I started out trying to write the image to a Patriot 256GB SD and realized it wouldn’t fit, so I decided to instead use a Patriot 512GB SD so I could at least see if I liked it before either shrinking or getting a Samsung 256GB SD. I briefly tested on the 512GB SD, checked a few games, configured some controllers, seemed OK.

Then I started working on removing some games and shrinking the image, came up with a shrinked image I thought was good, but when I played it I had problems. One of which was Rambo II on Sega Master System, graphics were all messed up. I assumed I had somehow screwed up the shrinking process.

So I decided to just buy a Samsung SD that would fit the original image, and I used Rambo II on Sega Master System as my quick test after writing. Graphics still messed up, now I’m confused. I re-download the original image from scratch to make sure it’s not just a corrupt file but I get the same problem again.

Now an obvious answer would be the Samsung card is somehow bad, but I tested it multiple times with 2 tools, it passed everything and the write speeds seemed appropriate as well. Physically it doesn’t have any markings I know of that would indicate it is counterfeit. Next would be maybe my card reader, but this same card reader has written many many images to SD cards, including the original image on the 512GB SD that seems to work fine.

I can’t figure it out.