A vertically stretched monochrome image of a floppy disk mahjong tile
https://digipres.club/system/media_attachments/files/114/386/266/485/080/005/original/26eb5ab217bd9202.png
it turns out they're a 6-byte header and then they're a 48x60 image, but they're vertically planar: The first row is the least significant bit, fourth row is the most significant bit, and so on.
This indexes into the palette, which is stored in PAL.CFG
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