How Nintendo DS Games Will Work on the 3DS
The 3DS will be backwards-compatible with the DS’s esteemed library. There are some potential issues with this, though. How exactly will this functionality work?
Since the Nintendo 3DS was first announced in that cryptic press release back in March, it has been known that Nintendo’s latest handheld will feature backwards compatibility with legacy Nintendo DS games. It is clear from photos of the 3DS that this compatibility is achieved by means of a slot on the system that accepts both the 3DS’s tabbed cartridges as well as the older DS ones. However, nothing of this functionality is known besides the fact that it exists. How, in detail, will this feature work?
First off, it has to be clarified that any DS game that relies on an external peripheral that plugs into the GameBoy Advance slot is out, no matter what. If the slot doesn’t exist, there will be no way to plug in accessories like Guitar Hero: On Tour‘s Guitar Grip or Tony Hawk Motion‘s Motion Pack. The Rumble Pak, which is supported in a number of games, won’t be supported either, but unlike game-specific add-ons, it’s entirely optional and may even turn out to be replaced by an integrated rumble function in the 3DS, if the rumours concerning that turn out to be true.
However, one thing we can count on on is WiFi support; right from the beginning, WiFi was considered one of the original DS’s greatest selling points besides the touchscreen and the dual-screen design. Many games use it to fantastic effect—Mario Kart DS, Metroid Prime Hunters, and the Pokémon games are all prime examples—and it would be a shame for this functionality to be cut. Whatever the technical workings of the 3DS are when it comes to playing DS games (more on that further down), it is very probable that Nintendo has gone the extra mile and invested the additional effort that is necessary to support WiFi-based functions in DS games.
Fitting it to the screens
Arguably the hardest problem Nintendo will have to address with running DS games on the 3DS is the difference in screen resolution between the two devices. Both screens on all DS models feature resolutions of 256×192 pixels. The 3DS’s screens’ resolutions are 400×240 and 320×240, for the top and bottom screen, respectively. Consider both of them 320×240 for the sake of this article, though, as it is very unlikely that DS games will be stretched from their native 4:3 aspect ratio to fill the 3DS’s top screen.
Since the 3DS’s resolution is not double that of the DS’s, it’s impossible for it to simply “double the size” of every pixel of a DS game and cleanly fit it to the 3DS’s screens. This leaves Nintendo with two options for displaying DS games.
One option is for them to simply display the game’s image 1:1, at its original 256×192 resolution. On the 3DS’s screens, the neatest way to do this would look as follows:
As you can see, the image from the DS game is surrounded by black bars and pillars on all sides. This may look a little ugly, but it’s unavoidable if the 3DS is to display DS games as faithfully as possible. Note that on an actual 3DS, the image will appear to be smaller and crisper than on a DS; this is due to the 3DS’s higher pixel density.
Nintendo’s only other option is to scale the games up a bit to fit to 3DS’s higher-resolution screens. This will remove the black border on the bottom screen entirely and only pillarbox the upper screen, at the expense of image clarity.
The image will appear to be a bit blurry, but it should satisfy most of the people out there who want to play their DS games with neither black bars nor an insignificantly small image.
If you look at the two images side-by-side, you’ll notice that each has its distinct advantages and disadvantages. Which one you prefer is really a personal choice; neither I nor Nintendo can tell you which method of displaying DS games on the 3DS is the “right” way because it really depends on whether you want a “full” image or a crisper one.
I think that Nintendo will ultimately give users the choice between the two, like they did with the GameBoy Advance and its backwards compatibility with GameBoy Color games. If anyone remembers, you could choose between stretching the GBC games to the GBA’s higher-resolution screen or displaying them as-is in the middle of the screen.
Mapping the controls
Since the 3DS’s button layout differs somewhat from the DS’s, it’s important to also consider how DS games will be mapped to it. It is a given that the A, B, X, and Y buttons will stay the same (their positions haven’t changed) and the Start and Select buttons will function as before, but at their new position under the touchscreen. It also goes without saying that the touchscreen will function exactly as before; the aforementioned scaling dilemma aside, DS games that used it will continue to do so exactly the same way on the 3DS.
However, the D-pad is a point of special interest. On the 3DS, it has been moved down, closer to the bottom edge of the system, to make room for the much-loved slide pad. It’s almost guaranteed that you’ll still be able to use the D-pad for DS games, but its new position may make usage a little awkward. The slide pad is clearly the star of the show in Nintendo’s new handheld, and, having taken the DS’s D-pad’s position, brings up the question of whether we’ll be able to use it when playing DS games that weren’t originally designed for it.
If the 3DS plays DS games by means of software-based emulation (which will be discussed in detail further on), it won’t be difficult for Nintendo to remap the D-pad to the slide pad. It’s been done before with certain systems on the Wii’s Virtual Console, like the SNES and SEGA Genesis. When playing a game for one of those systems, you can use the GameCube or Classic Controller’s left analog stick instead of the controller’s D-pad. Control is not analog (meaning, pressure-sensitive) as the games were never designed for that, but it’s still a convenient option nonetheless, especially in games like Super Mario RPG: Legend of the Seven Stars that involve a lot of diagonal movement.
This is possible because the Virtual Console is a software-based emulator. There is a layer of Wii software running over the emulated game; this layer of software interprets button presses from the variety of controllers supported by the Wii and translates them into the corresponding button actions for the game that is being played. This software is also able to interpret analog stick movements and pass them on to the game as if they were D-pad presses.
It’s very probable that the 3DS will use software-based emulation to run DS games, so there is nothing stopping Nintendo from adding slide pad support to the older games. Keep in mind, though, that even if this is so, DS games will remain insensitive to how far you push the slide pad. For example, in analog stick-controlled games, pushing the stick slightly will make a character walk slowly while pushing it to its edge will have the character break into a run. On the 3DS, this gradation will not exist for DS games; pushing the slide pad further or closer will have no in-game effect.
To play DS games, the 3DS will need to emulate them. Two types of emulation currently exist, one of which the 3DS will use: hardware- and software-based emulation. Each has distinct advantages and disadvantages when used in a gaming environment; I’ve summarized them in the table below.
|Hardware-based emulation||Software-based emulation|
|maximum game compatibility||possible compatibility issues|
|controls must be mapped to a fixed set of buttons||possible to remap controls|
|more difficult to overlay system menus, etc.||emulated game can be “enhanced” by 3DS system features|
The 3DS will most likely be using software-based emulation to play DS games mainly out of cost issues; to employ hardware-based emulation, Nintendo will need to include the DS’s CPU and GPU in the 3DS, raising the price. I’ve written an accompanying article to this one that details the differences between these two methods of emulation as well as the reasoning behind my choice; you may read it here if you’re curious.
If Nintendo can overcome the potential compatibility issues that software-based emulation typically introduces, they’ll be able to use one of its greatest advantages: namely, the relative ease in overlaying the 3DS’s operating system and some of its features over DS games. The Home button, for example, has been a topic of discussion for some; I believe it will serve a function akin to the Xbox 360’s equivalent button, which allows a player to access a variety of system-wide features like the buddy system and media player in-game. If, for example, there is a persistent system-wide online system on the 3DS, while you won’t be able to use your account for DS games, you may at least be able to chat with your friends while playing them in addition to possibly playing your own music in the background. Conveniences like these would be limited only to 3DS titles if the system relies on hardware-based emulation to play DS games.
To sum everything up again, here’s a list of what we can expect when playing DS games on a 3DS:
- No peripherals and games that require the GBA slot will be supported.
- WiFi will be supported in DS games.
- Players will have the option of displaying DS games 1:1 or scaling them to fit the 3DS’s screens.
- It may be possible to use the slide pad in DS games instead of the D-pad.
- Some system-wide 3DS features may still be usable while playing DS games. Ex.: media player, tag mode, etc.
- Software-based emulation will be used to achieve DS game compatibility and enable the two points above this one to function; there is a possibility that not all DS games will be playable at the 3DS’s launch.
While it may sound like a trivial feature at first, in reality, it turns out that there are a surprising number of intricacies involved in achieving backwards compatibility with DS games on the 3DS. One has to appreciate the effort Nintendo has put into not making our old libraries of DS games obsolete just yet; it would be a shame to lose the ability to experience its wonders as the DS has often been heralded as having one of the most diverse and satisfying game libraries in history. Let’s just hope they don’t redesign the 3DS and choose to remove this sure-to-be-loved feature, as Nintendo did when they axed GBA compatibility on the DSi…