In the years since then there have been a couple of revisions to the standard, SDHC, and SDXC, which have given us the huge cards we are used to today. Many other devices from the 2Gb SD era ...

Two formerly reserved bits are used to indicate card type to the host, with standard SD cards using a value of 0, with a 1 indicating SDHC format (or later, SDXC). Sharp readers will note that ...