Tetris Plus 2 Conversion
- Thread starter FPJ
- Start date
FPJ
Student
I found a junk Rev X board with lots of 27c040 100ns chips on it and replaced 26-29. Still doesn't work entirely, but progress! I now get this garbled screen followed by static. Power is fine an upping it some didn't help.
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does it get past that screen? if so it seems to imply that at least the program ROMs are correct now... probably has some issues with the txt ROMs which I think are 10 and 11
Hammy
Enlightened
yes, that's it! ... so do you think BBB only works with this stuff removed?
I found a pic of the BBB with mobo and see what you mean, it's missing some chips in that section
hmm all of my MS32 stuff is in storage but I don't think any of my boards are missing those chips. I distinctively remember comparing mobos side by side trying to work out what was different to make one work and the other not, and aside from a few small capacitors bridged across pins on a couple of chips I didn't see anything, I certainly don't recall any missing chips.
FPJ
Student
Yeah. It goes past that to this screen. It almost looks like something is going on underneath the static. I'll check out redoing 10 and 11 a little later today.
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AlxUnderBase
Enlightened
made this mistake and i confirm any JMS32 cartridge will work only if you insert in the correct orientationUnfortunately, jumpers did not fix it.
Did you know that the connectors on the ROM board don't stop you from putting it on upside-down? And also that even though when the game is in the case, you orient the text with the bottom facing away from the JAMMA edge, if you don't have the case on because you're trying to get a conversion to work, the text printed on the board should be oriented the other way with the bottom facing toward the JAMMA edge? This knowledge did not fix the problem either, but it was certainly a good thing to figure out.
I tried putting the Game Tengoku ROMs back on just to make sure there wasn't an issue with the ROM board and everything booted up just fine. There must be something else I'm missing. Assuming this particular conversion works at all, I suppose.
That to me looks like what you get when you're using the wrong data encryption for the security chip.
the "security" is just encrypted graphics, so the game plays but you get garbage like this when it's wrong.
that is to say, I'm sure your security chip is the right one, so I would focus on the ROMs that are encrypted which are ROM 10 and ROM 30
FPJ
Student
So do I need decrypted ROMs? Or do I just need to try redoing those?
FPJ
Student
Yeah, they verify and are in the right spots.
maybe try a faster speed on the .30 ROM?
FPJ
Student
I actually did that earlier. Lol. It's on 100ns too. I can credit it and hear sound. So it's playing blind at least.
Hammy
Enlightened
Did you dump your original roms? they may be another version that used another chip?...
FPJ
Student
For the Game Tengoku ROMs? I haven't, but I could. The security chip has the number printed on it, so unless that's wrong it's the right one as far I can tell.