Some of our readers probably remember that in mid-2021, an enthusiast named Josh Max took a CaptionCall landline phone and used it to run a special Doom build. Today it's Parker Reed's turn, but he decided to go one step further: he configured the numeric keys as controls, and the handset to shoot. Rip and Tear… even though there's no dial tone. (?)
Many users on the web are wondering if it's time to look for another game beyond Doom to turn into a "Hello World". After all, the available documentation is huge, and if the device lacks the necessary hardware resources, today there are several options within our reach to compensate for that deficit.
I imagine that sooner or later we'll see another title under a similar treatment (the first Quake, maybe? Unreal? Half-Life?), but until that happens… today we return to a hack we can already consider classic: Doom on a landline phone. What's interesting about it? Video below:
Running and playing Doom on a landline phone
The phone in question is a CaptionCall, usually distributed in the United States under subsidy programs, and intended for people with hearing loss. A significant number of these phones have appeared in second-hand stores and online platforms at very reasonable prices (between $20 and $30). The hardware inside (one of the models has an ARMv7 i.MX6 SoC, 1 GB of DDR3 RAM, and 4 GB of solid-state storage) makes it an excellent development system, but Parker Reed on YouTube decided to add an extra twist.
If my eyes don't deceive me, in the video you can see a Debian installation with PrBoom Plus running the Freedom pack, but there's more: Parker can play using the numpad, and the switch to hang up the handset works as a trigger. He also mentions that he tried to configure the phone's volume as a strafe control to avoid attacks with lateral movements, but it doesn't work correctly.
In a previous video, Parker installed a copy of Rockbox to take advantage of the integrated audio. An important detail is that the sound card is not really connected to the phone, and it only intercepts one of its lines for the subtitling service, but there's a 2.5 mm auxiliary output, and all it needs is to connect a speaker. The panel's refresh rate is 75 Hz, while the touchscreen responds at 120 Hz. In other words, there's good hardware inside that phone, and if you can get one, don't hesitate.
Source: Hackaday
