Hey guys, i'm currently working on a project that requires additional RAM and an SD card module on my Mega 2560. My question is, because these devices need to run together, i cannot run them off the same MISO and MOSI and alternate the slave select (SS). The SD card would need to reinitialise every time... what i was thinking of doing was using the MISO/MOSI pins off the ICSP to run one of them, then use the pins 50-53 to run the other. What i'm unsure about is whether these are separate MISO/MOSI pins that will work, or if they're simply duplicated which would then cause heaps of problems.

If this won't work, does anyone know of a solution that means i can run the two devices together?

They are in fact simply a duplicate.

I don't have any experience with SD cards, but what is the problem with re-initialising? Do you have a problem with buffering?

Looks like it is bit-banging for you. Pick the slower device.

I don't think you should have to reinitialize the SD card just because you de-select it...