Hi. I’m trying to write a software program to read the manufacturers data from a SanDisk SDHC 8 Gb card on a notebook or desktop. I’m particularly wanting the manufacturers serial number. The SD Card host controller I’m using is a Realtek RTS5138 driven from the USB bus. There are provisions in Microsoft’s Win API for WindowsCE (using DeviceIOControl API function) to get this data, but there doesn’t appear to be an equivalent in the desktop Win32 API. Internet forums that discuss this subject have given up trying in frustration. I have tried the WMI interface API but that also fails. What I have managed to find out is that the Realtek Host Controller driver implements an interface called the DD API (defined presumably by the SD Card Association) and specifically there are two API calls - DDGetMID and DDIdentify. These API calls are exported by the Realtek driver but there is no data published on how to call these functions. If I could find how to pass parameters, then I may be able to make a call direct to the Realtek driver and work around this major flaw in the Microsoft Win32 API. This would be very valuable for a lot of software programmers, so any help on the structure and parameters for these two API calls would be very welcome.