Originally Posted by
Tanooki
I can explain that one, it is out there, but you have to dig, and it's exclusive to the NES alone.
Nintendo and their mapper system, all those myriad of chips are to blame along with the fact the R5 itself has a massive CRC checklist within the system. It will look at the game, read the CRC and use the database to tell the emulator what mapper to fire up, just like the classic .NES headers do. When a game has NO header (ie: copier cart) the system can not see it at all and you get an error. If it has one, even as a multicart, it will attempt to read it. It will either pull up the menu but never get into the individual games, or it will just straight up fail. And in the case of a singular cart where it can not find a matching CRC the system will go into a fallback mode and scan the game and attempt load it using .NES mapper 0-4, the most basic stuff, which like 90% of NES games use anyway. That would work, but odds are a game that saves will have a problem I'd think since it wouldn't find the thing twice to pull the data again.
Armed for Battle doesn't use mapper0-4, and the data on the cart isn't public info I don't believe for what the CRC is on it, so it won't work in the R5. If you had that info, and you facebook messaged the Retron Tech, they'd attempt to add it though. I did this on a few things including the Supervision 115in1 pirate cart I have and that one works 100% because of it, one of few pirate multicarts that play. Again this only applies to the NES, if you have various bootlegs for other systems that are not multi-carts, they should work fine on the system. Other than 1 game the Genesis didn't use special chips, and the SNES only used Lo and HiROM cart boards and that's all mapped out so it just works, even games with special chips as my Starfox2 works fine. The other platforms it supports doesn't have issues either for the same reason, no wonky headers/chips to worry about.