Bringing Back The CRT TV Experience In Software

November 18, 2023 by Donald Papp 44 Comments

Cathode-Retro is a collection of shaders and sample C++ code for reliving the glorious days when graphics were composite video signals displayed on a CRT screen. How? By faking it in software and providing more configuration options than any authentic setup ever had.

Love it or don’t, there’s nothing quite like it.

Not satisfied with creating CRT-style color images with optional scanlines and TV picture controls like tint and saturation, Cathode-Retro can emulate more nuanced elements as well.

The tool includes the ability to imitate things like the slight distortion of a period-correct curved screen, the subtle effects of different methods CRT displays used to actually work (such as shadow mask vs aperture grille), and even taking into account the slight distortion of light refracting imperfectly through the glass face of the CRT. There’s even options for adding noise and ghosting, which may spark some artistic ideas.

If all you need is software to recreate an old-school CRT terminal, we have you covered. But if your needs are a bit more low-level, Cathode-Retro might be what you’re missing.

OpenMV Promises “Flyby” Imaging Of Components For Pick And Place Project

November 10, 2023 by Donald Papp 8 Comments

[iforce2d] has an interesting video exploring whether the OpenMV H7 board is viable as a flyby camera for pick and place, able to quickly snap a shot of a moving part instead of requiring the part to be held still in front of the camera. The answer seems to be yes!

The OpenMV camera module does capture, blob detection, LCD output, and more.

The H7 is OpenMV‘s most recent device, and it supports a variety of useful add-ons such as a global shutter camera sensor, which [iforce2d] is using here. OpenMV has some absolutely fantastic hardware, and is able to snap the image, do blob detection (and other image processing), display on a small LCD, and send all the relevant data over the UART as well as accept commands on what to look for, all in one neat package.

It used to be that global shutter cameras were pretty specialized pieces of equipment, but they’re much more common now. There’s even a Raspberry Pi global shutter camera module, and it’s just so much nicer for machine vision applications.

Watch the test setup as [iforce2d] demonstrates and explains an early proof of concept. The metal fixture on the motor swings over the camera’s lens with a ring light for even illumination, and despite the moving object, the H7 gets an awfully nice image. Check it out in the video, embedded below.

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Bleep Remover Censors Those **** Bleeps

October 4, 2023 by Maya Posch 20 Comments

One of the more interesting cultural phenomena is the ‘bleep’ that replaces certain words in broadcasts, something primarily observed in the US. Although ostensibly applied to prevent susceptible minds from being exposed to the unspeakable horrors of naughty words, the applied 1 kHz censoring tone is decidedly loud and obnoxious enough that its entertainment level falls somewhere between ‘truck backing up’ and ‘loud claxon in busy traffic’. There is thus a definite argument to be made to censor the censoring beep to preserve one’s sanity, which is the goal of [Oona Räisänen]’s Bleep-be-gone project on GitHub.

Using a Perl-based wrapper, the versatile ffmpeg framework is used to filter a provided video that was afflicted with bleepitus, before outputting a pristine version where the infernal noise is replaced with blissful silence. This use of silence for censoring naughty words is incidentally becoming more commonplace over an ear-piercing beep, but a tool like Bleep-be-gone can be used to hasten the demise of its terror. Considering that the point of the 1 kHz back-up alarm beep is to draw a person’s attention to a piece of heavy equipment moving about, there is clearly no good reason why the replacement of a naughty word should warrant a similar drawing of attention.

Proper Video, From An ESP32

September 27, 2023 by Jenny List 19 Comments

Back in the day a miniature television, probably on a wristwatch, was the stuff of science fiction. Now, it’s something which can be done with a commodity microcontroller, as [Atomic14] shows us with the ESP32-TV that plays both video and sound. Even with modern silicon it’s still somewhat pushing the envelope.

As he explains in the video below the break, not all formats are simple enough to be decoded on the fly by a microcontroller. But he finds an AVI file to be within its capabilities which can be created with a bit of ffmpeg wizardry. The board is a fairly standard ESP32 device with an I2C bus, and the video stream isn’t too fast for this meager interface. You’ll maybe recognize the Muppets clip, but it’s possible that the early-80s BBC comedy staple The Young Ones might have passed you by if you’re not British.

We think this code is likely to be of use in quite a few projects, and it would be great to see it further refined. Small video players for not a lot of money can never be a bad thing.

Previous ESP32 video projects which have appeared on these pages have been more likely to involve driving a display directly.

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Celebrating The 6502 With Song

September 24, 2023 by Bil Herd 23 Comments

In a wonderful ode to tech nostalgia, The Taylor and Amy Show, comprised of YouTubers [Taylor] and [Amy], have released a new video “THE 6502 SONG”. This song had me singing along in roughly six clock cycles, possibly a little dancing around may have occurred as well. This isn’t just any chip they’re singing about; it’s the venerable 6502 microprocessor, the silicon heart behind iconic machines like the Apple II, Commodore 64/128, and the Atari 2600.

Their lyrics reminds me of when I lived for assembly language mnemonics and counting clock cycles, the “feeling” of a processor coming out of tristate to pronounce what it had learned in the last 500ns, and the undulations of the DRAMs like speed bumps. To top it off, portions of the song were actually recorded live at the Vintage Computer Festival Midwest 2023, where fans and computing history aficionados alike were treated to an impressive display of vintage tech.

What sets “THE 6502 SONG” apart isn’t just its catchy, melodic tune; it’s the expert blend of historical detail and genuine enthusiasm that resonates with everyone from grizzled assembly-language programmers to youngsters newly fascinated by the allure of 8-bit computing. With guest appearances from other female tech YouTubers like [Veronica Explains] and [Evie’s Revue], [AJ], [Jeri and Amy- Tilt5] and [FuzzyBad].

I believe [Chuck Peddle] father of the 6502, would be proud to see his creation live on and be appreciated so.

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An 8-bit ISA card with VGA, HDMI and composite video connectors

Upgraded Graphics Gremlin Adds HDMI Video To Vintage PCs

September 10, 2023 by Robin Kearey 34 Comments

Although new VGA-equipped monitors can still be bought, the old standard is definitely on its way out by now, being replaced by high-speed digital interfaces like HDMI and DisplayPort. It therefore makes sense to prepare for a VGA-less future, as [Yeo Kheng Meng] is doing. He designed an 8-bit ISA display card with an HDMI output that enables even the very first generation of PCs to talk to a modern monitor.

The design is based on the Graphics Gremlin by [Tube Time], which is an 8-bit ISA display card that aims to be software compatible with the obsolete MDA and CGA display formats while outputting a clean VGA signal. [Yeo Kheng Meng] modified the board by adding a TFP410 HDMI bus driver and replacing the rarely-used 9-pin RGBI connector with an HDMI version. He also updated the HDL code for the Lattice FPGA, which forms the heart of the graphics card, to account for the new digital output. While he was at it, he also added a few features he was missing in the original product, such as the option to select the color displayed in MDA mode and the ability to output both HDMI and composite video at the same time.

The video below shows the updated card in action in an IBM 5155 Portable PC. The HDMI port connects to a modern monitor, while the composite video output is routed to the 5155’s internal CRT as well as a small color monitor on top. The IBM thereby joins a small list of retro computers that have received an HDMI upgrade — the Amiga 500 and PlayStation 2 being other examples. HDMI might be a lot more complex to work with than VGA, but luckily there are open-source implementations that do much of the work for you.

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The motherboard of a Mattel Aquarius, with a small daughterboard mounted on top

Adding Composite Video To The Mattel Aquarius

September 8, 2023 by Robin Kearey 14 Comments

In the home computer market of the 1980s, there were several winners that are still household names four decades later: the Commodore 64, the Apple II and the Sinclair Spectrum, to name a few. But where there are winners, there are bound to be losers as well – the Mattel Aquarius being a good example. A price war between the bigger players, combined with a rather poor hardware design, meant that the Aquarius was discontinued just a few months after its introduction in 1983. However, this makes it exactly the type of obscure machine that [Leaded Solder] likes to tinker with, so he was happy to finally get his hands on a neat specimen listed on eBay. He wrote an interesting blog post detailing his efforts to connect this old beast to a modern TV.

The main issue with the Aquarius is that it only has an RF video output, which results in a rather poor rendition of its already very limited graphics capabilities. Luckily, there is a fix available in the form of a composite A/V adapter that’s an almost plug-and-play upgrade. The only thing you need to do, as [Leaded Solder] illustrates in his blog post, is open up the computer, desolder the RF modulator and solder the A/V adapter in its place. Getting to that point was a bit tricky due to heavy EMI shields that were fixed in place with lots of solder, requiring liberal use of a desoldering iron. Continue reading “Adding Composite Video To The Mattel Aquarius” →