Do you want to use a RiscOS(http://www.riscos.com/) together with your laptop, notebook, PDA or mobile cell phone? Here are links to installation or connectivity reports. You are welcome to submit your own report, too.
NetBSD/Acorn26(http://www.netbsd.org/Ports/acorn26/) is the port of NetBSD to ARMv2 and ARMv2a machines, primarily the Acorn Archimedes, A-series and R-series systems. These systems pre-date those supported by NetBSD/arm32 and use an earlier, incompatible version of the ARM architecture.ARM26 Linux (suitable for Acorn A4) http://www.mnementh.co.uk/arm26linux/ The official home of Linux for Archimedes/A30x0/A4000/A5000