Sega System 24
From Sega Retro
The Sega System 24 is an arcade platform released by Sega in the late 1980s. The System 24 is quite different from other "System" arcade boards - primarily it handles high resolution games with more colours, rather than serving as a direct successor to the standard Sega System 16 arcade hardware (this task was reserved for the Sega System 32).
The System 24 uses two Motorola 68000 processors at 10 MHz. One is for booting, while the other is used by the game. The board holds 1360KB of RAM and 256kB of ROM, and was the first Sega arcade system that required a medium resolution arcade monitor. 4352 colors can be used on-screen from a selectable 32,768, and the system can support up to 2048 sprites on-screen at once.
Sound is driven by a YM2151 at 4MHz; it is capable of delivering 8 channels of FM sound in addition to a DAC used for sound effects and speech synthesis. Early System 24s loaded their program off of floppy disks. Some later games such as Bonanza Bros. use CD-ROMs or hardware ROM boards as storage. No matter which storage device is used, a special security chip is required for each game an operator wants to play.