Dear buton or godo,
huberrob i suggest you take a look at OpenLog SparkFun OpenLog - DEV-13712 - SparkFun Electronics this will make your life easier at some cost lol
thank you very much for this hint and I will consider to use this as a data backup.
However, as I mentioned before I intend to use a Android phone for data transmission and the SPI sensor communication seems to conflict with the USB of the Mega ADK board this was the reason why I was asking for assitance in using the 74HC125.. any advice on that would be very welcome..
best regards,
Robert