Author: Bryan Cockfield

1901 Articles

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

October 28, 2026 by 4 Comments

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.

2026 Hackaday Retrocomputing Contest

Hacking The Modern Tamagotchi With UART

October 28, 2026 by 7 Comments

Although not technically the first virtual pet, the Tamagotchi handhelds certainly popularized the idea and made it a worldwide phenomenon. In the late 90s it was hard to go out in public and not see them dangling from backpacks and belt loops. They turned out to be more than a passing fad, too. There have been Tamagotchis in various forms since then, and one of the latest, the Tamagotchi Paradise, is uniquely hackable thanks to this custom UART interface.

The build starts with a simple and inexpensive CH340G UART adapter with a built-in USB interface. A custom 3D printed enclosure is used to house the adapter and also help to expose the interface to the Tamagotchi. This is done by wiring three pins to nickel strips, which are threaded through slits in the case and looped back around to create a pogo-style adapter for the Tamagotchi’s custom dock. Normally this would be used to link to other Tamagotchis, but in this case the USB-to-UART adapter mimics it, allowing for all kinds of in-game shenanigans. The project’s creator [Squalius] shows it off by connecting it directly to a browser tool in Google Chrome.

Not only that, but this can also be used to modify the software running on the handheld entirely, with the video showing demos playing not only Super Mario but also DOOM (of course). This isn’t too surprising given that these games are built with modern 32-bit ARM microcontrollers. For the 90s purists, though, it probably won’t surprise anyone to know that these devices have been the subject of various hacks almost since they came out.

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Arduino Engine Runs Many Games

October 26, 2026 by 4 Comments

A few years ago, [Smashcat] ported a ZX Spectrum game called Manic Miner to the Arduino Uno. The Arduino has less memory than the original Spectrum did, so doing all this on an 8-bit microcontroller was no easy lift. Since then, parts of this original port have been adapted to produce a game engine, allowing [Smashcat] to port several other games to the Arduino Uno as well.

The engine is able to host a 2D map with the ability to scroll, at a resolution of 256×256, as well as up to nine sprites at the same time. The graphics are locked to 50 FPS, but only with a real Arduino Uno that has a crystal oscillator. Some replica boards do not have a timekeeping chip accurate enough to replicate the video signal, which is done without a framebuffer. That signal, as well as two PWM audio channels, are still generated directly as well, with only a few resistors needed to hook everything up to a monitor and a controller, including the option of using an NES controller.

With all of that running on the Arduino and it hooked up to the daughterboard that provides the controller interface as well as the resistors for the video signal to function and a driver for a speaker, the system now runs the original Manic Miner as well as three other games: Scramble, Space Invaders, and Pac Man.

The engine and the rest of the code are available on a GitHub page as well, and there’s even a WebAssembly version available to run various pieces of the software without the specific hardware. The original ZX Spectrum was an interesting machine too that still inspires builds like this, despite it being well over 40 years old now.

Hiding Virtualization From Other Software

October 26, 2026 by 18 Comments

The Kernel-based Virtual Machine (KVM) allows Linux systems to function as hypervisors without needing any extra software, but VMs created with it don’t behave exactly like real hardware does. Sometimes that’s important, though, so [sandwich] built a tool called vfio-native that obscures the fact that software might be running in a virtual machine.

There are plenty of the ways that virtual hardware differs from bare metal. The VM may behave slightly differently for obscure instructions in ways that are measurable, it may take slightly longer to perform some tasks, or the hypervisor may simply announce itself directly. vfio-native includes some kernel patches that solve some bugs which address the different behaviors, changes the way that the kernel identifies itself, and attempts to force the CPUs to behave in ways that real hardware would behave. With all of this applied to the virtual machine, it scores a 1/85 against a VM detection tool, with a standard KVM virtual machine scoring 10/85.

For anyone looking to test this out, it’s available in the AUR for Arch Linux. Also, it’s probably worth mentioning that there are more reasons to use this than cheating at Counter-Strike. For example, security researchers testing malware need to know how that software behaves when it thinks its on real hardware, and some may behave in benign ways when confined to virtual machines. Some licensed software also may disable itself when it detects its running in a VM, which can be a nuisance for things like software controlling industrial tools which only run on operating systems that are no longer maintained or hardware that can’t be found anymore. Some other tools we’ve seen before perform similar tasks as well.

Simple, Reliable RF Remote Control

October 25, 2026 by 29 Comments

Some of the first remote controls available to consumers used sound, visible light, or even just wires to communicate with their parent device. It was many years between these first rudimentary remotes before they standardized around infrared or RF signaling. Even then it was a while before remote controls were reliable enough to not have to think about anymore. They’ve gotten so good now that there are small modules available that let us quickly build these devices to perform all manner of tasks.

[Igor Brichkov] is demonstrating this project because his garage door remote control suddenly stopped working. The RF receiver and transmitter circuits are readily available and inexpensive, but they need some support circuitry to work properly. The transmitter is paired with an encoder which is provided a binary code by wiring various pins to power and ground. This “code” is sent to the receiver which has a decoder and listens for that specific code. When the codes match it changes the state of one of its pins, which is used in this case to short the garage door’s remote terminals and signal it to open the door.

Although the resulting handheld remote with its single button looks a bit like something from 1950s science-fiction, it’s an effective solution. Especially when compared to possibly trying to reprogram a proprietary remote, find one from a company that doesn’t exist anymore, or rebuild one that operates on a bizarre frequency. With access to the physical hardware, it turns out a lot of things are controlled by just shorting pins together, and anything can do that from wires to RF transmitters.

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2026 Retrocomputing Challenge: I Would Do Anything For Serial Data

October 24, 2026 by 11 Comments

These days we take high-speed networking for granted, but it can be difficult to get vintage computers talking to modern machines. To help solve this problem [jaime] came up with Meatloaf which can provide files to a Commodore regardless of their location or medium of storage.

Meatloaf is an ESP32 device at its core, which plugs in to any of several Commodore computers through their IEC serial port. Many similar systems exist to bridge the gap between the modern world and the now-retro one, but this one connects to a dedicated service which points towards files no matter where they’re stored. There is some local storage, but it can also retrieve files from any active URL, and Meatloaf retrieves the files and then sends them to the Commodore over that serial link.

Part of what makes this unique is that the user doesn’t need to configure Meatloaf in any particular way, everything is done from the Commodore as long as the URL is known to the user. The system can even parse nested files like archive file types and send them along to the computer just like it would if they were on a period-correct floppy drive. There’s a GitHub project page as well for anyone looking to get into the weeds of this serial data interface.

2026 Hackaday Retrocomputing Contest

Using An Unmodded GBA As A Music Synth

October 23, 2026 by 5 Comments

The style and sound of older video games is unique enough that they’re still copied in relatively modern games like Undertale, Celeste, or Shovel Knight. There’s also a vibrant chiptune community making music on the older hardware directly. Often this involves hardware modding or otherwise finding chips from older gaming systems to replicate that unique retro gaming sound authentically. But disassembling older systems is not always necessary. Take a look at this Game Boy Advance synthesizer which uses the GBA hardware with no modifications at all.

The key to making this work is the GBA’s multiboot feature, which allowed these systems to send executable code over a link cable to other consoles which didn’t have cartridges. This meant that friends could play multiplayer games without each one needing their own cartridge, but it also means that nowadays people can send their own custom software directly to the console’s RAM without much extra effort. To run the synthesizer software, the GBA is connected to a computer, the software is started, and then when the GBA is powered on the snythesizer is automatically loaded into its RAM. The audio output is played over the headphone jack, and various controls are available on the computer and on the console.

In the video linked below, [Andy] is using the GBA with some other musical hardware and the sounds he’s getting from the unmodified console are impressive. It could certainly be a go-to for anyone interested in getting started in this style of music or who doesn’t want to do something like take apart an original Sega Genesis for the audio circuitry.

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