The Video Display Processor handles the Genesis' tile graphics, scroll planes, and sprites. There is 64KByte of VRAM.

Screen Resolution

NTSC

• H40 mode - 320x224px (40x28 8x8 tiles)
• H32 mode - 256x224px (32x28 8x8 tiles)

PAL

• H40 mode - 320x240px (40x30 8x8 tiles)
• H32 mode - 256x240px (32x30 8x8 tiles)

Graphics Planes

2 scroll planes

• Plane B - Background Plane
  • Displays tile graphcis via tile maps
• Plane A - Foreground Plane
  • Displays tile graphcis via tile maps
  • Window subplane - subplane for plane A, with tile graphics that does not scroll with the rest of the plane
• Each row of tiles is rendered column-by-column
• Tiles on each plane can have priority low or high

1 Sprite Plane

• Draws sprite tile graphics
• Internally, sprites are rendered in reverse order; i.e., each column of tiles is rendered by rows.
• Sprites are positioned in a virtual 512x512 grid with 128x128 the top left corner of the display
• Genesis can display up to 80 hardware sprites simultaneously
• 20 sprites can be rendered on the same scanline before flicker
• Sprite sizes can be 1-4 tiles big (each tile is 8x8), combining them can make larger sprites
• Sprites can have high or low priority. Low priority sprites are displayed behind high priority tiles in other layers.