For the past few months, my friend Tom and I have been exploring our very own corner of retro: while everyone else has been completing their Nintendo collections or running old computers on the MiSTer, we've been building an OPL runtime for iOS.
OPL (Organiser Programming Language), is a BASIC-like language that came built into all Psion handheld computers. It was crucial in helping establish a vibrant developer community and large libraries of shareware for the platform, and was the first programming language I experienced. Where computers like the ZX Spectrum introduced a slightly older generation to software development, OPL and Psion are where it all started for me.
Drawn in by the lure of a good technical challenge (and the possibility of revisiting some of our childhood software), we set about re-implementing the OPL runtime itself in a combination of Lua and Swift. Roughly three months later, we've shipped our first version. There's still some rough edges (missing opcodes amongst other things), and a lot to do, but it already runs a wide range of programs.
OpoLua is available now in the App Store, and we'd love people to try it out. It currently supports running EPOC Release 5 OPL for the Psion Series 5 and Series 7, and you can install SIS files directly, so it's easy to try out your old programs.