I just realized that memc_videodma_enable never gets set to anything other than 0. It appears to be rapidly flipping between line-doubled and non-doubled mode, if that's any help. I don't have a good way of verifying that the problem is with the display and not somewhere else in the system, though, so I'm scratching my head about how to debug further. I've verified that the data from 'buffer' is getting to the texture and being drawn on the window (I can poke pixels in 'buffer' and they show up), and I've verified that it reads the CMOS. progress so far is to get it built, added a simple event loop, and it appears to run, although I seem to be running into some kind of display issue.
Thanks for the SDL update, Sarah! I've been trying to get it running on macOS.
