(14.01.2023 12:42)SWAT писал(а): (14.01.2023 03:11)Skarfais писал(а): Что значит 2) Можно разблокировать экстра блоки в VMU?
У VMU используется не вся память, 200 блоков это 512*200=102400 байт, но размер памяти у VMU равен 131072 байт (128 Кбайт).
Почему-то Sega решила оставить часть свободной, может что-то хотела с этим сделать не знаю.
Hey guys, sorry, English speaker here, but Google Translate has allowed me to follow along with this thread just fine, and I wanted to share some info, because I've done a lot of VMU work for ElysianVMU.
I forgot which Sega document described it, but the original intention of the unused extra storage space on the VMU was so that if any of the flash blocks become worn out and go bad after repeated use, the user data region could be extended to use some of the reserved blocks to compensate.
From some of the Sega docs I was able to find that there's supposed to be a third reserved value for entries into the FAT table, in addition to the two everyone knows about:
Код:
#define VMU_FLASH_BLOCK_FAT_UNALLOCATED 0xfffc
#define VMU_FLASH_BLOCK_FAT_LAST_IN_FILE 0xfffa
A damaged block
should theoretically have a FAT value of:
Код:
#define VMU_FLASH_BLOCK_FAT_DAMAGED 0xffff
This information was based on I believe libShinobi headers. I'm not positive whether the actual implementation ever actually marked bad flash blocks in the FAT table and extended the user space or not, but that was the original intention behind the extra storage.