2023 Hackaday Supercon Badge: Welcome To The Vectorscope

This year, the Supercon badge goes analog! (Or at least fakes it pretty convincingly.) Taking inspiration from the phosphor scopes of yesteryear, the 2023 Vectorscope badge is part analog audio playground, part art project, and all about prototyping. Who doesn’t like the warm glow and lovely green fade of an old Tektronix tube scope? That’s what we’re after.

Conceptually, the badge is two separate devices in one. Most obvious is the vectorscope, which takes in voltages in the 0 V – 3 V range and plots them out in X-Y mode in glorious fake-phosphor effect on the lovely round IPS screen. We’ve also tied an audio amplifier to the Y input that plays whatever waveform you’re watching.

But you don’t have to bring your own waveforms with you – the other half of the badge is an arbitrary programmable waveform generator that drives two channels. Off the bat, it’s configurable with the front panel controls, so you’re obviously invited to make Lissajous figures and store them in the program memories.

Combining the two halves lets you draw in voltages and time, but not until you connect them together, naturally. You see, this isn’t an analog simulation – it’s the programmable equivalent of the real deal, courtesy of the AK4619 ADC/DAC. Voltages go out on one set of pins and come back in on the other.

And you get to play around with these voltages in through-hole space too, because we’ve included a very generous prototyping board for your analog explorations. Does this instantly suggest a curve tracer to you? Be our guest! Other forms of analog video-mangling? We want to see what you come up with. Make an audio filter and watch it work on the screen in front of your very eyes.

Of course we’re not leaving you code monkeys out in the cold. MicroPython puts the “programming” in the programmable waveform generator. If you’re not content with the four stock waveforms, you’re invited to write your own. And this is where it gets artsy.

You can upload your own repetitive waveforms to the onboard direct digital synth routine, but why stop there? We’ve left most of the processing power of the underlying RP2040 untouched, for you to use. And four buttons on the front panel let you store and play back your code, so you have space to stash your demos, and a sweet joystick with a custom keycap gives you control.

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Vectrex Light Pen Works Without A Raster

Sometimes the simplest of projects end up revealing the most interesting of things, as for example is the case with [Ryo Mukai]’s light pen for the Vectrex console. It’s an extremely simple device using an integrated light sensor with built-in Schmitt trigger, but for us the magic isn’t in the pen itself but in discovering how it worked with the Vectrex’s vector graphics.

Light pens were a popular accessory in the 8-bit computing days, offering a relatively inexpensive pointing device that gave your micro an even more futuristic feel. On most computers that used a raster-scanning TV display they simply picked up the flying dot on the screen as it passed the end of the pen, but the Vectrex with its display not scanning all of the screen at once needed a different approach.

This piqued our interest, and the answer to how it was done came from PlayVectrex. There was a target X on the screen which could be picked up with the pen, and when picked up it would surround itself with a circle. Crossing the dot as it flew round the circle would tell the console where the pen was, and the position would move to fit. For those of us who only saw a Vectrex in a shop window back in the day, mystery solved! We’ve placed a video showing the process below the break.

This isn’t the first light pen we’ve seen, they can even be connected to modern computers, too.

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A multi-PCB setup to drive a CRT vector monitor

Color Vector Display Controller Brings Arcade Classics Back To Life

If you’ve been reading Hackaday long enough, you’ve probably come across a few hacks where someone made simple animations or even video games on an analog oscilloscope screen. Those hacks generally use vector graphics, where the cathode ray tube’s electron beam directly draws geometric shapes onto the screen. This gives the image a unique look that’s quite distinct from the pixel-based raster displays used on TVs and most computer monitors.

Vector displays were also used in several arcade machines of the early 1980s, including classics like Tempest, Gravitar and Star Wars. In order to emulate these games more faithfully than would be possible on a raster monitor, [Robin Champion] designed the vstcm: a color vector monitor controller to easily drive RGB vector monitors.

Star Wars (1983) displayed on CRT monitorThe design is based on [Trammell Hudson] and [Adelle Lin]’s v.st system, and therefore features a Teensy microcontroller as well as a couple of digital-to-analog converters. While the v.st can only connect to monochrome X/Y systems like oscilloscopes, the vstcm can work with RGB monitors to allow near-perfect emulation of color vector-based games. A custom software interface connects the vstcm to AdvanceMAME, a special version of the well-known arcade emulator that facilitates the connection of unusual display systems.

The end result definitely looks the part, although [Robin] notes that performance is not at the level it could be and requests those familiar with the Teensy platform to help optimize the code. If you’d like to build the vstcm but can’t find a vector monitor, you can always modify the yoke of a conventional CRT. Want to learn more about vector displays? Check out this thorough introduction.

Fake: A Laser Display Board Of Your Very Own

Update 6/23/21: Many people have called this out as fake. When viewed at 1/4 speed, you can see the logos in the YouTube video are always full-off or full-on and never caught mid way through a scanned frame. The images may be projected from off-camera to the left, rather than by the diode behind the screen. It’s a neat idea, but on closer review the demo provided smells a bit fishy so we’ve added a “Real or Fake” tag and updated the title. Update #2: [Kanti Sharma] wrote into the tipsline apologizing for the faked video, saying that he tried to get it to work but couldn’t and then “used a phone and a lens to fake the laser”. Thanks for fessing up to this one.

There are some times when an awesome project comes into your feed, but a language barrier intervenes as you try to follow its creator’s description. [Kanti Sharma]’s laser display appears to be a fantastic piece of work, but YouTube’s automatic translations in the video below make so little sense as to leave us Anglophones none the wiser as to what he’s saying. The principle comes across without need for translation though: he’s taken a laser diode module and is using it to create a vector scan by mounting it in the middle of a set of coils driven through beefy FETs by an Arduino. It’s an electromagnetic take on the same principle used in a CRT vector displays such as the famous Vectrex console, with the beam of electrons replaced with laser light.

It’s a technique not unlike what’s  been used for years in the lighting industry, in which much larger laser displays are created with mirrors mounted on galvanometers. There must be a physical limit at which the weight of the laser slows down the movement, but if the video is to be believed it’s certainly capable of displaying graphics on a screen.

People have done a lot of things with lasers on these pages, but there have been surprisingly few vector displays using them. Here’s one from nearly a decade ago.

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The Sony ScopeMan, Possibly The Best Product They Never Made

From the perspective of a later decade it’s sometimes quaint and amusing to look back at the technological objects of desire from times past. In the 1980s for example a handheld television was the pinnacle of achievement, in a decade during which the Walkman had edged out the transistor radio as the pocket gadget of choice it seemed that visual entertainment would surely follow. Multiple manufacturers joined the range of pocket TVs on offer, and Sony’s take on the format used a flattened CRT with an angled phosphor screen viewed from behind through its glass envelope. [Niklas Fauth] took one of these Sony Watchman devices and replaced its TV circuit board with one that turned it into a vector display. The Sony Scopeman was born!

The schematic is deceptively simple, with an ESP32 receiving audio via Bluetooth and driving the deflection coils through a pair of op-amps and a set of driver transistors. These circuits are tricky to get right though, and in this he acknowledged his inspiration. Meanwhile the software has two selectable functions: a fairly traditional X-Y vector ‘scope display and a Lorenz attractor algorithm. And of course, it can also display a vector version of our Wrencher logo.

We like the Scopeman, in fact we like it a lot. There may be some discomfort for the retro tech purist in that it relies on butchering a vintage Watchman for its operation, but we’d temper that with the observation that the demise of analogue broadcast TV has rendered a Watchman useless, and also with the prospect that a dead one could be used for a conversion project.

[Niklas] has had more than one project appear on these pages, a memorable example being his PCB Tesla coil.

Mac Plus Becomes A Vector Display

The vintage Macintosh all-in-one computers were a design icon, as well as being highly useful machines in the 80s and 90s. In the decades since, they’ve been used for everything from web servers to aquariums, but that’s not all. [Arcade Jason] decided to grab an old Macintosh Plus and turn it into a vector display.

The hack starts with the opening of a Macintosh, which naturally requires a long screwdriver with the right tip. Setting the stage for things to come, this is achieved by soldering together a couple of existing tools to get the reach he needs. [Jason] then proceeds to install a brightness control for the main electron gun, as well as deflection drivers and a spot killing circuit. Everything is done with the intention of the hack being reversible, as [Jason] didn’t wish to sacrifice a good Macintosh Plus just for the sake of having some fun.

For those unfamiliar with vector cathode-ray displays and the manner in which they are driven, [Arcade Jason] does a great job explaining the basics. A set of magnetic coils is used to alter the trajectory of an electron fired at the screen. If you aim those electrons in ordered lines from left-to-right, top-to-bottom you’ve created a raster display. If you instead guide the electrons to follow the shapes you want to appear on the screen you’ve created a vector display.

We can’t help but feel this would be a hilarious way to troll at a demoscene meetup. We’ve seen [Jason]’s vector work before, too — like this impressive color Asteroids hack.

Arcade Asteroids, Now In Colour

Asteroids is one of the classic games of the early arcade era. Launched in 1979 by Atari, it relied upon using an XY vector monitor to deliver crisp graphics for its space-based gameplay. One of the limitations of the original arcade games was that the game was only rendered in a single colour, white. Over 30 years later, [Arcade Jason] decided to see what it would take to build a color Asteroids machine.

The ROM hack also modified the shapes of several in-game objects.

The hack relies on the fact that the original game used a four-bit resistor ladder DAC to draw vectors in different intensity levels. Through some ingeniously simple hardware, this DAC is repurposed to denote different colours instead. It’s laced together with a 74LS08 AND gate chip, along with a handful of resistors and diodes. Three bits are used for red, green, and blue, respectively, with the fourth used as a “white boost” signal to allow the differentiation of colours like red and pink, or dark and light blue. It’s then all wired into an RGB vector monitor for final display. After that, it’s just a matter of a simple ROM hack to set the colors of various on screen objects.

Vector monitors are notoriously hard to film well, but it’s clear that in person the output is rather impressive. Making color versions of old retro games is actually a hobby of [Arcade Jason]’s – we’ve featured his color Vectrex before. Video after the break.

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