The NES’s PPU (Picture Processing Unit) generates a composite video signal with 240 scanlines. This signal is compatible with the color television standards of the era: NTSC in Japan and the Americas, PAL in Europe.
PPU specifications:
• 256x240 visible resolution
• 64 colors (56 unique)
• 8x8 tiles, four colors per pixel (one transparent)
• 512 possible character patterns at one time
• 32x60 or 64x30 scrollable tile map in RAM
• 64 8x8 (or 8x16) sprites, up to eight sprites per scanline