NSCR (NITRO-System Screen for Runtime) files store BG screen data for the 2D graphics engine. It follows the [NNS G2D Binary File Format|G2D Binary File Format]. NSCR files use file signature {{'NSCR'}}.

!!SCRN Block

The {{SCRN}} block stores the background screen data. The structure is as follows:

||Offset||Type||Meaning
| 0x00  | u16  | Width in pixels
| 0x02  | u16  | Height in pixels
| 0x04  | u32  | Screen data format. This can be Text BG (0), Affine BG (1), Affine EXT BG (2), Bitmap BG (3), or Direct Color BG (4).
| 0x08  | u32  | Screen data size
| 0x0C  | u8[[...] | BG Screen data (variable size)

!Data Format

For Text and Affine EXT, the format is:
{{{
PPPP VH CCCCCCCCCC
|    || |
|    || +--------- Character index
|    |+----------- Horizontal flip
|    +------------ Vertical flip
+----------------- Palette index
}}}

For Affine BGs, the format is just an 8-bit character index per tile and does not allow for selecting multiple palettes or tile flipping.