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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.
 
Just wanted to follow up on this topic.

I dont think the audio glitch I mentioned before was due to a failing component on my motherboard, perhaps its completely normal.

On another note, I was able to do a successful conversion from Shanghai to Shienryu!

I was concerned that the "boot ROM" EEPROM that is in the orignal cart would prevent it from loading when it was not present; but that wasn't the case. This is the line of code in reference to the EEPROM that some games use.

ROM_LOAD( "eeprom-shienryu.bin", 0x0000, 0x0080, CRC(98db6925) SHA1(e78545e8f62d19f8e00197c62ff0e56f6c85e355) )
ROM_END

I switched the resistor jumpers to the correct configuration mentioned before in my post and soldered in the MX29L3211MC in IC2,IC3, IC7 and that was it! So im wondering if other conversions would be possible without that EEPROM as well, or if this was just a fluke. I know all the conversions Iv seen of Souky or RSG DO use the boot EEPROM.
 
twistedsymphony said:
I have a handful of STV Games and I recently cracked them open just to see what these looked like. I have 4 carts and to my surprise all 4 had unique PCBs. two of them used a flash ROM in addition to the Mask ROMs and one of them had a Protection chip. some carts I've seen have a socketed ROM in lieu of a flash chip. So there's a lot of variation here.

I think for starters you'll probably want to use an unprotected cart as your donor (maybe the protected carts can have their protection disabled?) and any protected game you'll probably want to use a cracked copy (such as those used in the multi kits).

In general though your first stop should be the MAME driver: https://github.com/mamedev/mame/blob/master/src/mame/sega/stv.cpp

at first glance it seems all games use the same basic memory map which is good it means there's no logic to contend with.

looking at some ROM definitions
Code: 
ROM_START( colmns97 )
    STV_BIOS

    ROM_REGION32_BE( 0x3000000, "cart", ROMREGION_ERASE00 ) /* SH2 code */
    ROM_LOAD16_BYTE( "fpr19553.13",    0x000001, 0x100000, CRC(d4fb6a5e) SHA1(bd3cfb4f451b6c9612e42af5ddcbffa14f057329) )
    ROM_RELOAD_PLAIN ( 0x0200000, 0x0100000 )
    ROM_RELOAD_PLAIN ( 0x0300000, 0x0100000 )
    ROM_LOAD16_WORD_SWAP( "mpr19554.2",     0x400000, 0x400000, CRC(5a3ebcac) SHA1(46e3d1cf515a7ff8a8f97e5050b29dbbeb5060c0) ) // good
    ROM_LOAD16_WORD_SWAP( "mpr19555.3",     0x800000, 0x400000, CRC(74f6e6b8) SHA1(8080860550eb770e04447e344fb337748a249761) ) // good
ROM_END

ROM_START( cotton2 )
    STV_BIOS

    ROM_REGION32_BE( 0x3000000, "cart", ROMREGION_ERASE00 ) /* SH2 code */
    ROM_LOAD16_WORD_SWAP( "mpr20122.7",    0x0200000, 0x0200000, CRC(d616f78a) SHA1(8039dcdfdafb8327a19a1da46a67c0b3f7eee53a) ) // good
    ROM_LOAD16_WORD_SWAP( "mpr20117.2",    0x0400000, 0x0400000, CRC(893656ea) SHA1(11e3160083ba018fbd588f07061a4e55c1efbebb) ) // good
    ROM_LOAD16_WORD_SWAP( "mpr20118.3",    0x0800000, 0x0400000, CRC(1b6a1d4c) SHA1(6b234d6b2d24df7f6d400a56698c0af2f78ce0e7) ) // good
    ROM_LOAD16_WORD_SWAP( "mpr20119.4",    0x0c00000, 0x0400000, CRC(5a76e72b) SHA1(0a058627ddf78a0bcdaba328a58712419f24e33b) ) // good
    ROM_LOAD16_WORD_SWAP( "mpr20120.5",    0x1000000, 0x0400000, CRC(7113dd7b) SHA1(f86add67c4e1349a9b9ebcd0145a30b1667df811) ) // good
    ROM_LOAD16_WORD_SWAP( "mpr20121.6",    0x1400000, 0x0400000, CRC(8c8fd521) SHA1(c715681330b5ed37a8506ac58ee2143baa721206) ) // good
    ROM_LOAD16_WORD_SWAP( "mpr20116.1",    0x1800000, 0x0400000, CRC(d30b0175) SHA1(2da5c3c02d68b8324948a8cdc93946d97fccdd8f) ) // good
    ROM_LOAD16_WORD_SWAP( "mpr20123.8",    0x1c00000, 0x0400000, CRC(35f1b89f) SHA1(1d6007c380f817def734fc3030d4fe56df4a15be) ) // good
ROM_END

ROM_START( astrass )
    STV_BIOS

    ROM_REGION32_BE( 0x3000000, "cart", ROMREGION_ERASE00 ) /* SH2 code */
    ROM_LOAD16_BYTE( "epr20825.13",                0x0000001, 0x0100000, CRC(94a9ad8f) SHA1(861311c14cfa9f560752aa5b023c147a539cf135) )
    ROM_RELOAD_PLAIN ( 0x0200000, 0x0100000 )
    ROM_RELOAD_PLAIN ( 0x0300000, 0x0100000 )
    ROM_LOAD16_WORD_SWAP( "mpr20827.2",     0x0400000, 0x0400000, CRC(65cabbb3) SHA1(5e7cb090101dc42207a4084465e419f4311b6baf) ) // good (was .12)
    ROM_LOAD16_WORD_SWAP( "mpr20828.3",     0x0800000, 0x0400000, CRC(3934d44a) SHA1(969406b8bfac43b30f4d732702ca8cffeeefffb9) ) // good (was .13)
    ROM_LOAD16_WORD_SWAP( "mpr20829.4",     0x0c00000, 0x0400000, CRC(814308c3) SHA1(45c3f551690224c95acd156ae8f8397667927a04) ) // good (was .14)
    ROM_LOAD16_WORD_SWAP( "mpr20830.5",     0x1000000, 0x0400000, CRC(ff97fd19) SHA1(f37bcdce5f3f522527a44d59f1b8184ef290f829) ) // good (was .15)
    ROM_LOAD16_WORD_SWAP( "mpr20831.6",     0x1400000, 0x0400000, CRC(4408e6fb) SHA1(d4228cad8a1128e9426dac9ac62e9513a7a0117b) ) // good (was .16)
    ROM_LOAD16_WORD_SWAP( "mpr20826.1",     0x1800000, 0x0400000, CRC(bdc4b941) SHA1(c5e8b1b186324c2ccab617915f7bdbfe6897ca9f) ) // good (was .17)
    ROM_LOAD16_WORD_SWAP( "mpr20832.8",     0x1c00000, 0x0400000, CRC(af1b0985) SHA1(d7a0e4e0a8b0556915f924bdde8c3d14e5b3423e) ) // good (was .18s)
    ROM_LOAD16_WORD_SWAP( "mpr20833.9",     0x2000000, 0x0400000, CRC(cb6af231) SHA1(4a2e5d7c2fd6179c19cdefa84a03f9a34fbb9e70) ) // good (was .19s)

    // 610-0374-90   1998     317-5040-COM   ST-V      (yes, the 317-5040-COM chip was reused for 3 different games and on both Naomi and ST-V!)
    ROM_PARAMETER( ":315_5881:key", "052e2901" )
ROM_END

So I don't know what any of these carts look like but if we look at Columns 97 we see fpr19553.13 is the first thing loaded, this is 800Mbit so it's either a 27c080 or a flash ROM. then we have some gap space followed by a series of 32Mbit ROMs which would be your Mask ROMs.

If we look at cotton2 we'll see that there is no leading flash or socketed ROM it just the MASK ROMs. Then we can look at astrass and see that in addition to the leading ROM and the Mask ROMs there's also security key indicating that it's a protected game. There's also a note here that the same chip is used on multiple games, so maybe a conversion is possible with protection in place among those games?

--------------
Next thing to do would be to test a conversion virtually in MAME by simply renaming all of the ROM files for a target game, to that of your donor cart's game and then see if MAME will run it. If so then there's a good chance that the conversion will work in the real world.

We'll also probably want to document which games use which carts so we know what are suitable donors and what are not.
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I'm really curious which Carts use Flash Roms along with Mask Roms?

I looked at the spreadsheet I couldn't tell which

Reason why I'm asking is because I've read a lot about bit-rot and I've heard that flash memory is quite volatile

I really love these games and would like to have them working years to come
Unlike many collectors I love popping my original games in and playing on original hardware :D

Following games I'd really like to know if they use Flash Roms
Radiant Silvergun
Soukyugurentai
Shienryu
Astra Superstars
Groove On Fight
Golden Axe The Duel
Suikoenbu

Also you mentioned that the ST-V carts seem to be the predecessor to the NAOMI carts
Do you know if the NAOMI carts used Flash or Mask roms?

I know a lot of this isn't really relevant to the discussion but its the best place to ask :P
 
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