Why it matters: A new iOS emulator plans to run old iOS games on modern operating systems. The HLE approach means there's no need to get and install a full iOS firmware, while app support is currently pretty basic. But developers are moving fast on that front.

There's a new iOS emulator in town, and it wants to bring 32-bit gaming apps back into a working state on modern machines and operating systems. touchHLE is specifically designed to run games "from the early days of iOS," with a focus on iPhone/iPod touch apps for iPhone OS 2.x. In its current state, however, the emulator doesn't even support touch controls, at least not yet.

Born as a "full-time passion project" by a single developer in December 2022, touchHLE is radically different from traditional low-level emulators (like QEMU) as it is based on a "high-level emulator" design: the program's simulated CPU only runs the code from an app binary and some needed iOS libraries. touchHLE takes the place of iOS, the developers explain, providing its own implementations of the system framework components like Foundation, UIKit, OpenGL ES, OpenAL, etc.

The first release of touchHLE supports x86-64/x64 versions of Windows and macOS, while there is no official support for Linux environments yet. As for Apple Silicon Mac users, the x64 macOS build of the emulator reportedly works under the Rosetta compatibility layer.

In its current state, touchHLE doesn't even have a GUI and it works with mouse+keyboard or joypad controls alone. App support is limited to a single, unencrypted game, namely Super Monkey Ball, which was an App Store launch title in 2008. The game is full playable already, with working graphics, sound effects and music, save game persistence, a consistent 30 fps frame rate even on a "fairly underpowered" Retina MacBook laptop from 2017.

The emulator also provides some "prettification" enhancements, like the ability for the single supported game to run with increased internal resolution up to 4K (and maybe more) with no noticeable performance impact. The macOS build has a memory leak issue, though, which is wasting 0.2MB of RAM per second on macOS. This could be a problem in macOS itself, the SDL2 framework or in some other dependencies, the developers say.

The GitHub repository of touchHLE provides all the instructions needed to run the emulator and load Super Monkey Ball – minus a working ROM of the game itself, of course. Hikari_no_yume, the developer that started the project at the end of 2022, says that no promises can be made about the future or when a new release with more supported games will come out. Gamers and iOS fans will need to "be patient," the coder says.