Sega Y Board

Fast Facts on the Sega Y Board
Made by: Sega Release Date RRP Code World 1988  ? {{#ifeq: 2 | 3 |

The Sega Y Board is an arcade system board released by Sega in 1988 as a successor to the Sega X Board. Like the X Board before it, the Y Board was known for its sprite manipulation capabilities.

The Y Board is quite different to the X Board in terms of design, offering a third CPU and more advanced video equipment. Most notably, the Y Board allows for real-time rotation of sprites as well as scaling. Unusually, the system uses no tile layers, so graphics are rendered using only sprites (a design taken by SNK for their Neo-Geo hardware in 1990).

Technical Specifications

• CPUs: 3 x MC68000 @ 12.5 MHz
  • The first 68000 ("main" in MAME) has access to the sound hardware, I/O hardware, and 64KB RAM
  • The second 68000 ("subx" in MAME) has access to the ysprites hardware, backup RAM and 16KB RAM
  • The third 68000 ("suby" in MAME) has access to the bsprites hardware, ysprites full plane rotation, bsprites palette RAM, and 64KB RAM
  • The three CPUs share 64KB of separate RAM for communication as well as the multiplier/divider hardware
• Sound CPU: Z80 @ 4 MHz with 2KB RAM
• Sound chip: YM2151 4 MHz & SegaPCM @ 15.625 MHz
• Display resolution: 320 x 224
• Board composition: CPU board and video board
• Video hardware:
  • Two sprite planes with fixed Z-order
  • Lower sprite plane ("ysprites" in MAME): full scaling and rotation; also the entire plane can be rotated as a whole
    • Palettes are stored alongside the sprite table; sprite table entries hold a pointer to the palette, which itself is stored as an table of palette indirection values(?)
  • Higher sprite plane ("bsprites" in MAME): standard Sega System 16B sprite plane

List of Games

• G-LOC Air Battle (1990)
• Galaxy Force (1988)
• Galaxy Force II (1988)
• Power Drift (1988)
• Rail Chase (1991)
• Strike Fighter (1991)

Gallery

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  PCB (top)

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  PCB (bottom)