After having finished the design of the MLDL2000 and about to request quotes from assemblers I was pointed to the website www.mbed.org, and this is really a great product. I have made the decision to add it to the MLDL2000, instead of specialized SD card controller. The mbed controller will be able to support SD cards, and a lot more, including ethernet connectivity, serial ports and user application programming. It actually gives you a complete ARM Cortex to play with, complete with development tools, libraries and a user community online.
The only disadvantages are its somewhat higher price, and the size. Due to this size I have to redo the layout of the MLDL2000 from scratch, but it will be worth it. Imaging controlling an ethernet port from your HP41 (yes, there will be an RJ45 port on the MLDL2000 V2)!
Have a look at the mbed website, if you have any ideas let me know,
Meindert