Quick-links:
First 'proof of concept'
First Serial Data Shown
early non-inversed output
Output pin enabled 1 cycle too late
Output pin correctly enabled
Self Documenting Hardware!
Dithered characters (176, 177 and 178) don't tile particularly well on an (8+1)x9 pixel grid. I've attempted to reduce the effect by having a more 'granular' pattern, but it's not perfect.