SEGA Mark III
Released October 20, 1985 in Japan. The refined successor to SG-1000/SC-3000, later evolving into the overseas Master System.
At a Glance
- Manufacturer: SEGA
- Launch (Japan): 1985-10-20
- Lineage: Successor to SG-1000; basis for the Master System overseas
- Media: ROM cartridges & My Card (Sega Card)
- Notable add-on: FM Sound Unit (enhanced music on supported titles)
Design & Features
Mark III refined Sega’s 8-bit platform with improved video output, support for both cartridges and thin “My Card” media, and optional FM synthesis via the add-on unit. Many later games were forward-compatible with overseas Master System hardware (with regional nuances and BIOS differences).
FM Sound
The FM Sound Unit added lush FM music to select titles—an audiophile favorite that gave Sega’s 8-bit library a unique flavor in Japan.
Accessories & I/O
Card slot, cartridge slot, 3-D glasses support (in later Master System units), and a growing peripheral ecosystem marked Sega’s ambitions.
Games & Impact
With strong arcade conversions and original IP, Mark III/Master System carved a distinct identity alongside Nintendo’s Famicom. While its market share in Japan lagged behind, its technical features and arcade lineage nurtured a passionate fan base.
- Fantasy Zone, Space Harrier, Alex Kidd in Miracle World, Phantasy Star (Master System)
- Arcade-style visuals and, with FM audio, richer soundscapes on supported titles
Collector’s Notes
- Regional nuance: Many carts/cards are cross-compatible with the Master System, but packaging and labels differ.
- FM Unit: Highly sought; verify functionality and bundle contents (brackets/cables).
- Condition checks: Controller ports, card slot reliability, and aging capacitors on older units.
Specs (Quick)
- CPU: Zilog Z80 @ ~3.6–4 MHz (family)
- Video: Up to 256×192; 32 colors palette (simultaneous colors vary)
- Audio: PSG (SN76489); optional FM synthesis via add-on
- Media: Cartridges & Sega My Card