For beginner to read and write entire EEPROM in a loop with I2C,
Change configuration settings that can not normally be accessed.

For me (USB Dual SATA Dock), I wanted to turn off the port multiplier
so it could boot from either HDD port, but also in that mode,
only one drive can be mounted at a time.

The problem that was resolved is,
two dual boot computers with three different op systems that
do not all agree with each other's file systems.
I wanted to turn drives off individually (to prevent them going nuts)
depending on the op system being run currently,
but without having to pull the drives out physically all the time.
There are many possible configurations achieved by either pulling pins,
or changing EEPROM locations.