2026 Retrocomputing Challenge: Custom RISC-V Processor For Retro System

Although once little more than an academic endeavor, the RISC-V architecture is slowly supplanting applications that would have normally gone to ARM. Even a few microcontrollers have chips running this open-source instruction set now, and we expect it to grow in the future since it doesn’t require the licensing of an ARM or x86 chip. [M_Jagadeesh97] is getting ahead of the curve with this retro gaming system built on a custom-designed RISC-V system.

Most of us, presumably including [M_Jagadeesh97], don’t have access to chip fabrication tools, but what we can get is any of various FPGAs. This RISC-V CPU is built on a Terasic DE0-Nano board with 32 MB of RAM available to it, and boots to a launcher with 32 games available. There are a few limitations with this low-power system which was largely solved by limiting the display to 64×32, which lets it maintain the same aspect ratio as the original DOOM as well as the same aspect ratio for many of the older games, while still maintaining 45 FPS.

The project writeup goes deep into the design of a system like this, from the bare metal, the CPU design, the timing of the video signals, and how to implement a Wolfenstein-like raycaster. After adding a small display it looks to be fairly portable as well and is an excellent demonstration of how powerful inexpensive boards like this  FPGA can be with the proper amount of effort.

Car’s Camera Footage Backed Up To NAS

For as many sensors, cameras, and computers as there are on modern cars, they ought to be a dream to poke around in and customize to one’s liking. Unfortunately they’re generally plagued by the same locked-down, proprietary software that most consumer electronics ship with, making it very difficult to interact with these systems in ways the manufacturer doesn’t approve of. There are a few exceptions to this rule, though, and [Sasha] built this system which backs up the footage from their electric car’s on-board cameras automatically to a NAS.

The system is built around a Raspberry Pi Zero 2 W which plugs directly into a USB port in the car’s glovebox. To set it up, the software only needs to be flashed onto the Pi and then it can be controlled from a smartphone. It can connect to any NAS over a variety of protocols and keeps track of what footage has been backed up, and can even automatically restart a backup if the car drives away before it has completed. It also automatically frees up space on the car’s internal drives by deleting any files that have already been synced to the NAS. All of the data is kept in the user’s control as well, and nothing leaves the LAN unless the user sets up backups to a cloud service on their own.

If you have the correct electric car and a Pi other than a Zero 2 W, [Sasha] also has a package for other Raspberry Pis that should work. Unfortunately this was designed for a specific electric car; other makes and models won’t work with this out of the box, but we hope that won’t stop others from checking out the GitHub page anyway trying to figure out what’s going on under the hoods of their car’s electrical and computer systems. Sometimes this leads to things you might not expect, like using the car itself as a video game controller.

A Stereo Vision Board For Hardware Hackers

It’s plenty easy to do lots of vision tasks with a single camera, but using two cameras gives you lots of magical abilities, like depth perception! If you’d like to experiment with stereo vision, you might enjoy this board that [machinehum] built specifically for hackers.

The project came about because [machinehum] was particularly excited about the Rockchip RV1103, a 1.1 GHz single-core ARM chip. It comes with 64 MB of DDR2 RAM and a has a MIPI CSI-2 bus on board, which comes in handy for interfacing cameras. Thus, it was the perfect part to whip up a stereo vision board with on-board compute capability and Linux support right out of the box. The processor is paired with two OV9281 global-shutter cameras, as well as a LI2HH12 3-axis accelerometer to provide motion sensing. There’s also 4 MB of flash memory thrown on board, as well as a 10/100 Mbit Ethernet interface for good measure. [machinehum]’s write-up also lays out the software stack and how everything works in concert with Video4Linux2.

If you’re new to experimenting with stereo vision, you might find this to be a useful platform for getting started. Design files are on GitHub for the curious. We’ve seen similar projects built using the Raspberry Pi before, too, which itself is essentially just a fast ARM powered computer with useful camera interfaces built-in. Funny that.

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The World’s Smallest TV Console Plays DOOM

We’ve seen plenty of game console projects here, many of them that seek to produce a miniature game console. But this one from [RayTriangle] may break a new barrier entirely — it fits an entire TV game console that plays DOOM, including the battery, into a TV antenna plug.

There’s a type of antenna plug with screw terminals, originally intended for matching 300 ohm balanced feeder to 75 ohm co-ax. It provides a tiny project box if you look at it that way, and it’s in here that the console sits. It’s an ESP32-S3 that talks to a controller via Bluetooth, and he’s gone into some detail on how the RF for the TV is made. Some clever tricks such as a look-up table for the phase shifted chroma waveforms for each color allow the creation of a good quality composite signal through a resistor-ladder DAC, and this is modulated in a surprisingly old-fashioned way onto a carrier provided by the ESP’s clock generator.

The result as can be seen in the video below is a bit noisy, but we think that might be fixable with a little filter magic. It’s designed for PAL TVs with a VHF tuner, but we’re guessing some ingenuity could be brought into play to make it happen for UHF or NTSC. The hardware meanwhile is put on two boards either side of the battery, with a flexible PCB joining the two.

It’s true that gaming though an analogue RF input to a TV is probably less common in 2026, but we applaud the ingenuity in getting this into such a small space. For some reason it reminds us of the world’s smallest MIDI synthesizer.

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Own The OSD Chip In Your Cheap Composite Monitor

[Ogrinz Labs] has built a Robbie the Robot suit, which is super-cool, but has a huge flaw. When inside the suit, he’s too tall to do what the original Robbie actor did, which was to look through the “mouth” grille. He solved this with an inexpensive automotive reversing camera, but then realised its monitor had a built-in on-screen-display chip. After a lot of work, he’s published a GitHub repository that allows access to this thing for custom on-screen graphics.

The chip in question is an AMT630A, which contains video switching hardware, a graphics system for the on-screen-display, and an 8052 microcontroller core. He didn’t manage to get into the 8052’s brain, but the video below details the long path towards controlling it through an I2C port with an ESP32. The software is available as an Arduino library. His intention is to use it as a display for navigational sensor data to aid in maneuvering Robbie.

Given the status of Robbie as a sci-fi movie icon, it should come as no surprise that we’ve featured this suit before,

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Purely Random TV In Your Browser

One of the things we used to appreciate about broadcast television is that… you kinda just got what you got. You didn’t have to choose beyond picking a channel, and then you settled in to imbibe whatever media the CRT was spraying at you. A vague recreation of part of this experience is now available, in the form of [Sergei’s] RND.TV.

The concept is simple enough—it’s a webpage that plays random videos from The Internet Archive. Each session draws videos from a random sequence, with no algorithm or fancy social media nonsense to push some videos over others. As you might expect, you’re in for lots of random and weird stuff, from old Army videos to middle-school basketball games. You can swipe to flick to a different “channel” if you don’t like what’s playing, or you can mark videos you like if you fancied what came up in the random feed. You can also use your phone as a remote if you want to sit back and flick channels like it’s the 90s again or something.

We’ve featured other projects in a similar vein before—like little TVs from The Simpsons that play episodes on repeat. Sometimes, it’s fun to just avoid the paralysis of choice, and a random stream of content can provide that relief. Or, alternatively, you could always hook up your TV to an antenna and watch free-to-air… it’s still out there, for those that wish to view it!

Get Your Monitor Transmitting VHF With A Browser Tool

If you’re intending to transmit on the VHF band, you’re probably going to reach for a handheld or some kind of rackmount rig in your ham shack. But you needn’t bother with all that complexity, when you can use the computer on your desk to spit out such signals using a simple browser tool from [Efe].

The concept is straightforward—[Efe]’s tool manipulates pixel clocks in order to create spurious transmissions from your computer’s graphics hardware. The math pencils out pretty easily—multiply the horizontal resolution by the vertical resolution by the refresh rate, while paying attention to the precise timing of the video standard your monitor is using, and you’ve got your transmission frequency. For example, for a screen displaying 1080p at 60 Hz, with the CEA-861 timing standard, your horizontal and vertical resolutions are 2200 and 1125 respectively when paying attention to the requisite blanking intervals. Multiply those by 60 hz, and you’ll find you’re creating a signal at 148.500 MHz. Leverage this by displaying the right pattern of black and white pixels to maximise changes in voltage state on the HDMI or DisplayPort lines, and you might create a strong enough signal that you can actually pick something up. [Efe] created a tool to display these patterns to send simple Morse code messages over VHF just by flickering your screen just right.

You can test the transmitter tool for yourself here, right in your browser. You’ll want to hold your radio’s antenna nice and close to the monitor to see if you can pick up much of a signal. After all, the monitor, connectors, and cable are all built to optimize for clear signal transmission to the display, while preventing signal from leaking out to interfere with surrounding equipment.

Of course, a fair warning—you’re not supposed to intentionally transmit on bands you’re not licensed for, even if it’s incredibly weak and unlikely for anyone else to notice in a scenario like this. Still, it’s an interesting project that shows you just how electromagnetic interference can leak out of just about anything under the right conditions.