The reference (and others) was to the ethernet shield...
This page:
https://docs.arduino.cc/learn/programming/sd-guide/
Says this about default SPI pins:
pin 4 is default Chip Select (CS) pin for most boards
The reference (and others) was to the ethernet shield...
This page:
https://docs.arduino.cc/learn/programming/sd-guide/
Says this about default SPI pins:
pin 4 is default Chip Select (CS) pin for most boards