Investigate what's needed to maintain trade compatibility

[andiemmadavieswilcox]

Overview

...as well as potentially other compatibility concerns (see compatibility section in repo's README). I would imagine something like keeping Pokémon data stored at the same memory addresses would likely be a key factor, but this is just speculation.

Purpose

Trade compatibility is one of the project's key goals, so it's important that we get as much information as possible about how to maintain said compatibility before we start editing the code.

Notes

I know that there are problems with being able to trade between different languages of the early Pokémon games, so this could be a good starting point for researching the reasons why.

Tasks

• Research to uncover the main reasons.
• Document the findings in the wiki.

[andiemmadavieswilcox]

The trade issues between Japanese and non-Japanese versions do indeed seem to be primarily due to changes in the memory (RAM, not ROM) layout, as corroborated by this PokéBase Q&A and this Bulbapedia article:

PokéBase:

Bulbapedia:

[andiemmadavieswilcox]

Given this new information, we should aim to not touch the existing layout where possible, which shouldn't be an issue given the GBC has quadruple the amount of work RAM (32 kB up from 8 kB) and double the amount of video RAM (16 kB up from 8 kB) compared to the DMC, and we're going to be running in GBC-exclusive mode, so we can make use of this extra memory for anything new while hopefully maintaining trade compatibility.