In this respect, the Mac OS X users may actually be better off than PC users, as the source code for the STIR42xx drivers for Mac OS X are available. I picked the source code up from this site (thanks

Last night, I tried using an open-source project called "rs400" to transfer data from my RS800CX. I got this to work, eventually, by inserting a small delay in the program. The data transfer was quick and unproblematic, but "rs400" cannot parse the data correctly - mainly because the RS800CX was introduced after "rs400" was written.
I've looked, but I cannot find any documentation from Polar on the data structures transferred between the watch and the computer. Does anybody have any information to share?