The I²C control byte (0x00 commands, 0x40 data), re-armed on every START.
Horizontal, vertical and page addressing, the column and page windows, page start and column nibbles, and display on and off.
Address 0x3C by default, or 0x3D. The 128×32 (0.91-inch) variant has the same command set with four pages.
What is left out
We list the gaps so you know when to reach for a bench.
Contrast, charge pump, multiplex ratio, display offset, clock divide, pre-charge, COM pins, VCOMH, segment remap, COM scan direction, entire-display-on and inverse. Their arguments are consumed, then they do nothing.
The model reports GDDRAM, not how the glass looks: no brightness, burn-in or current draw.