It's a picture of a chunk of memory in the Microcontroller - nibbles $60-$7F, modelled on the LCD display area in the datasheet.
It's for testing the display (see ... below ?) - bits in memory correspond to bits on the LCD screen.
It allows me to test the wiring is write by changing bits in memory without having to do it via code - just clicking on a bit toggles it and sends notification of a bit change to a listener. I can connect this to the LCD hardware and check that toggling bits here turns the right bits of LCD hardware on and off
This is one of the joys of interfaces. I have an "IHardware" interface which is basically the external bits of the microcontroller. As long as I stick with the contract it doesn't matter what's driving it or what it drives - it will work.
Hopefully :)
You may wonder with my previous Retrochallenge projects why I choose things with very limited display hardware. The honest reason is that I cannot draw for toffee :) So something with fixed or simple graphics avoids that problem. (It's part of the reason I like writing games for the Studio 2).
