What is a flash cartridge?

[Warrior]

You speak to generally. Not all flash carts support SD technology. You're talking about GBA only and the OP was talking about NES. I don't actually own any flash carts that support SD, mine all flash to a single-rom eeprom which can be erased and reprogrammed.

Yeah sorry, I was just spoutin what I knew , I kinda forgot about eeprom....

Well here is the only NES Flash Cart I know of, and it aint cheap

http://www.retrousb.com/product_info.php?products_id=34

[Zorlon]

http://www.raphnet.net/electronique/...es_cart_en.php NES DIY flashy thing

The biggest issue with all NES kits is that there are just too many Mappers, so there will always be something that does not work

For retro consoles I would say use emulation and get a USB pad converter and hook a PC up to a TV, if you want that retro feel best to use a CRT TV using Yellow composite (Red+White for sound, think the NES was mono though) or RGB Scart

Myself I would find more use for flashable devices for consoles that have poor emulation like the N64 and for portable consoles that just don't have the same feel when emulated on a large screen, especially systems like the DS with special features like a touch screen and mic that doesn't translate to mouse too well

Most of my emulation though is done through my TV via my Xbox (hacked with a custom dashboard (A software hack aka soft mod)), secondly via the Wii for light gun games (hacked via software aka soft mod).

Other emulation is done either via my PSP (using custom firmware (A software hack aka soft mod)) or 3DS (using a flash kit) [any DS system can use the up to date DS flash kits] to emulate other hand held systems.

I used to use a GBA for emulation also back in the day via a couple of flash kits an EZFA (Not to be confused with EZ Flash Advance #, it was a different flash kit) then a M3 lite with micro SD slot, both are going to be near impossible to get now, but they worked very well for GameGear, GameBoy to GameBoy Color NES & Mastersystem emulation to name a few.

Other mods can be boot discs, carts designed to bypass certain protection, usually used as part of a disc swap trick (Common for older PSX's that used a cheap Action replay clone that stopped the disc before booting the game allowing users to change from a retail disc to a CD-R, not recommended though for any games with multi discs that only allowed the change of discs while in play) and there is the mod chip method that is very much a hard mod, i.e. you are changing part of the internal hardware by soldering in a mod chip, this what it suggests, it's a micro chip.

Mod chips are more commonly used with CD, DVD & BD console systems to allow home burned media to run

Not everything that is emulated will work 100% perfect even for some of the more retro systems.

[Ragnar]

I was sure there was a CD kit also (for none CD consoles, do not quote me there)

The N64 had those. It made sense at the time, given the size of the games, and lack of other formats to store large data easily on. I believe there have been much better N64 products released since them, but they're still cool IMO.

[Zorlon]

That's what I was thinking of

The floppy system I seem to remember being for the Megadrive/Genesis it was big 5 1/4 drive as well so not thinking of the unreleased floppy drive that was planned but never released, just as well that would be like inviting pirates.

That will not be the only floppy type flash kit though there will of been others but the Megadrive one I have seen a real one.