A while ago I took a couple of casual looks into the the format of the PS2 Memory Card images created by PCXS2. My initial thoughts were pretty basic and my follow up identified the basics of the format and also mentioned the ECC bytes I mistook for a regular checksum, thanks to alkarl and Matt for the corrections.

The other week I wrote out the code in Delphi to check and update the ECC sections and was set to delve into the format wholeheartedly. Until I found that Ross Ridge had been there and completed the work already!

Ross has put the information into the public domain, anyone interested should take a look at his excellent technical breakdown of the PlayStation 2 Memory Card File System and also give mymc, a tool for working with PCXS2 Memory Card images, a try.