How to determine the number of a tile in a tilesheet?

[mattheweston]

I can use the following code to load a tile from a tileset and display it at 80,80. However, how are tiles numbered so I can tell what tile to load?

For example, if I have a tileset, and there is a tile in the middle of the tileset I want to load, how do I determine the number or the tile to load?

Code: Select all

  LDA #$80
  STA $0200        ;put sprite 0 in center ($80) of screen vertically
  STA $0203        ;put sprite 0 in center ($80) of screen horizontally
  LDA #$00
  STA $0201        ;tile number = 0
  STA $0202        ;color palette = 0, no flipping

  LDA #%10000000   ; enable NMI, sprites from Pattern Table 0
  STA $2000

  LDA #%00010000   ; no intensify (black background), enable sprites
  STA $2001

[thefox]

A good graphics editor like YY-CHR will display you the tile number in the status bar when you hover your cursor over a tile.

[mikaelmoizt]

If you have FCEUX, you can simply go to Debug -> PPU Viewer and take a look at your tilemap in your ROM.

[JRoatch]

So arrange like that then the "middle" tiles are 119, 120, 135, and 136 in decimal. Also keep in mind the sprite mode in $2000. nesdev wiki on Sprites