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Flash Equipment > [F2AU] I am looking for CIZ internal info : game IDs

#28149 - Vince - Wed Oct 27, 2004 1:47 pm

Hello to you all,

I almost finished adding the F2AUltra support on if2a (Linux software). All is working fine except that CIZ, the bootloader of Ultra carts, relies on a 64KB internal block (I called it the "content descriptor") to display cart contents. This means that, even of the ROMS are correctly written to the cart (an they are :), CIZ cannot see nor boot them. Usually, the content descriptor is updated whenever an operation is performed on the cart.

I studied hexdumps of this block and already found all related fields that have to be filled/written for the content descriptor to be on par with the cart contents. These fields include release list index, saver type, ROM size, active/hidden state, etc. However, sth is still missing : Game IDs.

Game ID is displayed by CIZ when you press B after having selected a ROM (first line). This ID is used to :
1. uniquely identify the game
2. locate the game to boot (with other parameters)
3. match a compressed save with the corresponding game (CIZ says "Loading:_XXXXXXX", where XXXXX is the game ID when you start a ROM)

Could sb give me hints on how the flashing software could generate these IDs? I've already tried CRC'ing the ROM and looking in the ROM header, no luck.

Thanks for your help,

Vince

#28437 - Vince - Sun Oct 31, 2004 9:58 am

Still no reply...
From the tests I did, it seems CRC are involved : to generate GameID, Powerwriter may do a CRC on the ROM header. So my question is : what kind of CRC are used to check ROMs (CRC16, CRC32, etc).

Thanks for your help, the searches I did with keyword crc did not answer this question

Vince