Nintendo DS-TV-OUT Restoration Project

Introduction

During late 2020, we discovered that the Nintendo DS Lite had a leftover feature in its SoC allowing it to easily have cheap hardware video output. With a little circuitry and some software hacks, we were able to restore it and make it usable for anyone. No FPGA’s, no bulky or cumbersome hardware. This mod is specially useful to revive consoles with only the lower screen, being able to watch the upper screen on your TV. Or to create a GBA Macro with additional TV Output.

First iteration of the TV-OUT board in action

Installation

If you are just interested in installation, this is the current method while we work on simpler methods and more features you have requested:

1. Install the flashME CFW (Custom FirmWare) on your DS Lite
2. Connect the Nintendo DS Lite’s upper screen flex to the PCB board.
3. Donwload the “NDS TV OUT ENABLE.nds” homebrew from the NDS TV OUT repo
4. Download Twilight Menu
5. Copy both the NDS TV OUT ENABLE and Twilight Menu .nds files to a flashcart.
6. Use flashme to autoboot into the flashcart. You can do this by pressing A + B + Start + Select while booting. Run Twilight menu, and from there, run the enabler homebrew.
7. The console will return to Twilight Menu. Now you can use the buttons on the board to swap between the different screen modes (Upper Screen to TV, Bottom Screen to TV, etc) and launch your games.

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Software

The retail firmware of the Nintendo DS Lite disables this specific feature early in the boot process. To reenable it, we use a custom firmware like flashme, which is very easy to install and is required only once, plus a homebrew. Despite that, we are working on an even simpler solution to make it available to as many people as possible, our own custom firmware which integrates patches to enable this feature directly on boot. Additionally, we are currently working with homebrew developers to integrate control of this new feature into existing software for the DS Lite.

Hardware

This feature is only found on the Nintendo DS Lite. Nintendo DS Phat does not contain this feature nor does the Nintendo DSi. It is important to remark that this is not the same hardware found on Devkits or other special units. This hardware feature is present in virtually every single Nintendo DS Lite out there. The reason why it was left there is unknown, but as said before, it is not related to development units, those use a different video capture hardware. Perhaps Nintendo imagined the Nintendo Switch as early as 2006?

We only need a few extra hardware components to make this video signal usable. You will be able to download the schematics and gerber files for our open hardware circuit board from the repository. The latest version is revision 1.2 which fixes some minor issues with a component in the board.

First prototype and tests before designing a proper board

The final, production-ready board contains a DAC (Digital to Analogue Converter) which turns the 10 bits digital signal at 16.7 MHz provided by the DS Lite into a proper analogue signal. This signal then goes through an operational amplifier and it’s ready to be delivered to your nearest TV trough composite video.

We are currently considering creating an additional PCB revision which would allow to install the mod on consoles without lossing a working upper screen.

from Hacker News https://ift.tt/2ZD4DW6