As we know, the default state of erasable memory (EPROMs, NAND flash, etc) is 0xFF, but are those values what is actually exposed to the PC/device in the case of SD or CF cards? When a PC writes a file full of zeroes, is that actually writing 0x00 to the flash memory, or is it writing 0xFF?
If you were to look at a brand new SD card with a hex editor on a PC, would it be full of 0x00 or 0xFF?