Building a map based on a ROM image: hidden message from the gods in Maze of Galious

Resident (34)

29-06-2021, 22:57

A quick check doesn't show anything. The value (e054+e055 for Popolon exp and maxexp respectively) is twice read as a word from e054, but only ever written to as a byte. So e055 is never updated. It's possible that I have missed some (index) pointer operations, but I don't expect it. So it looks like they just used the same code as for drawing VIT, which explains why they can draw the max line. That would also explain why the value is in memory in the first place.

Par Manuel

Ascended (19679)

29-06-2021, 23:35

Can you tell me something about what is in the ROM? How crammed is it? How much is in it for map-data, enemy-data, code, music-data and graphics? So how is that 128kB divided amongst these categories?

Par Bas Wijnen

Resident (34)

30-06-2021, 09:33

I haven't made an overview, so I don't really have an idea of that right now. But I think I'll do it for the video. It looks pretty crammed. There seem to be some areas which are empty, but also lots of data is stored with compression to save space. My impression is that that was needed to make it fit, but as I said I haven't really checked.

Par Manuel

Ascended (19679)

30-06-2021, 10:45

IMHO there's an amazing amount of content in this 128kB The only critique: it could have used a bit more variation in musics. E.g. each world to have its own music. But I'll forgive them for that.

Par santiontanon

Paragon (1832)

30-06-2021, 14:46

I would also be curious to learn about that! And you mention some data is compressed, I wonder which compression scheme did they use?

Par Victor

Champion (509)

30-06-2021, 18:19

santiontanon wrote:

I would also be curious to learn about that! And you mention some data is compressed, I wonder which compression scheme did they use?

We've created a simple JAVA compression routine with the same result. That's to respect how KONAMI compress GFXs...

It's simple... KONAMI compression routine

Par santiontanon

Paragon (1832)

30-06-2021, 19:50

Thanks! I am at work now, so I cannot see .rar files (RAR is very unfriendly to non-Windows machines btw ). But I'll check it out when I get back home.

Par santiontanon

Paragon (1832)

01-07-2021, 05:30

Thanks for sharing the code Victor! I just had a look, and now I see it's RLE encoding. Very common in the 8bit/16bit era (the PCX format commonly user in Amiga, for example, also used this encoding). Thanks for sharing!! Very cool to know what method was used.

Par thegeps

Paragon (1256)

01-07-2021, 06:56

I'd like to see the video. +1 for YouTube one

Par ro

Scribe (5061)

01-07-2021, 10:55

I feel the need for an "KonamiMsxArchive" sorta gitbub/website comming up; reversed engineered Konami titles. There're several other projects like this, think of the disassembly project of Metal Gear for example. This is just lovely stuff for us coders