understanding the nintendo ds card reader

 ❥ released 2006.11.22

❥ MSRP: 5,800 yen (converted to USD is $36.22)

❥ Developer/creator: SEGA

Hardware usage

• It's plugged into the GBA slot of a Nintendo DS lite, and is only functional with three games that were developed for usage of the card reader.
• Apparently, every game that supports this device comes included with it, typically in a box fashion.
• Other names/terminology: Slot-2 device

Inner mechanics

❧ Once the "slot-2 device" is inside of the Nintendo DS, the software will try to read the mapped data to the GBA cart ROM.  The device is not a GBA cart, but it will return certain values when the Nintendo DS tries to understand that area of memory.  Keep in mind that since every "slot-2 device" is unique, it will return a specific pattern/series of bytes. The game can now determine if the correct accessory is installed.

❧ So this little device reverse engineers the DS Lite. The first stage of this is considered detecting the device. The software will run a number of tests to determine if something is really there, and determine what that something is. It can be comparable for searching for an ID.

Within Oshare Majo Love and Berry

• If the card reader is not detected, the game will display a warning.

Emulation progress has made it possible to have the most realistic engagement with the video games on your PC. 

I did not research this individually by myself, I used several online sources to help me with this post. Thanks for reading.

- Mod Nanami