Адаптер для MAPLE (RELEASE)

[SWAT]

(19.02.2023 22:25)Falco Girgis писал(а):  

(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.

Thanks for this info!
Perhaps in this way they laid a reserve in case there is a batch of bad memory, or vice versa, during development there were problems with it, and then they disappeared.

I would like to take this opportunity to ask and I will be glad for any help.
How does the DC determine that a VMU is inserted? I did emulation in the ISO Loader (only memory of course), but the games don't see the VMU, although I can change the Maple data flow.
The VMU emulation is almost complete, but it still is not possible to use it.
I set a bit in the response address of the controller frame, but the game still does not want to send commands to the VMU until I physically insert it. And I act during a Maple DMA interrupt before control is given to the game. I can't figure out where I'm wrong.