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Author Topic: How to add foreign letters to a GAMEBOY game?  (Read 514 times)

Midday-Moon

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How to add foreign letters to a GAMEBOY game?
« on: June 26, 2021, 05:54:35 pm »
Hi,

Im romhacking beginner. The game in question is: Doraemon 2: Animal Planet Densetsu.
Im currently working on the Chinese version of this game. But I want to display the password in English letters on the screen.
Im currently using Crystal tile and Crystal tile 2.

Any ideas on how to do this? Also, does my english make sense?



FAST6191

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Re: How to add foreign letters to a GAMEBOY game?
« Reply #1 on: June 26, 2021, 07:18:57 pm »
That may be easier said than done as you are doing something a bit different to what people normally do when they ask about adding letters.

The password it displays is what the game converts back to hexadecimal when the player enters it back in. Looks like you have the font there so you can make it display whatever you want by overwriting. However you would then be faced with the issues of what the game displays when those characters come up in text, or you would have to alter how the game encodes and decodes a password which would be a fair bit of effort compared to editing fonts and text. If the password is always going to be within a range you might be able to put the English letters in that range and then put the Chinese characters in values outside it, and make your insertion table account for it.


Also crystaltile? I am surprised you can even find a copy of that these days. Don't think I even have a copy of that one (and I have crystalscript even).

Midday-Moon

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Re: How to add foreign letters to a GAMEBOY game?
« Reply #2 on: June 27, 2021, 12:35:36 am »
>FAST6191

Thanks, This is a list of passwords (17E00~17FF0), it will definitely be useful. What should I do if I want to change the English letters in the Japanese part here?


FAST6191

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Re: How to add foreign letters to a GAMEBOY game?
« Reply #3 on: June 27, 2021, 11:28:52 am »
What happens if you change the passwords in that list?

I am curious now as most times we have passwords it is literally a standin for hex wherein the data is used to generate the game state. If instead it is more of an unlock command (sometimes you get things telling a story or being jokes) that could change things, and I should probably have thought of that before.

Midday-Moon

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Re: How to add foreign letters to a GAMEBOY game?
« Reply #4 on: June 28, 2021, 06:57:25 am »
>FAST6191

If the password is changed, input the changed password to start the game on the way. For example, after changing the password from "あい" (Love) to "おの" (Axe), the player can start on the way to the game by entering "おの" (Axe). The kana syllabary of the password system can also be changed.

KingMike

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Re: How to add foreign letters to a GAMEBOY game?
« Reply #5 on: June 30, 2021, 01:05:02 am »
I'm not familiar with that game, but I can tell you that, especially on 8-bit consoles like Game Boy,
hacking a Chinese version is probably harder than working on the Japanese original.
Particularly as most/all Japanese GB games tended to use 8x8 kana for text, which is FAR better for English on such a low-resolution screen.
Chinese games (which I think tended to be unofficial translations, I don't know of any GB games which had a licensed Chinese localization. I think they the library of official releases mostly used English ROMs, and the one licensed game I have, Super Chinese Land 3, is binary identical to the JP version) usually modified the fonts to 16x16 to use kanji, but that is, again, way too large and space-wasting for any kind of sensible English translation to fit the screen space.
I think the reason to even consider CH would be if, as Dynamic-Designs originally played to do with Destiny of an Emperor, simply because it would've bypassed font compression in the JP original (which by this point, there's probably enough GB ROM hacking expertise to make that less of a concern).

But, as to actually answer the question...
how a password screen works is that indeed there usually is likely two text tables in the ROM.
One to print the menu text on the screen, and another table to indicate which character is mapped to each possible highlight point on the screen.
(so say, for the first, you might have "A B C D E" because on the screen characters are printed with spaces between to have room for a cursor. And then for the second you would, usually near it, have "ABCDE" to represent that those first five spaces should map to characters A, B, C, D and E.)
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