Print a string

Family 1 — Text · rung 1.1 (the built-in font)

The gentlest program that still exercises the whole SNES rhythm — tiles, palette, VRAM and the VBlank handshake — on the smallest possible surface. It prints one string in white on a dark blue screen and idles. If text ever breaks, this is the simplest ROM that reveals it.

Screenshot

What you'll learn

• The OpenSNES text module in one call: textModeInit() configures the hardware and the text engine, then textPrintAt(col, row, "…") writes to an off-screen buffer.
• The NMI handler DMAs that buffer to VRAM as a tilemap on the next VBlank — no manual textFlush() needed on this path.
• Colour 0 is the universal backdrop; setColor(0, RGB(r,g,b)) sets it.
• setScreenOn() is called last, after a WaitForVBlank(), so all VRAM writes land during blanking (no garbage first frame).

SNES concepts

The SNES has no text hardware. Characters are background tiles: a font lives in VRAM as tiles, and a tilemap maps each screen cell to a tile index. The text module owns both — you just call textPrintAt. Mode 0 is used because the built-in font is 2bpp (4 colours), which is all monochrome text needs.

How to build

make -C examples/text/print_string

Then run print_string.sfc in luna (or any SNES emulator). You should see TEXT MODULE TEST in white on dark blue.

Modules used

console, dma, text, background, sprite

Next rung

→ 1.2 Load a custom font from a PNG · under the hood: how a glyph is 2bpp bitplanes + a tilemap → fundamentals/text_glyphs.