Question about donor-cartridge for altered SMB2-game

[southrend]

Hi all,

I've got the following situation. I'm 'making' my first custom game, it's going to be a present for someone. I've changed most of the sprites in Super Mario Bros 2 (and if I've got some time left, i'm going to try to change the music). I want to make a real cartridge out of this, but I'm not sure what donor-cartridge I should get. I think I can just use a Super Mario Bros 2 cartridge but I'm trying to get the cheapest game-cartridge I can find.

So that leaves me with a couple of questions:

1. Since I'm only changing the graphics (and music) in the game, do I still need to look for a donor-cartridge as if I’m trying to make a SMB2 repro?
2. The game needs to be played on a European NES, that’s why I’m changing a PAL-version of the game. Do I need a PAL donor-cartridge or is there no hardware difference?
3. What would be a suitable donor-cartridge? I know there are some certain things I need to look for such as hardware (MCC3A), iNES Mapper (4) and perhaps PCB Class (NES-TSROM). When I search the Bootgod database for these options, I only get 3 carts (All of them are SMB2). However when I do not search for NES-TSROM, I get 47 hits. Are those games suitable as donor?
4. I’m going to burn the rom on 2 27c128 Eprom-chips. I believe they are 28-pins so those should fit perfectly in a cartridge? Or do I still need to rewire some pins?

Thanks for looking, I'm looking forward to the answers

~Southrend


EDIT: I thought I was putting this in the Newbie subforum. If this is the wrong subforum, could someone please move it?

[lidnariq]

Since I'm only changing the graphics (and music) in the game, do I still need to look for a donor-cartridge as if I’m trying to make a SMB2 repro?

If you only change the graphics, it'd be easiest to start with a copy of SMB2, because then you'd only need to change one of the two ROMs.

Do I need a PAL donor-cartridge or is there no hardware difference?

Yes; US and PAL consoles use a different lockout IC. You should make sure that the cartridge works in the target NES—or else disable the CIC in that NES—before you do the other work.

What would be a suitable donor-cartridge? I know there are some certain things I need to look for such as hardware (MCC3A), iNES Mapper (4) and perhaps PCB Class (NES-TSROM). When I search the Bootgod database for these options, I only get 3 carts (All of them are SMB2). However when I do not search for NES-TSROM, I get 47 hits. Are those games suitable as donor?

You only need to care about TSROM. http://wiki.nesdev.com/w/index.php/TxROM TKROM would also be an acceptable starting place.

I’m going to burn the rom on 2 27c128 Eprom-chips. I believe they are 28-pins so those should fit perfectly in a cartridge? Or do I still need to rewire some pins?

You'll have to rewire things.
http://wiki.nesdev.com/w/index.php/Mask_ROM_pinout
Also, 27C128s are faaaaaaaar too tiny, they only can contain 16 KiB of data. For an SMB2 hack, you'll need to use 128 KiB ROMs, which come in 32 pin packages.

[mikejmoffitt]

If you want things to go easier, buy yourself a 29F010 / 29F020 / 29F040 5V flash chip, which are 1mbit, 2mbit, and 4mbit respectively. They are drop-in compatible replacements for the 27C010, 27C020, and 27C040 EPROMs, but can be erased nearly instantly and are much easier to write (no funky high write voltages like EPROMs or 28F* series).

You will have to do the same rewiring that you had to do for the EPROMs, but it is much nicer to work with the flash chips.

[Memblers]

I don't know about the other FlashROM sizes (never used them), but I'm certain that the 29F040 isn't a direct replacement for 27C040. One of my older boards needed a jumper for that. I looked it up, and A18 is pin 1 on 29F040 and pin 31 on 27C040. Pin 31 on 29F is /WE. It is the same otherwise, though. I don't get why they flipped those pins around like that.

[southrend]

Do I need a PAL donor-cartridge or is there no hardware difference?

Yes; US and PAL consoles use a different lockout IC. You should make sure that the cartridge works in the target NES—or else disable the CIC in that NES—before you do the other work.

So if I disable the CIC-chip I should be able to use non-PAL cartridges as my donor?

What would be a suitable donor-cartridge? I know there are some certain things I need to look for such as hardware (MCC3A), iNES Mapper (4) and perhaps PCB Class (NES-TSROM). When I search the Bootgod database for these options, I only get 3 carts (All of them are SMB2). However when I do not search for NES-TSROM, I get 47 hits. Are those games suitable as donor?

You only need to care about TSROM. http://wiki.nesdev.com/w/index.php/TxROM TKROM would also be an acceptable starting place.

You adviced a SMB2 cartridge because I only needed to change 1 chip, but I also made some changes to the layout of the titlescreen, so I would need to replace both chips anyway. So if I'd search on ebay for any of these roms I should be okay?


Also, that was a stupid mistake of mine for the 27c128's. Good thing I didn't buy those. I bought some 27c010's which I'm going to use. Thanks for the rewire-link!

[lidnariq]

So if I disable the CIC-chip I should be able to use non-PAL cartridges as my donor?

Yes, if you disable the frontloader's CIC, you can use out-of-region cartridges as donors:

Only three games (all official Nintendo multicarts) rely on the CIC's presence. (Nintendo World Championships—very narrow distribution, Nintendo World Cup/Super Smash V'Ball—US only, Nintendo World Cup/Tetris/SMB—PAL only; all will sometimes fail to go back to the menu when you hit reset)

You should be able to just cut pin 4 on the existing CIC, or if you want something that feels a little more robust, there's a few threads here about other workarounds:
* viewtopic.php?p=117410#p117410
* viewtopic.php?p=98891#p98891 (and viewtopic.php?p=99226#p99226 if you have one of the above three multicarts)

So if I'd search on ebay for any of these roms I should be okay?

Just remember that Famicom cartridges are physically incompatible with NES cartridges, and also remember that TKROM is just TSROM + a battery.

[Polar Hacker]

As a side note, the redesigned NES (The one with the top loader) does not have a lockout chip, so if your planing on playing it on that, there is no need to worry about the lockout chip. Just keep in mind if you play it on a different toaster NES, the lockout chip will need to be disabled, or you will need an adaptor.