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Sega ST-V Cart Conversion

twistedsymphony said:
reading was fine it wasn't wirting properly, so the verification process was correct and was indeed failing.

For me the temporary solution was to use buyicnow.com to write the chips for me, and I eventually bought a better programmer, as that was the straw that made me ditch the GX4x4 for good.
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Ah so which programmer did you end up purchasing to use?

Also for reference for anyone else, can you confirm this command prompt input for doubling the ROM size from 16 to 32? This is what I used:

Copy /b mpr20122.7 + mpr20122.7 mpr20122merged.7


All of the files I see are 4MB except for the one 2MB that I doubled in size. So after prepared, there are 8 files total, all 4MB in size. Is this correct? Making sure before I send off to buyicnow.
 
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Update: Im still waiting on the pre-programmed chips to arrive, but shipping says Friday so Im hoping to be able to try this and report back for everyone by Monday !
 
So I had a chance this week to install the chips and give it a test. Everything seems to work, with a few minor problems.

Time didn’t allow for me to sit down and really put it through the paces; but did a play though and noticed times when certain parts of the song would be missing, almost like certain “instruments” missing. Iv played Cotton boomerang thousands of times on the Saturn, but I have never owned the STV cart. So am pretty familiar with it on SS, and the music was the only thing I noticed being “off” slightly. It was almost like it happened during parts of the game when there was too much going on, lots of explosions and enemies on screen at the same time (one example was the latter half of stage 3 ). Also, the overall volume (sound and music” was extremely high, to the point where I have to turn the trim pot for volume on the STV all the way down.

Would be great if someone who has the Multi or a cotton Boomerang cart to chime in and say if this is unusual behavior or normal, as I don’t have an original to cross compare with.
 
Glad to hear it's working!

The audio issues you're experiencing are puzzling. the game code and assets are all lumped together in one memory space so it's hard to imagine audio volume or missing notes without very selective/specific corruption of the data; which is unlikely, and even less likely to be caused by the conversion process.

Then again I have a "broken" NAOMI cart that works except it plays no music, and it's essentially the exact same situation, so who knows.

I don't know the game well enough to know what it's supposed to sound like but you could check out a youtube long play or something
View: https://www.youtube.com/watch?v=vBDzbQ3iUPc
 
I updated the OP removing irrelevant information and questions that have been since answered. Also updated photos to reflect the final conversion using Kynar.

twistedsymphony said:
The audio issues you're experiencing are puzzling. the game code and assets are all lumped together in one memory space so it's hard to imagine audio volume or missing notes without very selective/specific corruption of the data; which is unlikely, and even less likely to be caused by the conversion process.
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I agree! The first thing I did was go into the Sound test on the Bios and played each BGM all the way through, and to my surprise it sounded perfect, no errors. So I played the game a bit and am able to replicate this error pretty consistently. From what I can tell, it only occurs on Stage 4 (Which probably has the most complex BGM) and seems to be directly related to too many voices being played at once. I know on Cotton 2 on the SS you have the option to add 1MB of Memory to help increase the number of voices that can play, perhaps there was some sort of hardware restraint on the STV limiting it? I also believe the audio was different on some STV VS SS games, some using Chiptune vs cd audio etc but I dont know the fine details. Maybe this is normal on the original cart too, again I have no way to test and would greatly appreciate it if someone reading this with a multi could test it out!!! Im going to try and record a play through without firing my weapon at all, then a playthough mashing the hell out of it to compare the differences.
 
Could it be related to byte/word mode of the eproms? I remember having issues in the Cyvern conversion when I was using 64mb eproms instead of 32 for sound as they did not have a pin to select byte/word mode. Seems to be pin 33 on the MX29L3211MC. Just a wild guess though.
 
nnap said:
Could it be related to byte/word mode of the eproms? I remember having issues in the Cyvern conversion when I was using 64mb eproms instead of 32 for sound as they did not have a pin to select byte/word mode. Seems to be pin 33 on the MX29L3211MC. Just a wild guess though.
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That's an important factor on a lot games as the Audio Rom is usually 8-bit and many larger ROMs nix the byte/word pin (and function) to make room for an additional address line.

that's not the case here though as there is no dedicated audio ROM, all of the ROMs are 16-bit and they all are used together to make one big memory space (like a CD or an SD card with a file structure)

I think more likely there is a hardware limit on the number of simultaneous sounds that is getting reached and it's just a quirk of the game.
 
twistedsymphony said:
That's an important factor on a lot games as the Audio Rom is usually 8-bit and many larger ROMs nix the byte/word pin (and function) to make room for an additional address line.

that's not the case here though as there is no dedicated audio ROM, all of the ROMs are 16-bit and they all are used together to make one big memory space (like a CD or an SD card with a file structure)

I think more likely there is a hardware limit on the number of simultaneous sounds that is getting reached and it's just a quirk of the game.
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I’m starting to think that conclusion is correct. Played some more last night and can recreate it on other levels when there is a lot going on. I also noticed WAY more slowdown than on the SS version, which leads me to believe that would tie into the same issue with some limiting factor in the hardware.

Im not knowledgeable enough about the hardware to know if this is even possible, but perhaps a failing component on my motherboard in the sound section could also be the culprit? Iv never recapped or replaced anything on this STV, not do I have a second Mobo anymore to test against.

I only have a few other carts which are all legit , Radiant silver gun, Souky, and Die Hard. I’ll pop some of them in and give it a run to see if I’m noticing any other odd audio issues.
 
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