This is done with an R4 chip: buy one: http://www.ts-shops.eu/nintendo-dsi-xl/flash-cards There’s a difference between the r4 and r4i You then put a kernel on the chip: http://www.r4i-sdhc.com/downloade.asp Instructions for formatting your r4 card http://www.r4dscards.com/R4i-DS-Card/ Download games to put on: http://www.dgemu.com/