In an ancient thread, @dave mentions the frame buffer is in the data tcm area of the playdate's board. The total amount of data tcm memory dedicated to the screen should be 52 bytes per row * 240 rows = 12480 bytes (~12k) iirc. However looking at the datasheet for rev A and rev B it appears that the total amount of data tcm on both boards is >= 64k. I want to know where the rest of the tcm is being used. If it's free I want to know how to access it? Can I just read past the limits of the frame pointer?
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Okay so I was able to read a lot of the dtcm but writing seems to crash things if I write in the wrong spots. @dave is it a security issue that I can poke around the dctm? If not would you be able to give me any hints about which parts you are using and which parts we can use?
The rest of DTCM is used for other system stuff. Writing into that will likely cause crashing and unstability. There are a few chunks of unused non-TCM memory scattered about but those are effectively reserved for future expansion: If someone publishes a game that takes advantage of it we either can't add a new feature later that needs that space or we break the game.
I totally get wanting to use every part of the buffalo, but there's an unfortunate conflict here. 