SNES Reproduction Cart Tutorial

With a bit of know-how and some basic programming gear, you can make your own SNES reproduction carts from your old unwanted games. This short tutorial will aim to show you how it’s done, I have drawn information from a number of sources and I’ll supply a bunch of links for further reading.

Note that the cartridges I have for sale in my Shop page have not necessarily been modified in this manner, the methods I use for those carts vary from game to game and are more advanced utilising different types of chips. If you are looking for a quality reproduction of a game then feel free to request it from me.

Introduction

The method I am using here utilises the M27c801 Eprom, an 8Mb package very similar in structure to the original Nintendo Mask ROM packages that are found in game cartridges. This method can necessitate the use of multiple chips if your ROM is greater than 8Mb in size, but I still think it’s easier for beginners than trying to use a bigger flash chip which requires very tricky soldering and a bit more know-how. Now, there may be better ways of doing certain steps that I outline below, but I will just be teaching you a method that I know works as I have done it myself many times – if you have more questions then please ask and I’ll do my best to clear anything up for you.

Comparison of M27c801 Eprom and original SNES Mask ROM pinouts


Parts

Description Quant Part
Eproms See §2 M27c801
Multiplexer See §2 74HCT139
Eprom Programmer TL866 (Suggestion)
Gamebit screwdriver 3.8mm
Desoldering pump

A quick word on the Eproms you’ll be using – they are, in fact, discontinued chips. This means that you won’t be able to buy them new (easily), so you’ll need to find them second hand – this is why I gave you a link to eBay. Hopefully any chips you buy will come completely blank, but if you get some that still have some data on them you will have to wipe them with a UV Eprom eraser. These aren’t too pricey, thankfully, but just beware.


1 – Pick your ROM

This is obviously completely up to you, I won’t go into detail on how to acquire the ROMs themselves but just be sure that whatever ROM you have is functional. You can test it in an emulator first to be sure that it boots up normally.

I have included some pictures from the making of my Super Back to the Future 2 repro for illustrative purposes.

2 – How many Eproms do you need?

The M27c801 is rather small at only 8Mb, and while this is enough for some ROMs there are some that stretch all the way up to 32 or even 64Mb in size. If you plan on burning a ROM > 8Mb in size you will need a number of chips equal to ROM size divided by 8 (and then rounded up if necessary) – so a 20Mb game would need 3 chips total. Whenever you need more than one you will also need to control the information with a multiplexing IC, so get one of the 74HCT139 chips I put in the parts list if this is the case for you. See the section on “Chip Stacking” for more information on this as it is otherwise beyond the scope of this tutorial.

Please note that you should apply any translation patches you require onto your ROM before buying your Eproms, as they often increase the size of the ROM somewhat. For example, FFV grows from 16Mb to 20Mb once all the speech has been translated into English from Japanese and you would be annoyed if you had only purchased two Eproms!

3 – Picking a donor cart

This one's on its way to the great SNES in the sky

This one’s on its way to the great SNES in the sky

The next hurdle facing you will be the selection of a “donor” cartridge. This is the game that you will be sacrificing to make way for your new ROM. If you are seeking a translated version of a game you own, then no worries – your donor cart is simply that actual game and will be perfectly compatible. If you plan on replacing a game with a different one, then you will need to find one that has similar properties as not all SNES games were created equal…

Head over to this excellent website for a complete list of all SNES games and their header properties. You are looking for your donor cart to match your new ROM in the following fields:

  • SRAM size
  • Bank (HiROM/LoROM)
  • Chips (enhancement chips that the ROM will need for operation)

The size of the ROM isn’t a concern, nor is the ROM speed as the M27c801 chip runs faster even than the FastROM variety. Once you’ve got a match you can get started on preparing your ROM for its new home. For my Super Back to the Future 2 project I used a copy of Wedding Peach for the Super Famicom – a perfect match for that ROM.

If you find multiple entries in the list for your ROM and don’t understand the terminology in the squared brackets then have a read of this.

My donor cart and ROM match exactly

My donor cart and ROM match exactly

Follow this flowchart to guide you through the process

4 – Prepare the ROM itself

Here’s a quick list of all the software packages you potentially need for preparing your ROM:

OK, this can get a bit hairy, so I created a simple flowchart to help you through the process (see right). I’ll also go into more detail in each step.

4a – Apply any necessary translation patch

If you are translation-patching a fresh ROM then you’ll want to do it before anything else. Open up Lunar IPS and select your IPS patch file and your ROM, the program does the rest. Very straightforward.

4b – Lunar Expand

If your ROM’s size is now not cleanly divisible by 8Mb, you must first expand it to the nearest larger multiple of 8 using Lunar Expand (so a 20Mb ROM will be expanded to 24Mb, for example). It’s extremely simple, just open up the program, select the target size and click “Apply to ROM”, then navigate to your file and that should do it.

4c – uCon64 and Checksums

This programme operates on a command-line interface, but don’t be scared if you’re not experienced with this stuff – it’s easy.

  • Navigate to your uCon64 folder
  • Shift+Right-Click in that folder and select “Open command window here”
  • Enter the following: “ucon64 [filename]” (without the quotes) where [filename] is the full path of your ROM. You can easily capture this with a Shift+Right-Click on the file and selecting “Copy as path”, then Right-Clicking in the command window and choosing “Paste”.
  • You should get something that looks like this:

ucon64 out

What you’re looking for here is the integrity of the checksums. Hopefully they should both say “Ok”, but you may find (particularly if you needed to expand your ROM) that they are “Bad” – in which case you should probably fix them.

Ips and SumIf your checksums are bad:

  • Open up IpsAndSum and open your ROM.
  • Choose “Repair SNES Checksum”, the program will inform you that the checksums don’t match and ask for confirmation, click Yes.
  • Remember to save the ROM (from the File menu) after doing this otherwise no changes will be made.
  • Reload your ROM in uCon64 to confirm that the checksums are now “Ok”!

Please note that I have found that it’s impossible to fix the checksums on some translated ROMs (Final Fantasy V is one example), at least with this utility, but it doesn’t seem to affect the performance of the finished reproduction cart so if you find this is the case then I suggest ignoring it.

4d – SNES ROM Utility

Now, one thing that you must be sure of before burning your ROM onto one of your precious Eproms is that it has no copier header information, I won’t bother to explain why but trust me that it’s just something that needs doing. You might find that your ROM already has no copier header (particularly if it’s in .sfc format), but it’s prudent to check. Another modification you want to perform on your ROM is known as swap-binning. This process basically re-jigs the information inside the ROM so that it more closely mimics the way that the real SNES Mask ROMs work. You can still make non-swap-binned ROMs work, but it will require more hardware modification when you come to the installation. Lastly, you will need to break your ROM up into 8Mb chunks to allow you to burn it onto your Eproms (obviously if your ROM is 8Mb in size you don’t need to do this!).

snes rom utilLuckily, the SNES ROM Utility takes care of everything for you: the copier header, ROM splitting and swap-binning! So fire it up and open your ROM. Simply choose the Swap Bin option (the drop down menu should show 27c801 – your chip) and hit OK. You find a .bin file (or multiple, if it needed splitting – see the section on stacking chips) with the same name as your ROM in the same directory, that’s what you’ll be programming onto your Eprom.

Now, some ROMs will not load in the Utility (BS Golf Daisuki! O.B. Club is one example I have found), so you may need to remove the copier header some other way. My recommendation is to open up your StripSNES directory in a command window (using the same method as for uCon64, if you like) and enter “stripsnes [filename]” without the quotes to remove the header automatically. If your ROM requires splitting then you can do this in uCon64 by using the option: “ucon64 -s [filename]” or by downloading some other file splitting programme, but I’ve never tried this so I can’t offer any more advice than that. As I said, not swap-binning the ROM will require a bit of extra wiring, see §6.

5 – Burn your ROM

It's well worth investing in a small universal programmer

It’s well worth investing in a small universal programmer

Using whatever hardware and software package you have for your M27c801 chips, burn your ROM (or its individual chunks, if applicable). I won’t go into to much detail explaining this here, as that’s a completely different tutorial, but if you’re looking for a budget programmer then I can recommend the TL866 universal programmer that can be found on eBay from China for a very reasonable price. It is capable of programming myriad other types of chips so it could prove very useful if you’re just getting starting in this hobby.

6 – Swapping the ROMs

Right, time to get our hands dirty! Using your gamebit driver, get the cart open and take a look at the guts of your unwanted game.

Pin numbering

Pin numbering

You can immediately get started with desoldering the existing Mask ROM, I use a desoldering pump as I find that it’s the fastest and least stressful way of doing it. It usually helps if you add a bit of new solder to each joint on the back of the board that you want to remove as this allows the old stuff to flow a bit better.

Before placing your new Eprom in place, you will need to bend up some of its legs that need swapping for the ROM to operate. Please consult the table below to see which pins you need to swap, then lift those legs on your Eprom so you don’t accidentally solder them directly onto the cartridge board. Once they’re out of the way you can snip the thin sections of those legs off with a pair of snips as this makes them easier to solder onto.

Swap-binned ROM
M27c801 Cart
24 31
31 24
Non swap-binned ROM
M27c801 Cart
1 30
2 24
24 31
30 1
31 2

Solder all the other legs of your Eprom into the cartridge PCB, then solder wires onto each of the legs that you need to swap and connect them to their target pins on the PCB. You can go either through the hole on the front (just like the legs do), or wrap the wires around to the back – it’s up to you. It will probably depend on how thick your wires are etc, just make sure that the PCB will fit back in the cartridge once you’re done. Here’s my effort with my Super Back to the Future repro:

For illustrative purposes, here is my reproduction of BS Golf Daisuki: O.B. Club! – a ROM which cannot be swap-binned – note the extra pin swaps required:

Notice that I used AWG30 wire (Kynar) for this repro, this is definitely my recommendation for this kind of work as this wire is very easy to work with and doesn’t put any stress on the delicate pins of your chips if you need to bend it around.

Here's my repro of BS Golf Daisuki: O.B. Club! up and running. My donor was a NTSC-J copy of Yuu Yuu Hakusho

Here’s my repro of BS Golf Daisuki: O.B. Club! up and running. My donor was an NTSC-J copy of Yuu Yuu Hakusho

7 – Reassemble and Test

All that’s really left to do is put the cartridge back together and test it in your SNES. Before that though, just make sure that there aren’t any scraps of solder on the back of the board that may short out a connection. Desoldering can sometimes be a messy business and you might need to sweep up after yourself with your iron.


Stacking multiple Eproms

As promised, here’s a quick guide on stacking Eproms if your game is > 8Mb in size and you still want to use M27c801 chips.  I’ll preface by saying that this method only works with swap binned ROMs, if you want to do this with an un-swapped ROM then you’re on your own.

First, get yourself one of those HCT139 multiplexers I put in the parts list and enough M27c801 chips to hold your ROM. After running your ROM through the SNES ROM Utility you will find that you have multiple .bin files each of size 8Mb (or 1MB, if you prefer). Burn each of those files onto a single chip, being careful to label each one as you go (01, 02…) so they don’t get mixed up.

Next, have a look to see if your cart has a chip labelled “MAD-1” inside of it. If this chip is present then you will be connecting its pin 4 to the HCT139, but if it’s absent then you will be connecting the HCT139 to pin 49 of the cart connector (the cart connector being the contacts at the bottom of the PCB that plug into the SNES).

You will need to lift pin 24 of all your Eproms (just like for the single-chip version) and make sure to lift pin 31 of the Eprom that you solder into the PCB itself, this allows you to swap pin 31 on all your Eproms to the same pin 24 on the cart. All the other pins (except 24, see the diagram) will simply be wired to their respective locations on the cart as in the single-chip tutorial – basically all the Eproms will be in parallel with each other on the cart PCB. This method allows you to use up to 4 Eproms simultaneously, if you are using only 2 or 3 then simply leave them out from the diagram below, it remains otherwise unchanged.

How to wire multiple M27c801 chips with a 74HCT139

Refer to the SNES Mask ROM pin-out diagram in the introduction for the locations of A20 and A21 on the cart. You can access pin 49 of the cart connector through pin 31 on the cart – doing it this way makes it look exactly like the pin 24/31 swap in the single-chip tutorial, just with the HCT139 acting as an intermediary.

The +5V and GND signals can be found in many places, I took them from the relevant cart connector pins for my FFV repro (pinout can be found here). Otherwise, feel free to find your own points on the board that carry them, there are likely to be quite a few options.

Here’s my reproduction of FFV, in which I installed the English translation version into an original Japanese cartridge of the same game. Note that this cartridge doesn’t have a MAD-1 chip, so pin 1 of the HCT139 is soldered to pin 31 of the ROM socket.


That’s it! Hopefully you found some useful information in here and it will inspire you to make your own reproduction carts in the future.

References

  • The Brewery sub-forum over at NintendoAge.com is a fantastic resource for all kinds of SNES mods and hacks.
  • MrPete1985 (over on Nintendo Age) gave me some great tips and explanations, plus his own guide on SNES repro carts helped me tremendously.

–Jaska–

This entry was posted in Uncategorised and tagged , , , , . Bookmark the permalink.

38 Responses to SNES Reproduction Cart Tutorial

  1. wariznake says:

    Hey buddy. Great guide, but I’m having a problem right now. Where the hell is the Pin 49?? I read your explanation in the guide but I dont understand. Sorry to be that dumb. Hope you can help me.

    Regards.

    • Jack says:

      Sorry for the slow reply! Not a stupid question at all, it can be confusing. Pin 49 refers to Pin 49 of the cart connector (as in the pins that actually make contact to the SNES). On carts that have no MAD-1 chip (at least the ones that I’ve seen) this pin is connected to pin 31 of the old Mask ROM, use a multimeter to confirm that’s the case on your cart.

  2. bundesdrucker says:

    Hey, first of all: Thanks for the great tutorial, its been really helpful so far!
    But I’ve got a question regarding the stacking:
    1. In what order should I stack multiple EPROMs? For example, I’ve got 3 split ROMs on 3 EPROMs labeld EP-1, EP2, EP-3. Should EP-1 be the one which I solder directly onto the PCB or does it matter at all?
    2. Regarding the 31/24 swapping: I understand that you lift every 24 leg on every EPROM and connect them to the 139. And you lift the 31 leg on the very bottom EPROM. But I dont see where anything connects to the 31 pin on the PCB anymore or where the 31 leg of the second EPROM should connect to, if the one below it is lifted. Is the swap taken care of with the connection to the A20/ A21/ MAD-1 or am I missing something? I hope you understand what Im trying to say here.
    Thanks in advance 🙂

  3. Jack says:

    Sorry for the slow reply!

    1. Yes, I would personally solder EP-1 to the PCB. But to be honest it actually doesn’t matter, the important thing is to wire each chip to the HCT in the correct order.

    2. You will be connecting the HCT to pin 31 of the PCB – which I noted can be accessed through cart connector pin 49 if it’s easier. All the Chip leg 31’s (if that makes sense!) go to pin 24 of the PCB together.

  4. zolch says:

    hi,

    great tutorial! I still have one question. When I want to burn a hack, like: http://www.smwcentral.net/?p=section&a=details&id=13008 How can I see which sram, bankd and chips this will need? Is ucon64 the right program to find a donor card?

    • Jack says:

      Hi, yes uCon64 will give you everything you need to know:

      If “HiROM” is yes, then it’s a HiROM – otherwise it’s a LoROM.

      If SRAM is required, the amount is listed under “SRAM”.

      If any chips and enhancements are required, they are listed under “ROM type”.

      Hope that helps!

      • zolchulian says:

        Thanks for the reply! Can I use an USA-Rom burned to the Eprom in a PAL cartridge? Because the super mario world hacks can mainly only be applied to the us-version of the rom.

        • Jack says:

          As far as I am aware, there is no difference between the PAL and NTSC boards for the same game, EXCEPT for the region lockout. If you want to play a repro in a cart that is not designed for the same region as your console (so eg. a PAL cart on an NTSC console) it will not work without modification to the SNES (SuperCIC or region mod) or the game cart itself (swapping the region lockout chip for one from your region).

          But basically, in your case if you want to play an NTSC rom installed in a PAL cart on a PAL console, I think you will be fine without extra mods.

          Let me know how you get on!

  5. zolch says:

    hey,
    encounter the first problem. Wanted to make a reprocard of super mario omega, but my ips-patched rom is 4 mbyte, so I can´t “expand” it to 8 mbit. I´ve read that for super mario return to dinosaur land there is a xdelta patch which cut the rom back to 8 mbit. Do you know anything about this?

    • Jack says:

      Why can’t you expand it? I would normally apply any IPS patch first, then expand, so I don’t see the problem. I don’t know much about specific hacks as I haven’t any experience with them, but my advise is to try to expand you 4Mbit ROM using Lunar Expand, then testing the expanded ROM in an emulator (like BSNES, as it most accurately emulates the hardware), if it works then try burning it 🙂

      Let me know if I’ve understood you correctly.

      • zolch says:

        It´s for 4 mbyte = 32 mbit. So I would need for eproms with 8 mbit, which I want to avoid for my first reprocard.

        • Jack says:

          Ah sorry, I misread your question initially. Well I don’t know anything about that particular ROM, but if it’s 32Mbit in size then you’ll need 4 ROMs, I’m afraid (if you want to stick with the M27c801). Unless you want to use a larger 32MBit TSOP ROM chip, you can buy them with adapters to match the SNES cartridge pins, but that’s a separate tutorial – check my links at the end of this page for some help.

  6. bundesdrucker says:

    Hey after receiving my EPROMS I’ve struck a dead end. So at first I wanted to build a MM7 repro but did a pretty shitty soldering job because of no planning beforehand. Once I tried the cartridge in my SNES it seemed to boot up fine but several sprites were missing, including Megaman. Backgrounds, Sounds and Music strangely was there. Anyway, I blamed the poor soldering.
    Next I wanted to try something easier, an 8MBit game: Lost Vikings 2. I checked the checksum with ucon – ok, it was bad. So I fixed it with IpsAndSum and loaded it again in ucon64 – still bad! Trying again to fix it with IpsAndSum was not possible because it told me the checksum is fine. So I used ucon itself to fix the checksum. Trying to load this patched version into SNES utility didnt work and, because Im stupid I guess, I tried to open the unfixed ROM and it worked. Swap-bin’ed the ROM and burned it. Didn’t work, no wonder I guess.
    So lastly I tried Super Probotector: Alien Rebels (PAL Version of Contra III). Checksum was fine, loaded up nicely in the SNES-Utility and burned it again. But, again, I got the black screen.
    So basically I understand why the first two tries might have gone wrong but I have no idea why the third one didnt work. Soldering checks out, wiring as well. The programming of the EPROM and the check afterwards seemed succesful so Im all out of ideas. I first thought the chips were deffective but would programming them even start then? Or might my programmer be broken?

    • Jack says:

      Hi, sorry to hear you’re having trouble. It’s tricky to say what may be the issue with your Super Probotector repro, but here’s a few things to check:

      – Make sure that your M27c801 chips are completely blank before burning to them, if they are not blank then you will need to erase them with a UV eraser (or leave them out in the sun for a while).

      – You can check if the chips or programmer are defective by reading the data back off them and comparing the hex files with a hex editor to see if there were any errors.

      – It is critical that the donor cart you are using is suitable for the ROM you are burning. For the Probotector ROM, you need a cart that has:
      -LoROM bank
      -0kB SRAM
      -No expansion chips
      -Original ROM size of 8Mb (not sure how critical this one is, actually, but best to stick to it…)
      -If your SNES doesn’t have a region mod, then the cart must also be a PAL one.

      – Of course, I have to say: check it again with your multimeter. Ensure that all the connections are in the right place. Did you swap the two pins correctly?

      Let me know how you get along 🙂

  7. Tom says:

    I got a question:
    I got a GQ-4x Programmer and TSOP from ST: M29F032
    Boards: TSOP ADapter 3 from buyicnow, closed resistors.
    The adapter is not recognized until I saw that i need a tsop40 to 36 converter as seen on mmmonkey.
    I then bought an adapterboard to be able to program them:
    DIP40-DIP36 Programmer Adapter I-1
    Item ID00002570

    and also a nonassembled version:

    DIP40-DIP36 Programmer Adapter II
    Item ID00002623

    None of my so far 3 soldered M29s are detected by the programmer.
    Questions:
    A) do i have to close a jumper on the first adapter ?
    B) is my 2nd adapter assembled correctly ?

    Pics here:
    Adapter I-1
    http://i.imgur.com/wtnmHnk.jpg
    http://i.imgur.com/i9k2309.jpg

    Adapter 2
    http://i.imgur.com/Ags2Q3p.jpg
    http://i.imgur.com/zD9R92b.jpg

    • Jack says:

      Hi Tom,

      Unfortunately I have no experience with that programmer, so I can’t offer much help I’m afradi 🙁

      What I do know is that the hardware you need for the TL866 programmer is as follows:

      TSOP40 – DIP36 Adapter Type III (the same one you have)
      An adapter to convert that into a format recognisable by the TL866

      With this hardware, you must then set the chip ID to the 29f033 as the 29f032 isn’t supported (you will need also to disable the ID check to allow programming to proceed).

      Sorry I couldn’t offer some more specific help for your problem, but maybe this explanation has some overlap with your issue.

      Thanks
      Jack

      • Tom says:

        i’m waiting for another adapter, official one,…hoping I get results from this. Thx for the reply!

      • Tom says:

        just reporting back: i got the real adapters now, not that cheap with about 40$+shipping to Europe. Chips are detected and i’ve burned them, put them on the adapter but the game isn’t working. I did sth wrong, but I don’t know what. I guess it’s because i took an already patched secret of mana 2 (Seiken densetsu 3 + eng 1.01 translation) and did a “copy /b” to create a binary file. I guess the right step was to take the patch, Lunar IPS patch the real japanese rom, then “copy /b” the translated rom to create a binary which must be copied to the tsop….so much money wasted already..next time I just stack 4 M27s…

  8. Chris says:

    Jack thank you so much for the tutorial.

    What would you say is currently the cheapest alternative for an EEPROM programmer and UV eraser? has anything changed since the writing of the article? I see many versions of programmers on EBAY, and since I’m quite ignorant on the subject, I don’t really know what to buy.

    For example, there are some very compact USB pendrive-like EEPROM programmers, for less than USD$10, but I gather they are missing slots for the pins used by the EEPROM used on SNES carts.

    From what I can gather, the UV eraser is mandatory, since most likely the (second hand) EEPROMS may have data in them already.

    And EEPROMs are around USD$2 (ish) each, right?

    Any input would be aprecciated.

    Thank you

  9. Robin says:

    Hope someone can help. I’ve used your method for making repos and has worked great for me but I have a problem now. I made a Harvest Moon repo and it works great but it doesn’t seem to want to save for some reason. I replaced the battery but that didn’t do the trick. My question is for mad-1 do you remove pin 4 from PCB and connect it to pin 1 of 139 or just solder pin1 from 139 to pin 4 of mad-1 straight in the hole. Thanks

    • Jack says:

      You don’t need to lift pin 1 of the MAD-1, you are simply tapping into the /OE signal on the cart PCB. You can also get this signal from the ROM (see the ROM pinout diagram) – are you certain it’s a MAD-1 chip on your cart? There are some variations (MAD-R and MAD-2, I believe) that have different pinouts, so maybe try to get the /OE signal from somewhere else. Other than that I can only suggest that you check your wiring, and that the donor cart you’re using is the correct configuration for the ROM you’re trying to play on it.

  10. Andy Herman says:

    Hey Jack, I followed your tutorial and got my Dragonball Z game to work using the M27c801’s.

    So my main questions are how come these eprom’s need to be wired anyway? How come they don’t just work like the original ones?

    As for a game that is 2Mb, how come you recommend stacking two 1Mb’s instead of getting a larger eprom? Is it not the same process using a larger eprom say M27c160?

    Thanks,

    • Jack says:

      Nice work 🙂

      The reason the eeproms need rewiring is that the original SNES mask roms don’t match the pin out of the M27c801 exactly. The swap bin process changes the structure of the rom to get the output almost exactly the same, but still those two pins need swapping. I can only assume that the reason Nintendo used non-standard chips was in order to combat piracy, or because they were made specifically for SNES cartridges in limited quantities.

      Good question about the M27c160, I don’t use them because I have heard that they don’t work (http://nintendoage.com/forum/messageview.cfm?catid=22&threadid=102916). It might be that they can be made to work, but as I said at the start of this tutorial – this is simply a guide for the method that works for me. If you managed the get a 160 working then I would be very interested in seeing it! Good luck with your future work.

      Thanks
      Jack

  11. Nilton says:

    Undoubtedly best tutorial on Repro SNES!
    I’m waiting deliver my components, to make my first cartridge.
    thank you so much. 😀

  12. Jaime Diaz says:

    Hi. First of all just want to say great tutorial, i’ve already made quite a few repros following your guide. I’m having a problem with a copy of Parallel worlds however. So i’ve already made 1 copy of the game and it works fine. I was trying to do another one yesterday and when i was desoldering I noticed, one of the traces lifted, it didnt break off or anything just the circle part of the trace lifted so i pushed it down and it stayed in place. So anyway I tried to solder both chips in, I used troy aikman football as my donor, Now when I boot up my game i get the -euclid- intro logo, then the noise of a heart being filled up and it crashes to black screen, lol. Just wondering if maybe that lifted trace ruined the board? or maybe i can rewire the one pin to another point on the cart? everything else checks out fine i used the same bin files for my first copy, checked my eproms beforehand to ensure they were all empty, etc. Any help would be greatly appreciated.

    • jaskamakkara says:

      Hi Jaime,

      The lifted trace could be a problem, I suggest visually tracing it to another exposed pin on the board and testing the continuity with your meter, if the continuity has been broken then rewire the trace using some thin gauge wire (Kynar, for example) being sure to keep the wire as short as possible.

      Other than that, it’s hard to say what could be wrong – try cleaning up all the contacts on the PCB with some contact cleaner and double check your soldering with your meter, making sure also that you didn’t bridge any pins.

      Are you using a PAL or NTSC donor cartridge? Just be sure that the region of the donor matches the region of the game ROM.

      Good luck, and let me know how you get along.

      Regards
      Jack

      • Jaime Diaz says:

        I’m using an ntsc donor. I bought a few more donor carts I’m going to first try my eproms on one of those, if i get the same errors i’m just going to assume the eproms were bad.

        • Jaime Diaz says:

          So I ended up lifting the pads on another donor lol. but anyway i just followed the trace to the next pin and rewired the eprom to that pin and it worked. Now another problem im having is during the intro sequence to parallel worlds the graphics are glitched, and its the same on the two copies i have made. I’ve loaded the rom into an emulator and seen no glitches, so I’m wondering if something is going wrong when i split the rom into 2 parts or maybe programming? the game otherwise works fine.

          • jaskamakkara says:

            Good to hear you got it working. Weird about the graphic glitches though…

            Which emulator are you testing the ROM in? You will want to check it in bSNES (now part of Higan) as this is the most accurate emulator around – programs like ZSNES might give you better results than the actual console would.

            I doubt it’s anything to do with the ROM splitting, but I could be wrong. If you’re doing it with SNES ROM Utility then I can’t envisage any problems.

            Sorry I can’t be of much more help than that – it’s hard to say, I’ve never had one that worked but with graphical issues before.

Leave a Reply