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Author Topic: How do you make an SRAM hack?  (Read 7376 times)

PKstarship

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Re: How do you make an SRAM hack?
« Reply #20 on: September 25, 2015, 04:00:42 am »
It isn't possible to fit all the NES Mega Man games into one cart, is it? That would be my dream hack, Mega Man 1-6 in one cart with SRAM.

FAST6191

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Re: How do you make an SRAM hack?
« Reply #21 on: September 25, 2015, 05:05:22 am »
As some kind of mapper merge... I would be impressed.

As a variation on the basic theme of flash cart. Why wouldn't it be?

Disch

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Re: How do you make an SRAM hack?
« Reply #22 on: September 25, 2015, 11:56:19 am »
If you're going to make a multicart, MMC5 would be the wrong mapper.  You'd be better off with one of the multicart mappers.  See mapper 45.

And yes it'd be possible.

KingMike

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Re: How do you make an SRAM hack?
« Reply #23 on: September 25, 2015, 12:14:29 pm »
It isn't possible to fit all the NES Mega Man games into one cart, is it? That would be my dream hack, Mega Man 1-6 in one cart with SRAM.
Minus the SRAM part, Chinese pirates have already done that.
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PKstarship

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Re: How do you make an SRAM hack?
« Reply #24 on: September 25, 2015, 01:12:51 pm »
I know, I found a ROM dump of the Rockman 1-6 pirate cart on a japanese site, but it stopped working after my emulator was updated :(

RetroRain

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Re: How do you make an SRAM hack?
« Reply #25 on: September 25, 2015, 02:47:10 pm »
PKstarship, out of curiosity, which Megaman game did you want to do a SRAM hack for?

PKstarship

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Re: How do you make an SRAM hack?
« Reply #26 on: September 25, 2015, 03:02:44 pm »
Probably Mega Man 5 first. It's the easiest to just pick up and play, I feel it would be very well complimented by a save feature, especially for people like me who play games on their phones or tablets :)

ShadowOne333

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Re: How do you make an SRAM hack?
« Reply #27 on: September 25, 2015, 04:18:59 pm »
Megaman Origins is a "finished" hack, as far as I'm concerned.  If I were to ever make a hack that had Megaman 1, 2, and 3, I'd have to do a few things:

- Re-convert Megaman 1 to CHR-ROM (since it only exists as CHR-ROM in my Upgrade Patch), and simply make it a CHR-ROM conversion, with no other alterations.  It would obviously use MMC5.

- Megaman 3 would then need to be converted to MMC5.

After those two things are done, I would then have Megaman 1, 2, and 3, all having the same mapper and using CHR-ROM.

Then I'd put it all together, and just like I did with Megaman Origins, I'd make a special bootup screen, and then the hack would be called The Wily Wars.

So yeah, if I ever decide to make 3 games in 1, it will be a NES version of The Wily Wars.

That's if I decide that I want to do it.  I haven't entirely ruled it out, but I pulled my Megaman Origins hack for a reason, since the patch essentially contained the ROM file data for both games, which it did not even occur to me until someone told me about it.

So for legal reasons, I decided not to do anymore multi-cart hacks.

Well, I am not so sure about RomHacking.net's policy there.
Did you remove the link because of a notification by the site, or just because someone else told you it had the ROM in the compilation?

I think we may need some further notice by someone in charge over here regarding that.
As far as I know there SHOULD BE NO problem with that, since RH.net already has quite some compilation hacks, like the Super Mario All Stars NES hack here:
http://www.romhacking.net/hacks/2422/

That one's been there for almost 6 months now and there seems to be no problem.
So yeah, I don't think the policies of the site affects such kind of hacks.

Even if the site denies it, there is still the option to post it somewhere else. :P

STARWIN

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Re: How do you make an SRAM hack?
« Reply #28 on: September 25, 2015, 07:46:38 pm »
Any compilation hack that only requires one of the games as a base sounds like it would be against RHDN policy.

However if you require the user to for example "compress" the source games (with specified filenames and checksums given..) into one file with no compression ("Store" compression level in 7zip?), then you might be able to create a small xdelta patch that transforms that into a multicart ROM. A bit difficult to say if the procedure would break with a new 7zip version though.

henke37

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Re: How do you make an SRAM hack?
« Reply #29 on: September 26, 2015, 05:22:09 am »
Probably better to provide your own patcher that accepts multiple source files.

snarfblam

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Re: How do you make an SRAM hack?
« Reply #30 on: September 26, 2015, 12:42:22 pm »
And in case anyone thinks that sounds too complicated, it'd probably be as simple as splitting and stacking the ROMs and then applying an XDelta patch.

ShadowOne333

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Re: How do you make an SRAM hack?
« Reply #31 on: September 26, 2015, 01:05:51 pm »
I agree, an XDELTA patch should be the way to go for this kind of hacks to avoid any issue.

RetroRain

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Re: How do you make an SRAM hack?
« Reply #32 on: October 02, 2015, 03:09:22 am »
If you're going to make a multicart, MMC5 would be the wrong mapper.  You'd be better off with one of the multicart mappers.  See mapper 45.

I looked into mapper 45.  The only problem with that mapper (which is probably the same for the standard MMC3 I would imagine), is that it only supports up to #$80000 bytes of PRG-ROM.  I experimented with it, and the hardwired banks always load 0x7C010 - 0x8000F.  And Megaman 1, 2, and 3 combined, easily surpass that.

If MM1, 2, and 3 were to be put into a single file, unless there is another mapper that supports a minimum of #$A0000 bytes, they'd all have to be MMC5 mappers.

Converting MM3 to MMC5 would be a piece of cake.  The real work would come from MM1, in which case the whole ROM would need to be re-converted to CHR-ROM, and that's just something I do not look forward to doing.  It was a pain in the ass the first time around.  Granted, it would most likely be easier and faster for me if I were to do it a second time, since I've got the experience now, but it's not something I look forward to doing.  CHR-ROM conversions are A LOT of work.  I've done three of them already.

It would be nice if you could toggle between CHR-ROM and CHR-RAM during runtime.

Disch

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Re: How do you make an SRAM hack?
« Reply #33 on: October 02, 2015, 11:01:16 am »
I looked into mapper 45.  The only problem with that mapper (which is probably the same for the standard MMC3 I would imagine), is that it only supports up to #$80000 bytes of PRG-ROM.

An existing mapper 45 game, Super 8-in-1, has twice that.  It's 1 MB PRG and 1 MB CHR -- the same max you'd have on MMC5.  And I'm not even sure that's the actual max for this mapper.

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I experimented with it, and the hardwired banks always load 0x7C010 - 0x8000F.

Ehhhh... you must have been doing it wrong.

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Converting MM3 to MMC5 would be a piece of cake.  The real work would come from MM1, in which case the whole ROM would need to be re-converted to CHR-ROM, and that's just something I do not look forward to doing.

Yeah converting MM1 to CHR-ROM would have to be done regardless of whether you went with 045 or 005.

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It would be nice if you could toggle between CHR-ROM and CHR-RAM during runtime.

Some mappers allow it.  019 comes to mind, but I don't think it has the PRG/CHR size requirements you'd need for a multicart.