Many of the rom-hacks for NROM games expand the filesize of the original rom.
Is there a way to expand an NROM-256 board to accept more than 32kB PRG and 8kB CHR? Or is it possible to use UxROM board for mapper 0 roms?
Thanks in advance!
Does it only expand the PRG data or do you need to expand CHR as well?
By definition it wouldn't be NROM anymore once you added more than 32/8 KB that's all there is for addressable non-switching address space.
If the hack only expanded the PRG data (and the rom was modified/re-hacked accordingly) you could put it on a UNROM board and just use a ROM for CHR data instead of RAM.
But if you needed to expand both PRG and CHR you'd have to go to something like MH-ROM or MMC1 or something. Here again if the hack is written for mapper 0 but violates 32/8 available on the hardware, you'll have to re-hack the game to get it to work... Since the original hack wasn't written to work with the new mapper the game won't work.
So I guess the short answer to your question is really no... Atleast that I can imagine. I'm not sure how emulators handle the larger NROM games, I'm guessing they just don't limit the max addressable space to $FFFF, so addresses like $10000 that don't exist on the NES still work on emus?
Thanks for the answer, luckily the IPS patch expands PRG only. So exchanging the RAM for CHR on an UNROM board should work?
I can see that
6264 is pin compatible with 27C064, so it shouldn't be a problem...
Nestopia states "non-standard NROM") [EDIT: not true!]
Make sure the PRG data isn't simply mirrored or something. Expanding the PRG without changing the mapper to something else than NROM doesn't make any sense at all.
What hack is this?
Like it's been said, if the PRG-ROM is larger than 32KB it's not NROM anymore. If the PRG has been expanded to more than 32KB, the game must have been mapper-hacked as well, or else it wouldn't work even on emulators. Since NROM doesn't offer any form of bankswitching, the emulator wouldn't even know how to use the extra PRG.
Open the hack in an emulator and check what it says about the mapper. You have to use whatever board the emulator says the ROM is using, even if you know that the original game was NROM. EDIT: I saw you mentioned Nestopia saying it's "non-standard NROM", which is really weird. Yeah, I guess we can't help any further unless we know what game/hack this is.
Oh I'm sorry, again I'm writing something I have in my memory and don't tripple check in reality if that's correct...
I was talking about a SMB rom hack (DX somehting) but now I tested it and it's writing SxROM (non standard). But I see that no-standard is only the nonstandard PRG size, otherwise is a normal MMC1 game now.
Thanks guys for trying to help me. I'm now searching like crazy for that smb hacks that enlarge the original rom. But so far every one that does that changes also the mapper... usually TxROMs and SxROMs.
jpx72 wrote:
But so far every one that does that changes also the mapper... usually TxROMs and SxROMs.
That's the only way they'll work. If the header said "mapper 0" and there was more than 32KB of PRG, the emulator simply wouldn't know how to use the extra memory, because mapper 0 doesn't offer any kind of bankswitching. That's why I doubt you will find any working hack like that.
jpx72 wrote:
I'm now searching like crazy for that smb hacks that enlarge the original rom. But so far every one that does that changes also the mapper... usually TxROMs and SxROMs.
Why are you looking so hard? Wouldn't that be a BAD thing anyways? It's GOOD that they changed the mapper, because that'll allow you to build a working cart...
infiniteneslives wrote:
Why are you looking so hard? Wouldn't that be a BAD thing anyways? It's GOOD that they changed the mapper, because that'll allow you to build a working cart...
You're right, I just didn't wanted to look like a dork for making this thread (it's late for that anyway).
But yes, I'm quite happy now that it's like that
I thought it will be impossible but it's quite the opposite!
Perhaps someone wants a hack to expand SMB1 to use UNROM, which is probably the simplest mapper if you just want to expand PRG. The biggest reasons I see to use SxROM instead of UNROM in a hack of SMB1 are for 1. rapid tile rotation with CHR ROM (e.g. spinning coins and ? blocks of SMB3) and 2. support for battery-backed PRG RAM if a game needs to save more than 32 bits (typical password capacity) of state across play sessions.
The hack I was talking about in the first place was Kamikaze mario DX+ (
link to IPS patch). It's using SxROM after applying to SMB1.
Thank you all for explanations!