GBA Famicom mini series

General No-Intro related discussions.
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tomfung
Posts: 2
Joined: 24 Jul 2008 18:01

GBA Famicom mini series

Post by tomfung »

No-intro had cut the roms on 200X, and later no-intro keep the 4MB copies. I remember that the good dump should have 4 copies itself, only 4MB roms will work on real gba
Hiccup
Datter
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Joined: 09 Oct 2015 11:29

Re: GBA Famicom mini series

Post by Hiccup »

The actual ROMs (for most of them) seem to be 1MB - this is what is written on the ROM chip. If it doesn't work on an emulator/flash cart, this is because it does not emulate the cart properly.
KingMike
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Joined: 22 Sep 2012 16:36

Re: GBA Famicom mini series

Post by KingMike »

I'm not seeing where it specifically says 1MB on the chip.

I have two of the games.
Metroid: AGB-FMRJ-0 H2 R26V3211F-0MI 430A204
Nazo no Murasamejo: AGB-FNMJ-0 H2 R26V3211F-0M5 433A207
https://imgur.com/a/kO5refB

Now a quick Google search doesn't turn up maker info for that particular type of ROM, but that "32" in the part number is pretty suspicious.
I have a feeling that since GBC games have been confirmed 1MB minimum (through at least one developer rant hidden in space-filler data) and that no GBA games have been confirmed under 4MB, it really feels like 4MB was the official minimum size.

Just opened the Metroid Famicom Mini ROM in a hex editor. If it was supposed to be 1MB, I would expect repeating or 00/FF data after the $100000 mark, but I don't. Even just checking for the header title "FMS METROID", the only hit I see is in the header. I expect it would be possibly mirrored as an alternate. As I recall, GBA games have just returned FF data when overdumped beyond the used data.
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BigFred
High Council
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Re: GBA Famicom mini series

Post by BigFred »

Most Famicom Mini releases are based on NES ROMs. Those consist of 4 times repeated data. At first it was believed to be mirrored data in the chip. Zelda had some kind of protection scheme that prevented the game to be running properly at 8 MiBit. Then a patch by Rising Sun addressed this issue which indicated Nintendo included a size check.

However it turned out the data is just 1 MiB and there is some mirroring on the fly causing this behaviour.

Some FM releases like Metroid however are based on FDS images. These do indeed contain 32 MiBit of data.
Hiccup
Datter
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Re: GBA Famicom mini series

Post by Hiccup »

The MX chips have a code written on them that includes size info:
MX???SSS?

MX = identifier
? = unknown
S = Size, "aligned" to the left with zeros as padding, e.g. 800 = 8 mebibits
KingMike
Posts: 586
Joined: 22 Sep 2012 16:36

Re: GBA Famicom mini series

Post by KingMike »

BigFred wrote: 28 Oct 2020 06:54 Most Famicom Mini releases are based on NES ROMs. Those consist of 4 times repeated data. At first it was believed to be mirrored data in the chip. Zelda had some kind of protection scheme that prevented the game to be running properly at 8 MiBit. Then a patch by Rising Sun addressed this issue which indicated Nintendo included a size check.

However it turned out the data is just 1 MiB and there is some mirroring on the fly causing this behaviour.

Some FM releases like Metroid however are based on FDS images. These do indeed contain 32 MiBit of data.
Yes, the two Famicom Mini games I have are from the FDS series (the third and final set of 10 games)
(the Japanese FM Metroid was the only FDS-based release. Even the Japanese release of Zero Mission contained the NES version of Metroid.)
endrift
Dumper
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Joined: 21 Oct 2015 02:07

Re: GBA Famicom mini series

Post by endrift »

I can confirm that the FDS series games use 4 MiB (32 Mbit) ROMs, however photos of non-FDS series ROMs show different chips that are 8 Mbit instead. Super Mario Bros 2 (21) Akumajou Dracula (29) and SD Gundam World - Gachapon Senshi Scramble Wars (30) appear to be exceptions, but I don't have a copy of them so I can't confirm. But the fact that all but 22-28 mirror every 1 MiB is a pretty good indication that they're actually 1 MiB.
BigFred wrote: 28 Oct 2020 06:54 However it turned out the data is just 1 MiB and there is some mirroring on the fly causing this behaviour.

Some FM releases like Metroid however are based on FDS images. These do indeed contain 32 MiBit of data.
"On the fly" probably just means the upper bits of address just aren't connected to the physical ROM. Since the upper bits are consequently ignored, the end result is that they mirror. This is pretty normal behavior for systems with inconsistent chip sizes, just not for GBA.
battousai_hades
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Joined: 04 Nov 2020 23:59

Re: GBA Famicom mini series

Post by battousai_hades »

As i saw in cutting room floor, the cartridges contain a rom of nes and one emulator. What prevents the rom from being extracted and dated in the nes .dat?
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dreimer
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Re: GBA Famicom mini series

Post by dreimer »

Nothing does stop you. It's not super easy, but nothing impossible either: https://www.zophar.net/forums/showthread.php?t=1775
Here you can see how some guys extracted a bunch of NES ROMs from Classic NES Series / Famicom Mini Series. Already thought about doing the same in the past, but there are still some topics left of such extractions I wanna see datted before I fire another shot. ( There are even more you can go on datter's nerves with though: https://wiki.no-intro.org/index.php?tit ... ROM_images ) Feel free to do so. Get the GBA ROMs and then happy extracting :D
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