Reverse-Engineered GBA Board Could Come In Handy

October 25, 2023 by Lewin Day 8 Comments

Retro gear is beloved, both for what it can do, and what it reminds us of. Nostalgia is a powerful thing, after all. But then, so is corrosion — and the latter has a habit of killing hardware and driving up prices for remaining units. Thankfully, hard workers like [NatalieTheNerd] are out there, creating reproduction PCBs to keep old hardware alive. Her Game Boy Advance (GBA) reproduction PCB is a great tool for the restoration and modding communities.

The board was reverse engineered, with [Natalie] sharing various scans and schematics of the GBA’s motherboard on the Modded Game Boy Club website. The project recreates the AGB-CPU-03 version of the GBA, and is designed to be produced on a 1 mm board with an ENIG process. You can combine the PCB with some salvaged parts and a new shell and build yourself a remarkably fresh GBA, if you so desire.

Beyond it’s intended use, [Natalie] points out the board outlines could be used as a basis for RetroPie or ESP32 projects that fit into a standard Game Boy Advance form factor. We love that idea. We’ve seen [Natalie’s] work before too, in the form of this neat little macropad. Nifty as always!

Can An 8-Bit Light Gun Work On A Modern TV?

October 17, 2023 by Jenny List 55 Comments

It’s an accepted part of retro gaming lore, that 8-bit consoles perform best when used with an original CRT TV. One of the reason for this is usually cited as being because the frame buffer and scaler circuit necessary for driving an LCD panel induces a delay not present on the original, and in particular this makes playing games which relied on a light gun impossible to play. It’s a subject [Nicole Branagan] takes a look at, and asks whether there are any ways to use a classic light gun with a modern TV.

Along the way we’re treated to an in-depth look at the tech behind light gun games, how the gun contained a photodiode which on the NES was triggered by the brief showing of a frame with a white square where the target would sit, and on the Sega consoles by a white screen with an on-board timer counting the screen position at which the gun was aimed.

The conclusion is that the delay means you won’t be playing Duck Hunt or Hogan’s Alley on your 4K TV, but interestingly, all is not lost. There are modified versions of the games that take account of the delay, or an interesting lightgun emulator using a WiiMote. We’d be happy at playing either way, just as long as we can take pot-shots at the annoying Duck Hunt dog.

Light gun image: Evan-Amos, Public domain.

Super NES Cartridge Pulls A Sneaky, Plays Minecraft

August 31, 2023 by Donald Papp 24 Comments

Sometimes it’s the little touches and details that make a project. That’s certainly the case with [Franklinstein]’s Super Nintendo (SNES) Cartridge Hard Drive. It might only be an enclosure for a solid-state hard drive with a USB interface, but the attention to detail is what really makes it worth checking out.

A SNES cartridge has a pretty standard clamshell-ish construction, but fitting the solid-state drive plus cable adapter turned out to be a bit of a challenge.

Since [Franklinstein] wanted the cartridge to look as original as possible, careful measuring and cutting was needed to securely fit the drive and provide an unobtrusive USB-C port tucked discreetly into the cartridge’s opening. We like the technique of using a 3D printed fixture to take up the slack on the cable by exactly the right amount, resulting in a 100% rattle-free end product. A custom Minecraft sticker label provides the finishing touch.

Being able to plug it into a computer and actually play Minecraft is a neat gimmick, but it really shows that some careful construction and assembly can be what makes something look like a clean build instead of a hack job. Take a look at additional build detail and pictures, and check out the video of the build, embedded below.

Hey, if sneaky cartridge mod tricks intrigue you, then you’ll absolutely want to check out how it was possible to play DOOM on a NES from a cartridge. Maybe that’s the next evolution for a cartridge with a Minecraft label on it?

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Automation For The NES

August 15, 2023 by Bryan Cockfield 11 Comments

Old hardware might not be anywhere close to as powerful as modern technology, but it does have a few perks. Aesthetics can of course drive the popularity of things like retro gaming systems, but the ease of understanding the underpinnings of their inner workings is also critical. The Nintendo Entertainment System, now nearly four decades old, is a relatively simple machine by modern standards and this lends the system to plenty of modifications, like this controller that allows the system to be somewhat automated.

The original NES controller used a fairly simple shift register to send button presses to the system. The system outputted a latch signal to the controller, the shift register would take as input the current state of the buttons, and then would send them one-by-one to the system at a rate of around 1000 times per second. These signals can be sent without a controller easily enough, too. This build uses a CD4021 shift register, which is the same as the original controller, but instead of reading button states it accepts its inputs from a separate computer via a latching circuit. In this case, the separate computer is a custom design that came about through adapting cassette storage for a 6502-based computer, but it could come from anything else just as easily.

With this system in place, it’s possible to automate gameplay to some extent. Since the system can’t get feedback about the game in its current state, it requires some precise timing to get it to play the game well, and a lot of tuning needs to go into it. This isn’t just a one-off, either. Similar methods are how we get tool-assisted speedruns of games and although these are often done in emulators instead of on real hardware, they can result in some interesting exploits.

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Super Mario In Sed, Sort Of

August 9, 2023 by Dave Rowntree 7 Comments

We definitely needed to reach for a sed reference guide for this one, but looking at the animated GIF of the script running, it is recognizably Super Mario Bros. albeit with minimal gameplay beyond jumping obstacles and avoiding or destroying koopas et al. Creator [Ivan Chebykin] is for certain a master of the dark arts.

Digging in a bit deeper, it’s not strictly speaking 100% sed. A wrapper shell script is required to interface to the shell and grab the keyboard input to pass along. This is simply because sed is a stream processor, and as such it requires text to be fed into it, and it produces a text output. It has no way of reading the terminal input directly, hence the wrapper script. However, all the game logic and ‘graphics’ rendering is pure sed, so that’s perfectly reasonable.

Such programming demos are a great way to hone the finer points of various tools we use every day, whilst not being serious enough to matter if we fail. Pushing the boundaries of what can be done with these basic nuts and bolts we take for granted, is for us the very essence of software hacking, and bravo we say.

Reckon you could top this? Show us! In the meantime, here’s a guide to hacking the recently released Game and Watch, and then doing the decent thing and running DOOM on it. Finally, sed is notoriously tricky to work with, so to help here’s a graphical debugger to make things a little clearer.

Adapter Lets Digital Gamepads Work On The Tandy Color Computer

June 22, 2023 by Lewin Day 2 Comments

The Tandy Color Computer came with analog joysticks, quite unlike most computers and consoles of the early 1980s. Many games of the era actually worked best with digital input, so [Gadget Reboot] whipped up a converter board to allow Nintendo gamepads to work with the computer.

The build relies on an earlier breakout board that [Gadget Reboot] built in order to read early Nintendo gamepads and output a digital 5 V signal. Meanwhile, the Tandy Color Computer is expecting variable o-5 V signals from the X and Y axis pots in its standard joysticks. To convert the gamepad button presses into voltages for the CoCo, the build uses a CD4066 analogue switch IC. When no controller buttons are pressed, the 4066 is set up to output 2.5 V on both the X and Y axes. Pressing up or down, or left or right on the D-pad, outputs 0 V or 5 V respectively as required. This essentially lets the controller’s D-pad act as a digital joystick for a computer that never actually had one.

It’s a neat hack that might make playing certain games on the Color Computer significantly easier. It’s also just neat to interface a different controller to the old hardware. In the early 80s, computers were simple enough that this could all be achieved with a minimum of dumb circuitry.

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Zelda Guardian Sculpture Tracks Humans And Pets Via Camera

June 3, 2023 by Lewin Day 3 Comments

In The Legend of Zelda: Breath of the Wild Guardians are a primitive form of sentry turret that tracks the player with a watchful eye. Inspired by this, [npentrel] decided to whip up one of her own in the real world.

The build relies on a Raspberry Pi kitted out with its usual camera for machine vision purposes. It uses the Viam robot toolkit, which runs a machine learning model to detect pets and humans on the camera feed. The guardian then tracks any pets or humans that show up by turning its head, and thus the camera, with a servo controlled by a PWM signal via the Raspberry Pi’s GPIO pins. It’s all wrapped up in a nicely-decorated 3D printed model that really does look like something straight out of Breath of the Wild.

Sentry projects are a great way to learn about electronics, mechanics, and image processing techniques. It’s funny to see how advanced and complicated these projects were fifteen years ago, compared to how easy they are today with modern machine learning libraries. How times change!