching this now has people understandably agitated. So what are the requirements, and what will its impact be, as it affects not only OS developers but also application stores and developers?

The required features for OS developers include an interface at account setup during which the person indicates which of the four age brackets they fit into. This age category then has to be used by application developers and application stores to filter access to the software. Penalties for non-compliance go up to $2,500 per affected child if the cause is neglect and up to $7,500 if the violation was intentional.

As noted in the Tom’s Hardware article, CA governor Newsom issued a statement when signing the unanimously passed bill, saying that he hopes the bill gets amended due to how problematic it would be to implement and unintended effects. Of course, the bigger question is whether this change requires more than adding a few input fields and checkboxes to an OS’ account setup and an API call or two.

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Prevent Your Denon Receiver Turning On From Rogue Nvidia Shield CEC Requests

March 5, 2026 by Maya Posch 15 Comments

In theory HDMI’s CEC feature is great, as it gives HDMI devices the ability to do useful things such as turning on multiple HDMI devices with a single remote control. Of course, such a feature will inevitably feature bugs. A case in point is the Nvidia Shield which has often been reported to turn on other HDMI devices that should stay off. After getting ticked off by such issues one time too many, [Matt] decided to implement a network firewall project to prevent his receiver from getting messed with by the Shield.

The project is a Python-based network service that listens for the responsible rogue HDMI-CEC Zone 2 requests and talks with a Denon/Marantz receiver to prevent it from turning on unnecessarily. Of course, when you want these Zone 2 requests to do their thing you need to disable the script.

That said, HDMI-CEC is such a PITA that people keep running into issues like these over and over again, to the point where people are simply disabling the feature altogether. That said, Nvidia did recently release a Shield update that’s claimed to fix CEC issues, so maybe this is one CEC bug down already.