Prototype '0429' from Ecco II for Genesis/MegaDrive has been released, and the documentation and ROM file can be found here: http://www.ecco-darksea.com/?p=134

In order to concentrate discussion of this prototype and best revise the docs, I'm making this thread. Enjoy

Awesome, but the forum is infested with porn bots

Epicent, the song 14, 09,16 on 429 are different than final.
14 has an annoying buzzing on the first playthrough that continues (quietly) through the rest of all the playthroughs, 09 starts differetnt and it's electric guitar lyrics start at the beginning (Just like X11!) 16 has the bloop notes( My music education is horrible, don't know the instrument.) echoed

I've started a disassembly of this particular Ecco revision a few days ago. So far all (or almost) all code and data have been separated wth the exception of the Z80 pieces which are still marked as unknown.

Labels/Functions/Variables aren't named at all (besides a very few of them): these will come in due time, as the code gets understood.


Anyway an interesting find: in 0429 or X11 (maybe others) you can type the word EASY (left aligned, rest of the caracters are irrelevant) to activate some kind of easy mode and start at homebay (X11 sets the "Easy Game" flag to 128 after doing this)


EDIT: so at 0xCFFB8 we have the PasswordChecker subroutine which analyses the code and decides where to throw ecco into (level #ID retuned in d0).

It starts by reading all chars except the fourth and sum their values (A = 0 ... Z = 0x19) then divides the result by 0x1A. So for a password of "BBBBBBBB" we have (1+1+1+1+1+1+1)/0x1A = 0. This number is then compared to the 4th char (bolded) but not directly: the fourth char is scrambled and it's decoded by a lookup table:



Ths means that 'A' is infact 'M' (code 0x0C), 'B' is infact 'C', and so on.... So Our 7 letters summed together and divided by 0x1A have to be equal to the descrambled 4th lettercode to pass the first validation test and get further... In our case of "BBBBBBBB" it fails the check, but "BBBWBBBB" passes the first phase (but not the rest )...

Bump, the disassembly continues... I just found that the demo recording is called by holding B before the SEGA logo appears, and the palette looks like shit (it's using a RGB color test palette or something instead of the usual blue colors:

Not really usefull as it still tries to write into rom area which is forbidden in emulators. The recording address can be changed in an HEX editor at 0x3140

Also tihs function isn't called on Ecco 2 final EU

None of the demo editors ever seem to bother to set the screen palette. All the way back to Ecco 1 rev00, they'll just keep whatever is already on screen, and... well, you know the rest here.

Well after much time doing noth... err I mean other stuff, I decided to release the disassembly file, but beware: it's very incomplete , but all the 68k code/data seems to be all properly separated.

Grab it here (it's only openable in IDA)

I will keep updating it.