Help dumping a SNES indie cart

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Ziggy587
Posts: 174
Joined: Fri Oct 08, 2010 6:08 pm
Location: NY, USA

Help dumping a SNES indie cart

Post by Ziggy587 »

I have purchased the SNES indie cart Sydney Hunter and The Caverns of Death. The cart works, but it's improperly using a 3.3v flash memory chip. There's a voltage regulator, but the address and data lines are only being passed through resistors. This is said to possibly be problematic for the console, and I'd rather not stress 30 year old hardware that is getting more and more expensive to replace. I would love to be able to play this game on a flash cart, and I would even write the game to a 5v memory on a custom PCB to replace the one that I bought.

I used a Retrode to dump the game to PC. The game will not load in an emulator or on a flash cart, I only get a black screen. I've also tried writing the game to an EPROM on a custom PCB, but that also only results in a black screen.

The cart PCB uses resistor networks, and depending what footprints you populate you can set the cart as LoROM or HiROM. The footprints that are populated on this PCB are for LoROM. When I load the ROM in an emulator, it gives me the following information.
Mesen wrote:File: Cavernsofdeath.12F6.sfc
Game: CAVERNSOFDEATH
Game code: SNES
Type: LoROM
Map Mode: $20
Rom Type: $00
File size: 256 KB
ROM size: 256 KB
bsnes wrote:game
sha256: 125b5ac0f6246f9b2d532d964c4a5829654f7a779d909f5cf7d89b515a79460d
label: Cavernsofdeath.12F6
name: Cavernsofdeath.12F6
title: CAVERNSOFDEATH
region: NTSC
revision: 1.0
board: LOROM
memory
type: ROM
size: 0x40000
content: Program

board: LOROM
memory
type:ROM
content:Program
map
address:00-7d,80-ff:8000-ffff
mask:0x8000
I read that the SNES internal header was used as part of the approval process, but not actually used by the system to run the game. So that's why I thought writing the game to an EPROM would work, but I still only get a blank screen. I was under the impression that emulators and flash carts rely on this header in order to know how to run the game, so I was assuming it wasn't running because of a bad header, but from the above info it looks like the emulators are reading the header correctly. So I don't know why it's not working.
lidnariq
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Joined: Sun Apr 13, 2008 11:12 am

Re: Help dumping a SNES indie cart

Post by lidnariq »

A picture of the PCB will help
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Ziggy587
Posts: 174
Joined: Fri Oct 08, 2010 6:08 pm
Location: NY, USA

Re: Help dumping a SNES indie cart

Post by Ziggy587 »

I found a pic of it already posted in this thread: viewtopic.php?p=215726#p215726

Image

edit: I can provide better pics of my own PCB if needed.
lidnariq
Posts: 11432
Joined: Sun Apr 13, 2008 11:12 am

Re: Help dumping a SNES indie cart

Post by lidnariq »

It would help to know if anything's on the other side.

When you dumped it, it only gave you 256KiB? That's a 4MiB 'PROM, and it could be checking for stuff beyond the lowest 256KiB of your dump. (Can you tell the retrode to try to dump more than just 256 KiB?)
calima
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Joined: Tue Oct 06, 2015 10:16 am

Re: Help dumping a SNES indie cart

Post by calima »

The rom is just a google search away? I mean, by all means fix your dumping process, but from a time perspective...
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Ziggy587
Posts: 174
Joined: Fri Oct 08, 2010 6:08 pm
Location: NY, USA

Re: Help dumping a SNES indie cart

Post by Ziggy587 »

Thanks for the help, guys.

Sorry, I should have mentioned, there's nothing on the back of the PCB.

Yes, the Retrode dumps the game as 4MiB. I didn't find this odd since 4MiB isn't unheard of for SNES games, especially smaller games such as this as well as homebrew games.

I believe you can tell the Retrode to dump a specific size. But I'm either not setting the config file correctly, or I'm having trouble with my Retrode. I haven't been able to write save files back to carts, so I'm not sure if there's a problem with the Retrode or not.

So when I originally purchased this game some years back, the ROM wasn't easily found online. At least, I couldn't find it. I didn't find that odd since it was a newly released indie game, and it would be in bad taste to pirate it. I haven't thought to check again for it until not. Yeah, it's easy to find now LOL. The ROM I found online, it's 16 MiB. So there's the answer.

Very strange though, when I load the internet acquired ROM into Mesen it's still identified as a 4 MiB game, although it boots and seems to work fine (at least the intro played fine). I took a look at the it in a hex editor. Admittedly, I have very limited knowledge of using a hex editor, but I think I know what the problem is. There's some very large areas of the ROM that are empty. I'm thinking this is messing up the heuristics of the Retrode and Mesen.

At any rate, I'll just use the internet acquired ROM for now. I might have to invest in a new (and still supported) cartridge dumper. The Retrode has been great, but it's no longer supported and it seems to be getting buggy for me.
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Individualised
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Re: Help dumping a SNES indie cart

Post by Individualised »

I think "isn't unheard of" is an understatement, a good portion of the SNES's library was under 4mib in fact.

Out of curiosity, have you tried both your dump and the downloaded ROM in bsnes?
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Ziggy587
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Location: NY, USA

Re: Help dumping a SNES indie cart

Post by Ziggy587 »

Yes, my dump does not load in bsnes but the downloaded ROM does.
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