do cheats that modify the program space memory's rom work with street fighter iii3?

[insertnamehere]

Hello,i am asking this question because i wanted to reverse engineer the sequence format, i have now the midi parts done (but i suck at reverse engineering, so the staff at vgmrips did all the actual reverse engineering)
the region between 06788000 and 0678803f contain data about instruments, but it can only be accessed by cheats that edit the memory
i have trouble using cheats that work in the "sh2:program space memory", tried to do "maincpu.mb@6788140 = 39", but it never worked for me... mame gives always the message "error in assignement expression : unknown symbol", and i wanted to know why mame is not accepting it, is it because its not implemented in mame yet?
thanks for the help...

Edit: i am using mame 1.91, if this problem is not present in earlier or newer versions of mame, that would be great...

[Pugsy]

Yes, you need to write to the opcode region 'o'. There's an example of one in the sfiii3 cheat file.

Code: Select all

  <cheat desc="Hit Anywhere"> <comment>Turn on before the first match for it to work!</comment>
    <script state="on">
      <action>temp0 =maincpu.ow@608E97E</action>
    </script>
    <script state="run">
      <action>maincpu.ow@608E97E=0009</action> <!-- This ROM cheat was made by nolberto82 -->
    </script>
    <script state="off">
      <action>maincpu.ow@608E97E=temp0 </action>
    </script>
  </cheat>

[insertnamehere]

thanks pugsy for your response

i have tried optocode cheats in the instrument region from 6788000 to 678c000(fox example, maincpu.ob@06788140=0x33) while i was inside of the sound test, but i cannot hear any difference...
and this happens in the song data and sample data too...
i have made 2 videos as proof, but i don't know if these are clear enough... https://bit.ly/2r6QmjA

also, i feel like i need to explain what is going on with these addresses (im not that great at explanations... this one is only a really quick overview, i would like to know if i cloud post a more in depth explaination)
so, from 06788000 to 0678C000, there is the instrument data,
from 0678c000 to 0678f000 is all sample information, like the key, the start offset, and end offset,
and at 0678f000 is the start of the sequence data...

[Pugsy]

It's an odd one for sure.

The Hit Anywhere cheat needs to be turned on before the first match for it to work...

Might it work ingame (not sound test) as long as you enable it as soon as you can and leave it on?

Be sure to use it as a cheat though, as the o region gets overwritten quite often and the cheat will keep poking it back.

Code: Select all

  <cheat desc="Test">
    <script state="run">
      <action>maincpu.oq@06788140=3333333333333333</action>
      <action>maincpu.oq@06788148=3333333333333333</action>
      <action>maincpu.oq@06788150=3333333333333333</action>
    </script>
  </cheat>

Worth a shot i guess?

It's worth noting that you should use the standard cheat engine rather than the plugin one, as the o region isn't being poked with that as the Hit Anywhere cheat doesn't work.

[crazyc]

It's worth noting that you should use the standard cheat engine rather than the plugin one, as the o region isn't being poked with that as the Hit Anywhere cheat doesn't work.

Fixed.

Edit: The opcode space likely won't work for changing the midi data because it's data and opcode space is only valid for instruction opcode fetches. The read/write data for the 0x06000000 region comes from the encrypted simms. which aren't available to debugger expressions. You can do potentially do this with the cheat plugin, if you really want this I can do it for you, but as noted the simms are encrypted which means you'd have to encrypt your data first for the game to be able to read it properly.

[insertnamehere]

Thanks crazyc, i deduce you are a former mame developer...

i did not know that there was a bug with the "hit anywhere" cheat.
pugsy, tried to do what you said, but its not working...
and crazyc, i would like very much an help for modify the simm data, or to know how exacly the encrypted data is turned into normal data and viceversa...

[crazyc]

I can help with the cheat engine part, the encryption is outside my skill set.

[insertnamehere]

ah, ok...
so, in the cheat, i can target one memory region, like "maincpu.mb@6788140 = 39" targets the maincpu region, but then there are memory spaces that have names with periods, slashes, and every kind of punctuation, and the simm files have a memory space with a period, i would like to know if there is a way to write the cheat so that it can target memory regions with names with punctuation.

[crazyc]

The simm only sets you can use simmx.x.mb where x.x are the slot numbers (in theory, this might not work because of the period in the name) to set a byte in the rom. For the sets with a cdrom, there's no way to edit the simm data with the built in cheat engine. You'd have to use the Lua cheat engine, with modification, to change bytes in the simms.

[insertnamehere]

ah, so is there a mod availablefor the lua cheat engine, or if you cloud make it?
i can't make it myself, i have no expirience in lua...

Edit: sorry if, before i edited this message, i gave the impression in wich i seemed to ignore the fact that you had the capabilities to mod the lua cheat engine...