If you guys

[Zhs2]

Calling all snarfblams to this thread. I repeat, calling all snarfblams. I vote that the next revision to Double Helix include an editor for the Metroid in Metroid: Zero Mission.

This bump hereby overrules all of the shittiness otherwise incited by Hacker347. If someone already suggested this I will kill people. 8)

[snarfblam]

Well, I had a look at the Zero Mission rom. I can't find any data from the original Metroid. Assuming that it is emulated, it must be compressed. That's my guess, anyways. If an unmolested ROM image can be extracted some how, the rest would probably be simple. So assuming it's possible, I would need some direction from someone familiar with this rom. Hmmmm....

[zephyrtronium]

7D80A0 -7F7733 - NES Metroid data

I believe the NEStroid code is compressed and software-emulated. Since the GBA natively supports three types of compression, it's likely that one of those types is being used. I'll open up MZM in NO$ and see what I can find out.

[Malpercio]

maybe comparing to the NES Classics release of NEStroid would help... either finding that code in the ZM rom or code that matches the original Metroid's code.

[zephyrtronium]

I spent a lot longer in NO$ than I thought I would and didn't find out much. I did stumble upon an LZ77 decompression call, though, and the CPU had a higher load in NEStroid than at almost any time in normal play in MZM, so code being decompressed and emulated seems, at the very least, plausible.

[snarfblam]

Silly me. I should have thought to check data crystal.

Well, is there anyway to play NESTroid in a GBA emulator without beating the game? I'd like to examine the RAM and see if it is actually working with the original ROM data.

(Edit) Nevermind, got it.

3000018     Sound test + original Metroid

    * 1 for original Metroid
    * 64 for sound test

[snarfblam]

Well, in the ROM at 0x7D80A0 there is some kind of header or something for the ROM ("NES METROID" in ASCII appears at that location), and the NES Metroid ROM image (or part of it) is being loaded into RAM at 0x027DC000, but I can't figure out how it's getting there. I have virtually no GBA experience and all I have for a debugger is Visual Boy Advance, which is practically useless. I can't find a compressed data header in the vicinity of "NES METROID", and I searched for the first few bytes of the NES ROM, which should be present at the beginning of an LZ77 stream (I think), and found nothing. So... i dunno.

[P.JBoy]

Awesome, another GBA ASM guy, some onto #jzd and/or #metconst on irc.esper.net

[Zhs2]

Uhh, PJBoy, he's an NES man :pwuh:

[P.JBoy]

Meh, good enough