Manufacturer: Sega Released: 1991 Units sold: 2.24 million (CD-ROM add-on) Best-selling game: Sewer Shark CPU: 16-bit Motorola 68000 @ 12.5 MHz + Mega Drive CPUs RAM: 512 KB / VRAM: 256 KB / Sound RAM: 16 KB Graphics: Custom ASIC Resolution: 320×224 pixels, 64 colors (512 color palette) Sound: Ricoh RF5C164 + Mega Drive sound chips Media: 500 MB CD-ROM, CD+G