Yes, catymag, I agree they are wonderful tutorials and I have read them all.
BUT it still does not answer any of my questions above unless I completely missed the section you mean.
We are talking about the sdCard ID, not the gps ID. I was unable to find any information in the above links relating to how to use the sdCard ID to generate an xyz.unl file, or if the ID is in hex or decimal.
If you look at the map ID code of an img file in a hex editor the numbers are reversed. Is it the same for the sdCard ID in this software?
So what it the point of the software link provided above? Sorry but I cannot for the life of me see the connection to these issues and the tutorial links. I must be really thick!
Never mind, I guess I will have to find the answer elsewhere. Thanks anyhow for the links.