bmp files into the _system_ directory on the MicroSD card.
Moonshell is a separate Application, and is a piece of Homebrew software itself and can be used for viewing text files, pictures, and mp3's. NDS files which are either Homebrew applications or Games in the form of ROM files.
This section will allow you to browse the files on the card for. In this review, I will be using a Kingston 1gb MicroSD (SD-C01G JAPAN) card with the R4 and all associated benchmarks. Let's talk about the launcher, there are 3 items here, they represent: NDS Apps, Moonshell, and Boot Slot-2. The R4 (Revolution for DS) is another slot 1 solution which uses a MicroSD card to store all the necessary data, from ROMs and music to the operating system files.