using a cha256/512 board to replace a cha42g-3 board?

[marcao_cfh]

Hello everybody. How's going?

I have a question regarding a cartridge repair. I got a Samurai Shodown cartridge and the CHA board is oxidated. And I also have two cheap games with a bad NEO-PCM I hope I can use the CHA board to repair this SS cartridge. My plan is to remove all ROMs from the SS oxidated board and put them on a good board. The thing is SS uses a CHA42G-3 and the other two games uses a CHA256 and a CHA512Y.

While I know you can swap different boards, I still don't have this much knowledge on how to properly do it. I know jumpers may be properly set, but what got me confused was the CHA42G-3 description on NeoGeoDev on how the C data is organized (C1 having not C1 data but instead first 1MiB of C1 + first 1MiB of C3...).

So, this means C ROMs were built different for CHA42G boards and can't be used on other boards, or is there a way to use a CHA256/512 board to repair this SS cartridge?

I know SS is a common game that some may say it may not worth the trouble to repair it, but I don't have a working one in my collection yet and have those two spare CHA boards, and also can take the chance and learn a bit more on board swaps.

 

[pierpa86]

i think you can swap CHA 42G-3 with CHA256 but for sure not with a 512Y
Check the offset, its ok you can.

Viewpoint using CHA42G
    <dataarea name="sprites" size="0x600000">
<rom loadflag="load16_byte" name="051-c1.c1" offset="0x000000" size="0x100000" crc="d624c132" sha1="49c7e9f020cba45d7083b45252bcc03397f8c286" />    <!-- CXK381600 -->
<rom size="0x100000" offset="0x400000" loadflag="continue" />
<rom loadflag="load16_byte" name="051-c2.c2" offset="0x000001" size="0x100000" crc="40d69f1e" sha1="ec4a13582772594957f927622d50f54b0dfcd8d8" />    <!-- CXK381600 -->
<rom size="0x100000" offset="0x400001" loadflag="continue" />
    </dataarea>


Samurai Shodown
  <dataarea name="sprites" size="0xa00000">
               <rom loadflag="load16_byte" name="045-c1.c1" offset="0x000000" size="0x200000" crc="2e5873a4" sha1="65c74c1e2d34390666bbb630df7d1f4c9570c3db" />    <!-- TC5316200 -->
                <rom loadflag="load16_byte" name="045-c2.c2" offset="0x000001" size="0x200000" crc="04febb10" sha1="16a8cbf0fd9468e81bf9eab6dbe7a8e3623a843e" />    <!-- TC5316200 -->
                <rom loadflag="load16_byte" name="045-c3.c3" offset="0x400000" size="0x200000" crc="f3dabd1e" sha1="c80e52df42be9f8b2e89b467b11ab140a480cee8" />    <!-- TC5316200 -->
                <rom loadflag="load16_byte" name="045-c4.c4" offset="0x400001" size="0x200000" crc="935c62f0" sha1="0053d40085fac14096b683f4341f65e543b71dc1" />    <!-- TC5316200 -->
                <rom loadflag="load16_byte" name="045-c51.c5" offset="0x800000" size="0x100000" crc="81932894" sha1="550f15dc5892c4602422c51869f0d59f70f01e9e" />   <!-- TC538200 -->
                <rom loadflag="load16_byte" name="045-c61.c6" offset="0x800001" size="0x100000" crc="be30612e" sha1="5e8b785f917c176d6796eba0caed37b13ddb3e63" />   <!-- TC538200 -->
   </dataarea>


Goal X3 using CHA256
<dataarea name="sprites" size="0xa00000">
    <rom loadflag="load16_byte" name="209-c1.c1" offset="0x000000" size="0x400000" crc="b49d980e" sha1="722d10074f16fa7f14c71270f43fdab427b85e2b" />    <!-- mask rom TC5332205 -->
    <rom loadflag="load16_byte" name="209-c2.c2" offset="0x000001" size="0x400000" crc="5649b015" sha1="9c9674f3841e6becd3b8e63bae9b9df45ac9f11e" />    <!-- mask rom TC5332205 -->
    <rom loadflag="load16_byte" name="209-c3.c3" offset="0x800000" size="0x100000" crc="5f91bace" sha1="3864be27dce6d8f8828d3bf09bfc8116116a2b56" />    <!-- mask rom TC538200 -->
    <rom loadflag="load16_byte" name="209-c4.c4" offset="0x800001" size="0x100000" crc="1e9f76f2" sha1="b57fdc226bfe328b8848127fb4292295f1287bf6" />    <!-- mask rom TC538200 -->
</dataarea>

 

[marcao_cfh]

To be honest I don't have enough knowledge to understand those numbers lol. But then I'll go with the CHA256. Thanks!

Also, why not CHA512Y? I thought the difference between 256 and 512Y is the max C rom size they can fit.