Megaman 2 whitout Chr

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ScarletDreamz
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Megaman 2 whitout Chr

Post by ScarletDreamz » Sat Mar 31, 2012 7:23 am

so i found a guide "Basic Nes Reproduction" and i saw the method to split the chr and the pgr from a nes rom, (btw im prety dam new to all this, and i mean it) so i decided to give it a try and get my rockman exile rom working on my nes.

when i run trought tnines.exe or nes mapper program. it tells me that my rom has no chr. only Pgr, and some donation catridge for this would be:
Final Fantasy, Mega Man 2, Blaster Master, Metroid, Kid Icarus, Zelda, Zelda 2, Castlevania 2.

so i got some question, and remember that im pretty new to all this, but i like to learn and try.

so first of all, do i alwayes need to remove the nes header?
what about the chr. if i use one of those donation cartridges would i only need to use the pgr rom, like, no need to touch the other components?

also the pgr size it says its 256kb (16 x 16kb pages). this means i only need one eeprom of 256 right? and i dont need to concatenate the pgr right?

i also was reading somethign here today from a final fantasy II cartridge is it gonna be like that?
thanks to all for the help C:

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tokumaru
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Re: Megaman 2 whitout Chr

Post by tokumaru » Sat Mar 31, 2012 8:00 am

ScarletDreamz wrote:so first of all, do i alwayes need to remove the nes header?
Yes. The purpose of the iNES header is to describe the cartridge used by the game so that the correct environment can be setup for the game in emulators. When the game is already in a proper cart, there's no need for such a header.
what about the chr. if i use one of those donation cartridges would i only need to use the pgr rom, like, no need to touch the other components?
Yes. Games that don't use CHR-ROM use CHR-RAM. This means that the board has a RAM chip in the place reserved for the CHR on the board. Since RAM is volatile, when the console is powered up that memory is empty, and the game program (which runs from PRG-ROM) is the one responsible for filling it up. This means that both PRG and CHR are inside the PRG-ROM chip, so that's the only one you have to replace.
also the pgr size it says its 256kb (16 x 16kb pages). this means i only need one eeprom of 256 right?
Right. But be careful when you buy your chips, because the numbers used to name them are in kilobits, not kilobytes. For example, a 27c256 doesn't have 256 kilobytes, it has 256 kilobits, which translates to 32kilobytes. So, for a 256kilobytes game you'll need a 2 megabits (or larger) chip.

ScarletDreamz
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Re: Megaman 2 whitout Chr

Post by ScarletDreamz » Sat Mar 31, 2012 8:33 am

Thank you so much for ur answer, so far im about to get a willem programmer and som chips, sadly i dunno what chips to use, mind giving so models or some help here? C:

Bwt i already this:

27C256, 27C512, 27256 and 27512 are 28-pin EPROMs that are pin-compatible with the Nintendo Mask ROMs. Anything larger (the 1MBit versions 27C1024 or 27C1001 for example) are 32-pin EPROMs. They are not directly pin-compatible with Nintendo Mask ROMs, and some rewiring is required.

so im gonna need to rewire some parts? since im gonna need to use 2mbits chips?

the 2megabits are labeles 27c2048 right? are there any other chips or only the 27c labeled?

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tokumaru
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Re: Megaman 2 whitout Chr

Post by tokumaru » Sat Mar 31, 2012 10:03 am

ScarletDreamz wrote:i dunno what chips to use, mind giving so models or some help here? C:
I use mostly Flash, and the 29Cxxx chips are great. I believe most chips will work on the NES.
so im gonna need to rewire some parts? since im gonna need to use 2mbits chips?
Yup. The pin configuration used in Nintendo chips isn't the same one used in EPROMs and FlashROMs, so you'll have to compare the pinouts, bend up the pins that don't match and solder wires to them, and then connect the other end of the wires to the correct roles/signals on the board.
the 2megabits are labeles 27c2048 right? are there any other chips or only the 27c labeled?
I believe some chips do have "2048" at the end, but some use "020". 27 is usually EPROM, 28 and 29 are usually Flash. Both kinds work on the NES (and EEPROMs too), so it's up to you to pick what kind of memory you want to use.

EPROMs (the ones with UV windows) are usually chosen for definitive carts, but Flash and EEPROM are more recommended for programmable carts because they can be erased in seconds, as opposed to minutes under dangerous UV light like EPROMs.

ScarletDreamz
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Post by ScarletDreamz » Sat Mar 31, 2012 10:22 am

i found this http://www.54.org/sage/condev/ff2cartproject/

since it uses mmc1, same as megaman 2, think i can use that one to do THE EXACT same thing?

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bigjt_2
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Post by bigjt_2 » Wed Apr 04, 2012 9:04 am

ScarletDreamz wrote:i found this http://www.54.org/sage/condev/ff2cartproject/

since it uses mmc1, same as megaman 2, think i can use that one to do THE EXACT same thing?
They use the same mapper, but the board layouts are different.

Mega Man 2

Your best bet would be to find a donor cart that has the same board layout.

SG-ROM Serach Results on Bootgod

Hell, you could just use a Mega Man 2 cart as an actual donor cart. Usually that' game's not terribly hard to find or that expensive.

I'm not finding an SG-ROM conversion onDrk's document, though. Is it actually the same as one of the other Sx-ROM boards that MMC1 uses? Or is the same conversion as one of these listed possible?
Last edited by bigjt_2 on Wed Apr 04, 2012 10:38 am, edited 1 time in total.

tepples
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Post by tepples » Wed Apr 04, 2012 9:47 am

For SGROM or UOROM, use SNROM. SGROM is just an SNROM board without the PRG RAM holes.

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MottZilla
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Post by MottZilla » Wed Apr 04, 2012 11:52 am


ScarletDreamz
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Post by ScarletDreamz » Thu Apr 05, 2012 6:18 am

replying to the last answer, it would be awsome to start from scratch using one of thos mobos for the nes, but since im pretty newbie i prefer to start with something already labeled, and answering the past question, i do got a megaman 2 copy and also a faxanadu copy, both got the same label, so, now that i got that, it means i just need to burn the chr into the chip, and its gonna be ready to play? or i need to cut conection or sold pins?

3gengames
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Post by 3gengames » Thu Apr 05, 2012 6:22 am

LOL, the first baby step if buying those boards and putting the chips right on it, as they don't need rewiring at all and is very very simple. If you use Nintendo boards, you will have to rewire them all. Except a few <=32KB each chip. And you can put the retrousb boards in a real case AFAIK.
Last edited by 3gengames on Thu Apr 05, 2012 6:46 am, edited 1 time in total.

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tokumaru
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Post by tokumaru » Thu Apr 05, 2012 6:28 am

ScarletDreamz wrote:but since im pretty newbie i prefer to start with something already labeled
Actually, being a newbie is more of a reason to use a RetroZone board, since it already has the correct pin layout for EPROMs, so you don't need to rewire anything.
it means i just need to burn the chr into the chip, and its gonna be ready to play?
You mean PRG, right?
or i need to cut conection or sold pins?
Anything larger than 32KB (or is it 64KB? Not many NES games are 64KB anyway) needs rewiring.

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MottZilla
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Post by MottZilla » Thu Apr 05, 2012 10:37 am

And please don't butcher good games for your home made projects. If you're going to do it, please pick a very common game that sucks. Mega Man 2 is one of the best games for the NES.

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