A developer could hack into the Apple Lightning to HDMI dongle and run Doom directly on the accessory. According to nyan_satan’s comments in the YouTube video (h/t MacRumors), the $49 Apple Lightning Digital AV Adapter features a custom Samsung SoC with a 400MHz ARM Cortex-A5 core and 256 MiB of DRAM.
The dongle should be enough to run Doom, which requires a 386 processor and 4MB of RAM. Apple put an SoC inside the dongle because the USB 2.0 protocol that Lightning used did not have the bandwidth required to run HDMI. So, it compressed the data from the Lightning device and then used the chip inside the adapter to decompress it for viewing on HDMI displays.
The adapter runs a simplified version of iOS, but since it doesn’t have persistent storage, the developer used their MacBook to load firmware with a file system. They also use the laptop's connection for controls, but aside from that, everything runs directly on the dongle.
Although Doom runs well already, nyan_satan said the game has yet to hit 60 FPS on the dongle with proper resolution. However, reimplementing the function that populates frames into the framebuffer can vastly improve performance, allowing the game to reach the desired quality on the Apple accessory.
The developer said he plans to release the software behind this Doom project as a package in the future, allowing anyone with a jailbroken iOS device to run it and try it for themselves. In the meantime, he plans to improve it further, like introducing sound output and finding a way to attach a controller to the dongle so you can play Doom without needing a Mac.
Doom is popular among many enthusiasts and developers, with the “But can it run Doom?” becoming a fun challenge to port the old game from 1993 to just about anything. And with the increasing power of chips, even the ones found in adapters and accessories, many people are finding ways to do just that. We’ve seen the game run on the Nintendo smart alarm clock and on a neural chip that uses just one mw, and we’ve also encountered ports of the game on the most unexpected of places, like a Microsoft Word document, a PDF file, and even a Captcha.
