Hardware GBA Wireless Adapter/Link Cable

[QuestionEmulation]

Had a few questions relating to how Nintendo connected Game Boys of all types of multi gaming.

• Any clue how games were written to detect the link cable pre Wireless adapter?
• Any clue how games were written to detect the wireless adapter for the few games that supported it?

Just wondering if anyone had any clue or could point me in the right direction

 

[Deleted member 514389]

Thats all I could find so far
https://douevenknow.us/post/132200462733/dumping-the-gba-wireless-adapter-firmware

gbadev.org is probably the best resource for such question.

 

[FAST6191]

Not something I have properly investigated but links for all

https://gbatemp.net/threads/talk-on-reverse-engineering-the-gba-link-protocol.532989/

http://problemkaputt.de/gbatek.htm#gbacommunicationports
http://problemkaputt.de/gbatek.htm#gbawirelessadapter

 

[QuestionEmulation]

Thank you both

 

[DanTheManMS]

https://gbatemp.net/threads/talk-on-reverse-engineering-the-gba-link-protocol.532989/

This sent me on a fun rabbit-hole of various Youtube documentaries, thank you legitimately. Interesting to see that they sent 18 bits at a time for 16 bits of data, with the first and final being checksum bits.

I once tried to wire up my own SNES-controller-to-GBA link cable. It was supposed to be a simple matter of cutting each cable in half and splicing the right wires together. I had/have the schematics, I have the "buttontester.gba" file that's been sitting on my Supercard for decades. There was a special version of SNES Advance that could use the custom hacked controller hookup, and I even managed to track down a patcher program that would let *any* GBA rom file work with it, not just SNES Advance. I was so excited to be so close!

But *every single GBA link cable* I could possibly find only used 4 of the 6 wires. I tried official cables from Nintendo and Gamestop, unofficial cables from DealExtreme when that was a thing, even an official GBA-to-Gamecube link cable I sacrificed just to find out that nope, it only had 4 wires too. And those are too expensive now to try again.

Either I did something terribly, terribly wrong, or I have to assume that 95% of GBA link cables don't include all 6 cables for cost reasons.

 

[FAST6191]

This sent me on a fun rabbit-hole of various Youtube documentaries, thank you legitimately.

If you found that sort of thing interesting I would highly suggest the "ultimate" series for various consoles and such like from the C3 hacker conference. Most years there will be one or two that cover a console in serious depth (or as serious as you get in an hour when you assume your audience is composed of technically capable people).
https://www.youtube.com/c/mediacccde/search?query=ultimate (nowadays the main channel for the CCC hacker conference and related stuff)
https://www.youtube.com/c/ChRiStIaAn008/search?query=ultimate for the older ones.
https://www.youtube.com/user/HackersOnBoard/search?query=ultimate has a few as well.


https://loveconquersallgam.es/post/2350461718/fuck-the-super-game-boy-introduction is also good stuff if we are onto SNES things.


On many wires link cable. Somewhat surprising there as I thought there would be some when looking at http://problemkaputt.de/gbatek.htm#auxlinkport, sure some wires have jumpers to other wires so could expect to see it at the port end.

I have often toyed with making custom ports for various game console custom ports such that people could solder whatever they like but I am not sure I can make them a price people want to pay vs doing the same for cars where "so you are telling me I don't need to buy a new wiring harness"

That said "a patcher program that would let *any* GBA rom file work with it"
I am dubious there. You can program in something to run a small line of cheat code, a sleep command or soft rest command as a generic patcher for 99% of games (Phantasy Star collection likely being the main exception for the same reasons as https://gamehacking.org/wiki/Hacking_Game_Boy_Advance#Hacking_Nonstandard_Master_Codes ) but altering controller inputs or redirecting them is not that -- as far as I know the controller state register is read only and after that you have a mess of debouncing and individual commands to look at. Or if you prefer that we don't have a simple remap this button to this button tool on par with gbaatm or boma or whatever GBATA has in the same realm says most things I need to know there. If a game is debounced then it would not be the worst hack in the world to copy the link port state to a debounce location but it would be on a per ROM basis.
http://problemkaputt.de/fullsnes.htm#snescontrollerspinouts
and
http://problemkaputt.de/fullsnes.htm#snescontrollers
have me wondering as to the merits of the simple straight through connection as well, though http://www.brolinembedded.se/projects/keyboard/ would stand in opposition to that I suppose and https://www.instructables.com/SNES-Teensy-USBPS3-Gamepad/ says much as well.

 

[DanTheManMS]

You've given me a LOT of good links to peruse through, thank you! I'll be at that for a while.

That said "a patcher program that would let *any* GBA rom file work with it"
I am dubious there. You can program in something to run a small line of cheat code, a sleep command or soft rest command as a generic patcher for 99% of games but altering controller inputs or redirecting them is not that

Yeah, I'm aware of things like Dwedit's patches to hook into games for a button combo to activate sleep mode or soft-reset or something simple like that, and that's what made it so unbelievable! I honestly didn't believe it until I found it. Attached are the files I have archived, untouched from the moment I saved them.

The first is the patched version of SNES Advance for the controller, the second is another modified version to work with both the controller AND the GBAccelerator overclock mod, and the last one is the most interesting to us: the generic patcher that claims to work on any GBA rom file.

The text files in some of those zip files show the proper pinout connections, might need to replace a couple "&nbsp" parts with actual blank spaces to make them more readable.