This is the first program I wrote for the Psion, it is dialog based. It's sole purpose is to convert numbers between their Arabic (1,2,3,4...) form to the Roman form (I,II,III,IV…) and vice versa.
It should run on the 3a, 3c and Sienna. Would anyone who bothers to port it to the Series 5 please email me with the modified OPL and OPA and I'll post them here.
Download Roman: ROMAN.OPA
Download the source: ROMAN.OPL