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PostPosted: Thu Jul 23, 2015 11:04 pm 
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Joined: Sat Jun 03, 2006 9:17 pm
Posts: 303
Been trying to do a Yoshi Island 2 Kamek's Revenge. I know it can be done as there are a few websites that have it for sale sadly. Been banging my head trying to get this one going, just have not been able to. Does anyone know what donor is required? I tried using Stunt Race FX's as it seem's to have everything needed except for twice the sram. Anyone have any ideas? Thanks


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PostPosted: Sat Jul 25, 2015 11:14 am 
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Joined: Fri Jul 04, 2014 2:34 pm
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Location: Germany
You need Yoshi's Island as a donor as there's no other compatible board with GSU-2 chip. Only that can support games larger than 8MBit.

You could also try Doom and manually solder in a battery/save circuit, but that won't fit within the cartridge.


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PostPosted: Sat Jul 25, 2015 2:46 pm 
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Ice Man wrote:
You need Yoshi's Island as a donor as there's no other compatible board with GSU-2 chip. Only that can support games larger than 8MBit.

You could also try Doom and manually solder in a battery/save circuit, but that won't fit within the cartridge.



Would the Super Famicom version work?


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PostPosted: Sun Jul 26, 2015 8:35 pm 
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Joined: Mon Jul 02, 2012 7:46 am
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The patch appears to append an extra 0x2000 bytes at the end, making it too large for a repro. It's not that much data, so it could easily be moved to an unused section of the ROM, but unless you do so, you won't be able to build it. Beyond that, as Ice Man has said, Yoshi's Island is the only truly compatible donor, as the GSU-1 can only address up to 8Mbit ROM, and Yoshi's Island is 16Mbit. The only other two games that use the GSU-2 are Doom and Winter Gold, the former doesn't have battery-backed SRAM (I'm not sure what Winter Gold has SRAM-wise, but it's super expensive anyway). Yes, the SFC version would work fine, but as I said, you'd need to modify the ROM to fit within the 16Mbit size boundary.

Edit: The "2.0" version seems to not have the same issue, so if that's what you're using, then you can ignore that part of my comment.


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PostPosted: Tue Jul 28, 2015 2:07 pm 
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Joined: Fri Jul 04, 2014 2:34 pm
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Location: Germany
Region of cartridge doesn't matter. Just has to be a Yoshi's Island GSU-2 cartridge.

Either way, I didn't have any size problems with it. o_O
I was using a 27c160 EPROM for it.


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PostPosted: Tue Jul 28, 2015 9:25 pm 
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Awesome. Now, if I can find a 2.0 that work's lol, having issues with that.


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PostPosted: Wed Jul 29, 2015 6:33 am 
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Posts: 291
Location: Germany
2.0 (GSU) -> Yoshi's Island. There is NO other choice.


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PostPosted: Thu Aug 06, 2015 5:40 pm 
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Joined: Mon Jul 02, 2012 7:46 am
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Ice Man wrote:
2.0 (GSU) -> Yoshi's Island. There is NO other choice.


I think he means 2.0 as in the bugfixed "2.0" version of the patch (it's actually v1.96). You can find it here. Get a headerless v1.0 YI ROM (it should be exactly 2,097,152 bytes) and apply the headerless version of the patch (the second link in the OP, directly above the banner image). The end result should be a headerless ROM that is the exact same size as the original. Use that and it should work fine. I just finished building one myself. I can confirm it at least boots, but I haven't had the time to actually play through it yet. Here are checksums to help you verify your ROM:

Original YI v1.0 ROM (headerless)
CRC32: D138F224
MD5: CB472164C5A71CCD3739963390EC6A50
SHA-1: C807F2856F44FB84326FAC5B462340DCDD0471F8
SHA-256: 9B4957466798BBDB5B43A450BBB60B2591AE81D95B891430F62D53CA62E8BC7B

YIKR v1.96 (headerless)
CRC32: 47CC980B
MD5: 61B43C72BDA73C9AEA74A1C2BEB216F2
SHA-1: 0331571D449444EAF0ECF4B6B034C31BEF4ECB11
SHA-256: 01D82014883E0E2C4CB1F788232B5D41723FBC07B8A9F1A26A5883DE24E3F88E


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PostPosted: Sun Sep 04, 2016 6:39 pm 
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Joined: Tue Jul 05, 2016 2:47 pm
Posts: 3
I'm sorry for bumping this old thread, but I've run into some issues with my own YI romhack cart and this is one of the only places I've been able to find where people have been talking about making YI romhack repros.

Here's a video of what the cart does: https://www.youtube.com/watch?v=DjuRjE43tiU
As you can see the logo at the start shows up, the music plays fine, the text at the bottom appears... but all of the graphics are garbled and it eventually reboots.

Here's what I've done:
I picked up a JPN Yoshi's Island and an M27C160-100 16mbit EPROM. I cleaned the cart and tested it before desoldering the Mask ROM. I patched a valid YI ROM to SMW2+2 and verified that the file worked in higan. I then burned it to the EPROM using a GQ-4x4 programmer. It wrote and verified, and I have re-verified the chip a bunch of times. I wired a 42pin socket to the board using this diagram which should, according to my understanding, convert the chip to 8bit mode. I've used my multimeter to test all the connections at least twice now, and the socket is connected using kynar that's no longer than about 3 inches.

In my testing, I took another M27C160 EPROM and burned the stock YI ROM to it, and it does the exact same things (logo, music fine, garbled graphics, reboots). So it's likely not a problem in the romhack, but something I've done wrong. I'm really confused about why the music plays just fine and the text shows up, but all the other graphics are junk. Other carts play fine in my SNES, so the connector there is clean, and I've cleaned the pins on this cart a few times in testing, just to make sure I didn't re-dirty them while working on it.

Does anyone have any ideas of what I should test?


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PostPosted: Thu Sep 08, 2016 7:04 pm 
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Joined: Sun Dec 02, 2012 8:17 am
Posts: 481
Location: East Texas
Try replacing your SRAM chip.


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PostPosted: Fri Sep 09, 2016 1:51 pm 
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Joined: Tue Jul 05, 2016 2:47 pm
Posts: 3
Markfrizb wrote:
Try replacing your SRAM chip.

I've actually moved the socket from one cart to a second one in the time since posting that. I thought I might have done something bad to the first one (ie: lifted a trace just enough to break it without being visibly broken). The second cart does the same thing with both of the programmed EPROMs. Same exact stuff just like in the video. Both carts, both EPROMs. Oh, and both carts definitely worked before I started meddling with them.

Given that I'm running out of ideas, I bought some more M27C160 chips. I kinda doubt it's the chips, since they verify over and over again as valid, but I figured what the hell, it's just another $10.

I feel certain that there's some part of the process that I've done wrong, but I just can't figure out what it is. Thank you for the reply, and actually, if you are who I think you are, I emailed you looking to buy some boards just a couple weeks back. I've got your site bookmarked as a backup plan, in case I never figure out what I've done wrong here.


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PostPosted: Mon Sep 19, 2016 7:54 am 
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Joined: Tue Jul 05, 2016 2:47 pm
Posts: 3
Just to close the loop on this, Markfrizb (who runs http://retrocircuits.com/ ) helped me over PM with some suggestions as to what I could try to figure out the root problem. It ended up actually being the cheap kynar I was using, it was either causing noise or poor conduction on some of the address lines.

All I had to do was remove my socket and rewire it with some shorter lengths of better wire and everything worked. It would have worked first try if I had just used better wires to start with. :(

Thanks again for all your help, Markfrizb.


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