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Hey people, my friend asked me if i could put a hack onto a cart for him, and i remembered this place, so i thought this would be the best area to ask for help. Before anybody says, i did tell him about flash carts like the powerpak, gamedoctors etc, but he wants to give his older brother an actual cart (along with a game saver) to his brother for christmas.

He's asking me to put the Kaizo mario hack onto a SMW cartridge. I know when i try to change the EPROM I'll have to do a little rewiring. One thing I'm not too sure about is that SMW is 512KB, however the Kaizo I have is 2MB. Would I have to do any more wiring than usual, or will just wiring a 2MB eprom work? (Like a 27C040 from progshop, that place is reliable right?) Or would I need a different doner cart? I'm also looking at a Willem Programmer to do this. Is MCUmall a good place to get this?

I'm looking at This tutorial for rewiring. However it looks like it's setting it up for a 27C080, although the guide says it'll work with a 40. Would i just insert the 40 normally?

Sorry for the big text, i'm kind of a noob at building these . Any help would be appreciated

The 2Mbyte EPROM is the 27C160, it should work with the 16-bit adapter for the Willem programmer. You may want a different board, if the hack is 2MB then if there is a board that uses 2 ROMs, you could use 2 27C080s.

I'm not familiar at all with the different SNES board types.

You'll need a LoROM 2Mbyte game with 2Kb (or more) Battey Backed SRAM. Once you have that game cartridge, then you need to see if it has two 1 Mbyte MaskROMs or just one. If it has two you will need two 27C801s. If it has one you will have the option of two 27C801s plus some other chips, or just one 27C160.

Also, I recommend against buying any EPROM programmer that is not USB. I think MCUMall would be a good place to get a USB EPROM programmer but I haven't bought a USB EPROM programmer from them, only a serial PIC programmer which worked just fine. Just don't try to go cheap with a 30$ or 40$ cloned willem parallal port eprom programmer. They are terrible.

Allright, i think i found a suitable doner in Breath of Fire II. The information given by UCON says it should work, lorom (well it says it's not a hirom), 8 Kbytes of Battery SRAM, although just one part worries me a little.



the size below the name/company/region shows 12mb, although the internal size is 16mb. Would I go by the internal size or the other one when picking a game? Also a picture of the pcb i found online shows just one MaskROM. I would rather do it with as less of a mess as I can, so what would be a decent programmer for a 27C160? where can i get a 160? or if there's a decent price gap, how would the 2 chip solution work? Again I appreciate the help

Getting a programmer for a 27C160 will require either a very expensive programmer or a moderately expensive one with an adapter. Alternatively you can just buy the EPROM and pay the seller to program it generally for a small fee.

A single 27C160 is cheaper than two 27C801s. As far as the original cartridge, it depends on unknown factors whether they used two or one mask rom. The main thing for you is how ROMs are enabled. If you have two ROMs on the cartridge when the first 1Mbyte is accessed it's ROM Enable signal (or /OE signal to the ROM chip) is set. When the area beyond that is accessed the other /OE signal that connects to the second ROM would be set.

I suppose if you used 1 2mbyte chip you could make sure to wire all the usual signals up to either one of the sockets and then tie the /CE and /OE holes together and to the ROM chip and it would probably work.

I'm not really sure though because messing around with hardware isn't something I do much. If you use 2, 1mbyte chips it's more complicated unless the original cartridge also used 2.

With internal and actual size, 12mbit should behave the same as 16mbit.

Well, I found a different cart that can work. Same info, lorom 16mb, and this one has 2 Mask ROMs instead of 1 so I believe i could use 2 27C801s and a cheaper programmer. A couple of posts up you mentioned Willem clones. How do i know if they're a clone or not? And do you know of a programmer that will work with the 801's and is relatively cheap (<$100)? or would a real willem fit that? If i go the 2 chip route, would i solder both chips the same way over where the 2 maskroms were like the diagrams in the tutorial in my first post, or is the pinout different between the 2? Sorry if all the questions are a little annoying, but i just want to be absolutely sure i have the right info before i go out and buy the materials to do this.

Basically I wouldn't buy any programmers from eBay. Anything from MCUMall should be good. Stay away from anything that uses the parallel port, get one that only requires USB.

With two chips you will need to rewire both socket connections because EPROM and SNES maskROM pinouts dont match. You can solder the chips directly into the socket but then you will have to cut PCB traces and rewire things. Or you can solder them into the sockets with the pins needing rewiring bent up with a wire attached going to the correct spot. Alternatively you can connect the EPROMs with 32 wires each.

You do not want to use 27C040. Use 27C801s and you will use 2 of them for your 16mbit/2mbyte ROM.

Okay, today I'm going to my local retro shop to try and pickup the doner game, and if things go like i hope I'll be able to gather the money to buy a Willem USB programmer from MCUMall and a gamebit (or lighter) on Monday, if not sooner. I have just one final question about the actual pins on the ROM chip. How far can the pins be bent? can they be bent all the way upward or until they're straight out? And with the wires, i just solder them to the end of the pin and to the contact I believe (like in this 5-minute mspaint job, assuming the ROM chip is already in place save for the bent pins)

It's possible to bend them completely up and onto the top of the package. But you need to take care as it's possible you could cause too much stress on a pin and break it off and then you're really hosed.

When I did a NES cartridge with EPROMs I soldered the chip into the socket and bent the mismatched pins up 90 degrees (so they go out rather than down). It worked well for me.

Then after soldering all the matched pins from the solder side you can solder wires to the mismatched pins and then route the wires to the pin holes in the board where they need to go, push enough of the stripped wire into the hole and solder it in place from the other side.

Allright, when i get everything i need, i'ma try to post how my first time with this goes lol. Thanks alot for helping me out and Merry X-Mas 8)
EDIT: Got the game, also found 2 stunt race FX's (sadly i could only afford 1), so I'm also going to try to make star fox 2 eventually also noticed they had an fc twin and the other one that does genesis also.