% language=us runpath=texruns:manuals/ontarget \startcomponent ontarget-fairphone \environment ontarget-style \startchapter[title={\LMTX\ on a phone}] When my FairPhone~2 started to get issues (running hot and then rebooting) and some spare parts became hard to get, I moved on to a FairPhone~4. We're talking early 2022. The specifications of that little computer, which comes with a 5 year warrantee and long term support are quite okay: a 1080x2340 pixel display, a Qualcomm SM7225 Snapdragon 750G (Octa|-|core (2x2.2 GHz Kryo 570 & 6x1.8 GHz Kryo 570), an Adreno 619 GPU, 8GB memory. an 256GB solid state disk, the usual phone gadgets like audio, camera, wireless, bluetooth and gps, and an USB Type-C 3.0 connector with support for OTG and DisplayPort. Why do these specification matter? One reason is that in the compile farm we generate binaries for ARM processors and this phone has a decent one. The fast cores are in the same league as an over|-|clocked RaspberryPi~4 that we use in the compile farm for generating 32~bit binaries; the 64~bit binaries are generated in a virtual machine on a Mac Mini. So, in 2023, when looking at that phone, I wondered if we could run \LMTX\ on it. I installed the UserLand \LINUX\ stub from the Android Playstore and got myself an Ubuntu headless installation. After downloading the \LMTX\ installer indeed I could install the distribution on the little machine. A next step was trying to connect the phone to the display on my desk and after getting the right USB|-|C cable from the local computer shop I managed to get a bit larger terminal although Android~12 seems not able to use the whole 4K screen. Putting it in developers mode made it possible to enable the Android desktop interface in an external monitor. A bluetooth keyboard and mouse completed the setup. Later I tried a \LINUX\ desktop but that was quite a disappointment so more research is needed there. A predictable next step was to see if I could compile the \LUAMETATEX\ source that is part of the installation. Installing \GCC\ and \CMAKE\ was easy and indeed compilation went pretty well after that. A quick performance test showed that making a format, which includes generating the file database, initially takes 10~seconds but less that 4~seconds once files are cached. Processing 1000 paragraphs from the \type {tufte} sample file is done with a reasonable 55~pages per second. I didn't test more complex documents but that might happen later, when the dock that I ordered has arrived, and when I have a decent display setup. Given the fact that I only use a handful of applications on the laptop one can wonder when the moment is there that a properly dockable phone can do the job. Of course a disadvantage is that batteries are too small so one needs to provide power, but one needs a monitor, keyboard and mouse anyway. Wear and tear of the \SSD\ can also be an issue but when storage is plenty that should work out all right. Of course it also assumes a stable operating system with one's favourite editing platform and viewer available. \stopchapter \stopcomponent