zerowalker wrote:
Btw why would i want several GameBoys, one expects them to break?
You'll need at least two if you want to do hardware tests on multiplayer stuff (standard 2-player stuff e.g. Pokemon battles/trading). It's not necessary, but yes, having a backup is always a good idea. Game Boys are pretty durable and fixable, but I myself somehow ended up having 8 (1 DMG, 2 Pockets, 2 GBCs, 1 AGB-001, 1 AGS-001, and 1 AGS-101).
zerowalker wrote:
I mean one would want to be able to have something that can test the weird quirks right?
Anything that's MBC1, MBC3, or MBC5 is good enough for testing. Most flashcarts are programmable, so whatever ROM you put inside will determine what kind of MBC it simulates (it checks the header). I generally stick to 32KB MBC1 ROM + RAM + Battery. Test ROMs are generally very, very small, and I like to save any results to the cart RAM so I can analyze things in a hex editor later. I have a cart reader, so I can pull up the save file as a binary. If you don't have a cart reader, you'll have to come up with visual "PASS/FAIL" graphics and print things to the screen like blargg's tests.
zerowalker wrote:
Can't imagine where 4 players would be of use on a Gameboy, how it would even process that external information.
If you're interested,
I write a bunch of articles about emulation, so once I finish implementing the DMG-07 4 Player Adapter in my emulator, I'll post a very detailed explanation about how it works. Without going into much detail, the DMG-07 basically pings the status of all connected Game Boys and broadcasts that to each. So each Game Boy knows which one is connected and which player it is (e.g. Player 1, Player 2, Player 3, or Player 4). Player 1 acts as master, all other Game Boys are slaves. Player 1 starts the synchronization process, and then each Game Boy basically takes turns sending data over the link cables (starts with Player 1, ends with Player 4, repeats). The DMG-07 is responsible for broadcasting the data to each Game Boy, so anything Player 1 sends, Players 2, 3, and 4 also receive. Anything Player 2 sends, Players 1, 3, and 4 receive, and so on.
It's really fascinating, but it ended up being used by like only a dozen or so games. By the mid-1990s, it had been totally forgetten. 4-player support was an afterthought for the original Game Boy, while the Game Boy Advance handled it like a professional