loading binary double from atari

Ok, this is going to be hard to explain:

I am currently writing a piece of software on the PC that has to be able to read old datafiles that were written with a C program on an Atari Falcon030.

Problem 1 was that I had to do a byte-swap. This was rather straight-forward, so now I can read shorts and longs ok.

Problem 2 is that I still can't read double values! Somehow it seems these are either nog in IEEE format or something else went wrong. I cannot 'recreate' the numbers in any other way, so I need to be able to convert the values from the original datafile..

Somehow I think somebody must have run into a problem like this with converting files from Unix or something...

Please, can anybody here help me with problem 2?