Ok I'm looking at someone else's code which uses a lot of this:
/* initialize SPI with lowest frequency; max. 400kHz during identification mode of card */
SPCR = (0 << SPIE) | /* SPI Interrupt Enable */
(1 << SPE) | /* SPI Enable */
(0 << DORD) | /* Data Order: MSB first */
(1 << MSTR) | /* Master mode */
(0 << CPOL) | /* Clock Polarity: SCK low when idle */
(0 << CPHA) | /* Clock Phase: sample on rising SCK edge */
(1 << SPR1) | /* Clock Frequency: f_OSC / 128 */
(1 << SPR0);
SPSR &= ~(1 << SPI2X); /* No doubled clock frequency */
Does anyone know of a good reference for this stuff?
Once I know how to convert it to Arduino style code, I should be dumping data from a SD card. 