Building a so-called “Game Boy Macro” is a great way to salvage a Nintendo DS that has a broken hinge or top screen, as the system only needs the lower display to play Game Boy Advance games. Naturally, DS games that were designed to use both screens would no longer be playable. Or at least, that’s what we thought. But as [Facelesstech] shows, it’s actually possible to play DS games on a Game Boy Macro if you do a little extra soldering.
It turns out that there are two test points on the original DS motherboard where you can pick up the signal for the top and bottom screens respectively. With just three wires and a simple switch, you can select which signal gets fed into the bottom screen in real-time with no image degradation. Now, this won’t do you any good on games that make constant use of both the top and bottom DS displays, but for many titles, the bottom screen was used for little more than a map or inventory display that you only need to glance at occasionally.
With the ability to switch between them at will, a large number of DS games are perfectly playable with just one screen. Interestingly, the touch panel still works the same regardless of which video feed is being pipped in; so if you memorize which areas need to be touched to perform different actions, you don’t even need to flip the images. In the video below, [Facelesstech] demonstrates the concept with New Super Mario Bros, which would otherwise be unplayable as the action usually is shown on the top screen.
This hack is only possible because the two displays on the DS are identical beyond the touch overlay, which as we learned during a previous deep-dive into the technology behind this revolutionary handheld, was a trick Nintendo used to squeeze as much performance as they could out of its relatively meager 3D hardware. Unfortunately, it seems like the modification is much harder to pull off on the DS Lite, so it wouldn’t be compatible with the slick Game & Watch styled Game Boy Macro we covered recently.