Decoding car alarm remote

[George]

I have a mongoose remote system I'd like to decode it's used for remote central locking of cars - but I would like to use the remote for other PIC based projects - it's a neat little remote 100% waterproof and from what I crudely measured a range of around the 100m mark. I'm wondering how do get the data into something useful to the PIC the reciever board hooked to a scope looks like it reads 0.76ms and 0.38ms for 0 and 1 on a scope - the problem is I think I'll need to find a digital storage scope to figure out the nitty gritty, it's a rolling code - but I'm hoping it has an identifier and a function in it maybe at either end of the rolling code so the code is not so important as I'm not really worried about security, does anyone have any experience with these? Am I right in assuming the controller will have it's own identifier and fucntion before the rolling code? Thanks

[Ron Marcus]

A lot of the rolling code generators give you a one in 24 million chance of picking the right code on the next key press. You would be better off piggybacking a hackable receiver with the existing one. I reverse engineered a remote PIR detector once for fun. It had a 24 bit transmission, but it was not encrypted. Once you have a receiver that will pick up the 315 MHz or 433 MHz signal, you can output the data to a standard oldsillyscope. You can send the signal continuously, and record the image to graph paper. Similarly, you can adapt some of the IR decoding software for the PIC, and do it that way.
Ron