AWJ has recently implemented a core for the cpu v25/35 nec, thanks to this has been emulated the sound in batsugun

Batsugun does not use the feature of the CPU to encode the opcode using a conversion table

Unfortunately kbash, vfive, and dogyuun fixeight you.

Analyzing the code but 'you can see huge similarities with the Code of batsugun and this has enabled me to decipher and AWJ most of fully equipped opcode. The first result is that the conversion table for kbash, vfie dogyuun and is identical. In addition, the code and batsugun kbash is almost one hundred percent identical. In addition, the startup code of dogyuun, vfive fixeight and is identical. For the last 3 had to be more work because many have not been matched with opcode batsugun. Once decrypted opcode but these 'I noticed that the code for these three starup and decrypts copy ram content in Roma. Sucessivamente passes control to this new code, and again you start to see huge similarities between all 5 games.

Summary:

batsugun can decrypt kbash (almost identical code)

kbash allows you to decrypt and vfive dogyuun (same conversion table)

vfive dogyuun and allow to decrypt fixeight (code almost identical but different conversion table)

Once finished you can try to decrypt an implementation of the sound.









Source: mamedev.emulab.it/robiza