When I bought a second-hand Psion 3a 512k earlier in 1997, I was impressed with its capabilities. After writing Win32 programs it's refreshing to write a "Hello World" program that doesn't use 1.5 MB of disk space!
On this page you'll find links to programs that I have written for the Psion in OPL. They are all available for download.
This is the first OPL program I wrote. It doesn't do much; it converts Arabic numbers to Roman numerals and vice versa.
This little program allows you to convert from Ordnance Survey Grid co-ordinates to latitude/longitude and vice versa. Now supports OS Sheet identifiers and six figure references.
This may be of interest to any amateur astronomers out there. It has two display modes to show various different times such as Sidereal Times, and apparent times. Updated to show Modified Julian dates.