yesterday i released a new version of my GBA dumping program that now "officially" supports YJencrypted dumping (it's been on an experimental branch for ages) https://github.com/tzlion/vfdump and also documented the extremely tedious process for dumping those carts https://github.com/tzlion/vfdump/blob/master/YJDumping.md
new blogpost! I took a closer look at MMC/SD history, and the deeper I dug, the less truth I found in the common factoid that βSD happened because companies wanted a card with DRMβ - to a point where Iβd like to dispute it in general.
read it here: https://sdomi.pl/weblog/21-nobody-knows-what-happened-at-mmca/