Because I am curious, I looked at the nba pbp code and found something interesting.
the main game code is encrypted. It is decrypted and copied into ram at runtime. Also, the decryption relies on the previously decrypted byte to decrypt the following.
So you cannot patch the encrypted game code. If you do, you have to decrypt it, patch it, and encrypt the whole code to make it work.
Also, I found that nba play by play only requires 0xf7 data from serial eprom handler at boot time.
After that it looks it doesn't care.
Since I have no means to update the serial eprom, I managed to get the main code patched to avoid checking it at boot time.
It looks to run fine in mame. Will look later if it works on my board so I can play to it again...
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Re: New revision for nba play by play ?
