The Sega System 18 is an arcade system board released by Sega in 1989. The System 18 is primarily a soup-ed System 16, offering superior sound, more tile laters and extra graphics options.
System 18 boards had a very short run of games but most adhere to JAMMA standard, unlike previous systems. Most of these games also have the "suicide battery" as associated with Sega's System 16 hardware. It also contains the VDP used by the Sega Mega Drive console.
- Board composition: Main board + ROM board
- Main CPU: Motorola 68000 @ 10 MHz (16-bit & 32-bit instructions @ 1.75 MIPS)
- Sound CPU: Zilog Z80 @ 8 MHz (8-bit & 16-bit instructions @ 1.16 MIPS)
- Sound chips:
- 2× Yamaha YM3438 @ 8 MHz
- Ricoh RF5c68 @ 10 MHz (8-channel PCM chip, remarked as Sega Custom 315)
- Graphics chips:
- Display resolution: 320×224
- Color palette: 98,304 (16-bit)
- 16-bit color palette: 15-bit RGB high color depth (32,768 colors) and 1-bit shadow & highlight that triples up to 98,304 colors
- Colors on screen: 4096 (unique colors) to 8384 (with shadow & highlight)
- Graphical capabilities: 128 sprites on screen at one time, 4 tile layers, 1 text layer, 1 sprite layer with hardware sprite zooming, translucent shadows, sprites of any height and length, row & column scrolling
List of Games
- ↑ https://github.com/mamedev/mame/tree/master/src/mame/drivers/segas18.cpp