I'm delving into the historical aspects of Bitcoin's development, particularly the encoding methods used in the early .dat files created by Satoshi Nakamoto. My focus is on understanding the specific patterns and encoding schemes employed in these foundational stages, specifically the use of uppercase hex letters for blockchain data representation and two distinct patterns: "FD FE FF" and "F%F%F%".
I think the basic problem here is that you are interpreting binary data as text in cases where that is not intended.
If you want to understand the encoding methods used, then your best approach is to look at the source code.