We generally cast a skeptical eye at projects that claim some kind of superlative. If you go on about the “World’s Smallest” widget, the chances are pretty good that someone will point to a yet smaller version of the same thing. But in the case of what’s touted as “The world’s smallest vector monitor”, we’re willing to take that chance.
If you’ve seen any of [Arcade Jason]’s projects before, you’ll no doubt have noticed his abiding affection for vector displays. We’re OK with that; after all, many of the best machines from the Golden Age of arcade games such as Asteroids and Tempest were based on vector graphics. None so small as the current work, though, based as it is on the CRT from an old camcorder’s viewfinder. The tube appears to be about 3/4″ (19 mm) in diameter, and while it still had some of its original circuitry, the deflection coils had to be removed. In their place, [Jason] used a ferrite toroid with two windings, one for vertical and one for horizontal. Those were driven directly by a two-channel push-pull audio amplifier to make patterns on the screen. Skip to 15:30 in the video below to see the display playing [Jerobeam Fenderson]’s “Oscilloscope Music”.
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.
The build relies on a lens that [Jason] salvaged from an old rear-projection TV. These units used CRTs with big lenses which projected the image onto a screen. That’s precisely what is happening here, with a vector display replacing the CRT used in the original TV. The vector display itself used here is a tube from a small black and white TV set, which [Jason] modified to use a Vectrex yoke, making it capable of vector operation.
Through some modification and careful assembly, [Jason] was rewarded with a wall-sized display for his Vectrex console. This is demonstrated with some beautiful glowing vector demos, accompanied with appropriate bleep-bloop music, as was the style at the time. The Cantina band is a particular highlight.
Judging by the projects we’ve seen before, from his tiny LED earrings to cramming a MIDI synthesizer into both a DIN plug and later a USB plug, [mitxela] likes a challenge. And while those projects were underway, the game console you’ll see in the video below was sitting on the shelf, hidden away from the world. That’s a shame, because this is quite a build.
From someone who claims to have known little about electronics at the beginning of the project, this is pretty impressive stuff. Our only quibbles are the delay in telling us about it, and the lack of an Asteroids implementation. The former is forgivable, though, because the documentation is so thorough and the project is so cool. The latter? Well, one can hope.
For Hackaday readers which might not be so well versed in the world of home video gaming before the 1983 crash, the Vectrex was an interesting attempt at bringing vector graphics into player’s living rooms. Priced around $500 in today’s dollars, the machine was unique in that it included its own black and white CRT display rather than requiring the owner to plug it into their television. To spice things up a little bit, games would include a thin plastic overlay you could put over the screen to give the game faux colors. What can we say? It was the 1980’s.
Like many vintage gaming systems, the Vectrex still commands a devoted following of fans, some of which continue to find ways to hack and mod the system nearly 40 years after its release. One such fan is [Arcade Jason], who’s recently been fiddling with the idea of creating a modern take on the overlay concept using a hacked LCD display. While it’s still a bit rough around the edges, it does hold promise. He hopes somebody might even run with the idea and turn it into a marketable product for the Vectrex community.
[Jason] started by getting an old digital picture frame and tearing it down until he liberated the LCD panel. By carefully disassembling it, he was able to remove the backlight and was left with a transparent display. He then installed the panel over the display of the Vectrex, leaving the picture frame’s PCB and controls dangling off to the side. Extending the display’s ribbon cable should be easy enough for a more robust installation.
He then loaded the frame with random psychedelic pictures he found online, as well as some custom overlays which he quickly whipped up using colored blocks in an art program. In the video after the break, [Jason] shuffles through images on the frame using the buttons on the PCB while loading different demos to show the kind of visual effects that are possible.
While a neat concept, there are a couple of issues that need to be resolved before this could really be put into practice. For one, the LCD panel isn’t the proper size or aspect ratio to match the Vectrex display, so it doesn’t cover the whole CRT. It’s also rather difficult to select images to show on the LCD panel; an improved version might use something like the Raspberry Pi to load images on the panel while exposing a control interface on a secondary screen of some type.
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.
We’re not entirely sure what to call this one. It’s got the usual trappings of a drone, but with only a single rotor it clearly can’t be called by any of the standard multicopter names. Helicopter? Close, but not quite, since the rotor blades are fixed-pitch. We’ll just go with “monocopter” for now and sort out the details later for this ducted-fan, thrust-vectored UAV.
Whatever we choose to call it — builder [tesla500] dubbed it the simultaneously optimistic and fatalistic “Ikarus” — it’s really unique. The monocopter is built around a 90-mm electric ducted fan mounted vertically on a 3D-printed shroud. The shroud serves as a mounting point for the landing legs and for four servos that swivel vanes within the rotor wash. The vanes deflect the airstream and provide the thrust vectoring that gives this little machine its control.
Coming to the correct control method was not easy, though. Thanks mainly to the strong gyroscopic force exerted by the rotor, [tesla500] had a hard time getting the flight controller to cooperate. He built a gimballed test stand to work the problem through, and eventually rewrote LibrePilot to deal with the unique forces on the craft and tuned the PID loops accordingly. Check out the results in the video below.
Some attempts to reduce the number of rotors work better than others, of course, but this worked out great, and we’re looking forward to the promised improvements to come.